massive state space solver improvement: supercomp took ~10s, now ~40ms

achieved by imposing a 15 block limit on each board and changing the
internal representation from std::string to 4x uint64_t

.clang-format

@@ -0,0 +1,56 @@
+---
+Language: Cpp
+BasedOnStyle: LLVM
+AccessModifierOffset: -4
+AlignConsecutiveAssignments: false
+AlignConsecutiveDeclarations: false
+AlignOperands: false
+AlignTrailingComments: true
+AllowShortBlocksOnASingleLine: false
+AllowShortFunctionsOnASingleLine: None
+AllowShortIfStatementsOnASingleLine: true
+AllowShortLoopsOnASingleLine: true
+AlwaysBreakAfterDefinitionReturnType: false
+AlwaysBreakTemplateDeclarations: Yes
+BraceWrapping:
+  AfterCaseLabel: true
+  AfterClass: true
+  AfterControlStatement: false
+  AfterEnum: true
+  AfterFunction: true
+  AfterNamespace: true
+  AfterStruct: true
+  AfterUnion: true
+  AfterExternBlock: false
+  BeforeCatch: true
+  BeforeElse: false
+  BeforeLambdaBody: true
+  BeforeWhile: false
+  SplitEmptyFunction: false
+  SplitEmptyRecord: false
+  SplitEmptyNamespace: false
+BreakBeforeBraces: Custom
+ColumnLimit: 100
+IncludeCategories:
+  - Regex: '^<.*'
+    Priority: 1
+  - Regex: '^".*'
+    Priority: 2
+  - Regex: '.*'
+    Priority: 3
+IncludeIsMainRegex: '([-_](test|unittest))?$'
+IndentCaseBlocks: true
+IndentGotoLabels: false
+IndentPPDirectives: BeforeHash
+IndentWidth: 4
+InsertNewlineAtEOF: true
+MacroBlockBegin: ''
+MacroBlockEnd: ''
+PointerAlignment: Left
+SpaceInEmptyParentheses: false
+SpacesInAngles: false
+SpacesInConditionalStatement: false
+SpacesInCStyleCastParentheses: false
+SpacesInParentheses: false
+TabWidth: 4
+...

.clang-tidy

@@ -0,0 +1,145 @@
+# Generated from CLion Inspection settings
+---
+Checks: '-*,
+bugprone-argument-comment,
+bugprone-assert-side-effect,
+bugprone-bad-signal-to-kill-thread,
+bugprone-branch-clone,
+bugprone-copy-constructor-init,
+bugprone-dangling-handle,
+bugprone-dynamic-static-initializers,
+bugprone-fold-init-type,
+bugprone-forward-declaration-namespace,
+bugprone-forwarding-reference-overload,
+bugprone-inaccurate-erase,
+bugprone-incorrect-roundings,
+bugprone-integer-division,
+bugprone-lambda-function-name,
+bugprone-macro-parentheses,
+bugprone-macro-repeated-side-effects,
+bugprone-misplaced-operator-in-strlen-in-alloc,
+bugprone-misplaced-pointer-arithmetic-in-alloc,
+bugprone-misplaced-widening-cast,
+bugprone-move-forwarding-reference,
+bugprone-multiple-statement-macro,
+bugprone-no-escape,
+bugprone-parent-virtual-call,
+bugprone-posix-return,
+bugprone-reserved-identifier,
+bugprone-sizeof-container,
+bugprone-sizeof-expression,
+bugprone-spuriously-wake-up-functions,
+bugprone-string-constructor,
+bugprone-string-integer-assignment,
+bugprone-string-literal-with-embedded-nul,
+bugprone-suspicious-enum-usage,
+bugprone-suspicious-include,
+bugprone-suspicious-memset-usage,
+bugprone-suspicious-missing-comma,
+bugprone-suspicious-semicolon,
+bugprone-suspicious-string-compare,
+bugprone-suspicious-memory-comparison,
+bugprone-suspicious-realloc-usage,
+bugprone-swapped-arguments,
+bugprone-terminating-continue,
+bugprone-throw-keyword-missing,
+bugprone-too-small-loop-variable,
+bugprone-undefined-memory-manipulation,
+bugprone-undelegated-constructor,
+bugprone-unhandled-self-assignment,
+bugprone-unused-raii,
+bugprone-unused-return-value,
+bugprone-use-after-move,
+bugprone-virtual-near-miss,
+cert-dcl21-cpp,
+cert-dcl58-cpp,
+cert-err34-c,
+cert-err52-cpp,
+cert-err60-cpp,
+cert-flp30-c,
+cert-msc50-cpp,
+cert-msc51-cpp,
+cert-str34-c,
+cppcoreguidelines-interfaces-global-init,
+cppcoreguidelines-narrowing-conversions,
+cppcoreguidelines-pro-type-member-init,
+cppcoreguidelines-pro-type-static-cast-downcast,
+cppcoreguidelines-slicing,
+google-default-arguments,
+google-runtime-operator,
+hicpp-exception-baseclass,
+hicpp-multiway-paths-covered,
+misc-misplaced-const,
+misc-new-delete-overloads,
+misc-non-copyable-objects,
+misc-throw-by-value-catch-by-reference,
+misc-unconventional-assign-operator,
+misc-uniqueptr-reset-release,
+modernize-avoid-bind,
+modernize-concat-nested-namespaces,
+modernize-deprecated-headers,
+modernize-deprecated-ios-base-aliases,
+modernize-loop-convert,
+modernize-make-shared,
+modernize-make-unique,
+modernize-pass-by-value,
+modernize-raw-string-literal,
+modernize-redundant-void-arg,
+modernize-replace-auto-ptr,
+modernize-replace-disallow-copy-and-assign-macro,
+modernize-replace-random-shuffle,
+modernize-return-braced-init-list,
+modernize-shrink-to-fit,
+modernize-unary-static-assert,
+modernize-use-auto,
+modernize-use-bool-literals,
+modernize-use-emplace,
+modernize-use-equals-default,
+modernize-use-equals-delete,
+modernize-use-nodiscard,
+modernize-use-noexcept,
+modernize-use-nullptr,
+modernize-use-override,
+modernize-use-transparent-functors,
+modernize-use-uncaught-exceptions,
+mpi-buffer-deref,
+mpi-type-mismatch,
+openmp-use-default-none,
+performance-faster-string-find,
+performance-for-range-copy,
+performance-implicit-conversion-in-loop,
+performance-inefficient-algorithm,
+performance-inefficient-string-concatenation,
+performance-inefficient-vector-operation,
+performance-move-const-arg,
+performance-move-constructor-init,
+performance-no-automatic-move,
+performance-noexcept-move-constructor,
+performance-trivially-destructible,
+performance-type-promotion-in-math-fn,
+performance-unnecessary-copy-initialization,
+performance-unnecessary-value-param,
+portability-simd-intrinsics,
+readability-avoid-const-params-in-decls,
+readability-const-return-type,
+readability-container-size-empty,
+readability-convert-member-functions-to-static,
+readability-delete-null-pointer,
+readability-deleted-default,
+readability-inconsistent-declaration-parameter-name,
+readability-make-member-function-const,
+readability-misleading-indentation,
+readability-misplaced-array-index,
+readability-non-const-parameter,
+readability-redundant-control-flow,
+readability-redundant-declaration,
+readability-redundant-function-ptr-dereference,
+readability-redundant-smartptr-get,
+readability-redundant-string-cstr,
+readability-redundant-string-init,
+readability-simplify-subscript-expr,
+readability-static-accessed-through-instance,
+readability-static-definition-in-anonymous-namespace,
+readability-string-compare,
+readability-uniqueptr-delete-release,
+readability-use-anyofallof'

.gitignore

@@ -5,3 +5,4 @@ cmake-build-release
 /result
 /.gdb_history
 /valgrind.log
+.idea

CMakeLists.txt

@@ -4,9 +4,66 @@ project(MassSprings)
 set(CMAKE_CXX_STANDARD 26)
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 
-# set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wextra -Wfloat-equal -Wundef -Wshadow -Wpointer-arith -Wcast-align -Wno-unused-parameter -Wunreachable-code")
-set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -O2 -ggdb") # -fsanitize=address already fails on InitWindow(), -fsanitize=undefined, -fsanitize=leak
-set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -Ofast -march=native")
+if(POLICY CMP0167)
+    cmake_policy(SET CMP0167 NEW)
+endif()
+
+option(DISABLE_BACKWARD "Disable backward stacktrace printer" OFF)
+option(DISABLE_TRACY "Disable the Tracy profiler client" ON)
+option(DISABLE_TESTS "Disable building and running tests" ON)
+
+# Headers + Sources
+set(SOURCES
+    src/backward.cpp
+    src/graph_distances.cpp
+    src/input_handler.cpp
+    src/mass_spring_system.cpp
+    src/octree.cpp
+    src/orbit_camera.cpp
+    src/renderer.cpp
+    src/state_manager.cpp
+    src/threaded_physics.cpp
+    src/user_interface.cpp
+    src/puzzle.cpp
+)
+
+# Libraries
+find_package(raylib REQUIRED)
+find_package(Boost REQUIRED)
+set(LIBS raylib Boost::headers)
+set(FLAGS "")
+
+if(WIN32)
+    list(APPEND LIBS opengl32 gdi32 winmm)
+endif()
+
+include(FetchContent)
+if(NOT DISABLE_BACKWARD)
+    find_package(Backward REQUIRED)
+
+    list(APPEND LIBS Backward::Backward)
+    list(APPEND FLAGS BACKWARD)
+endif()
+
+if(NOT DISABLE_TRACY)
+    FetchContent_Declare(tracy
+                         GIT_REPOSITORY https://github.com/wolfpld/tracy.git
+                         GIT_TAG v0.11.1
+                         GIT_SHALLOW TRUE
+                         GIT_PROGRESS TRUE
+    )
+    FetchContent_MakeAvailable(tracy)
+    option(TRACY_ENABLE "" ON)
+    option(TRACY_ON_DEMAND "" ON)
+
+    list(APPEND LIBS TracyClient)
+    list(APPEND FLAGS TRACY)
+endif()
+
+# Set this after fetching tracy to hide tracy's warnings
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wextra -Wfloat-equal -Wundef -Wshadow -Wpointer-arith -Wcast-align -Wno-unused-parameter -Wunreachable-code")
+set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -ggdb -O0")
+set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -ggdb -Ofast -march=native")
 
 message("-- CMAKE_C_FLAGS: ${CMAKE_C_FLAGS}")
 message("-- CMAKE_C_FLAGS_DEBUG: ${CMAKE_C_FLAGS_DEBUG}")
@@ -15,59 +72,42 @@ message("-- CMAKE_CXX_FLAGS: ${CMAKE_CXX_FLAGS}")
 message("-- CMAKE_CXX_FLAGS_DEBUG: ${CMAKE_CXX_FLAGS_DEBUG}")
 message("-- CMAKE_CXX_FLAGS_RELEASE: ${CMAKE_CXX_FLAGS_RELEASE}")
 
-find_package(raylib REQUIRED)
-find_package(Backward REQUIRED)
-
-# Headers + Sources
-include_directories(include)
-set(SOURCES
-    src/main.cpp
-    src/camera.cpp
-    src/renderer.cpp
-    src/octree.cpp
-    src/physics.cpp
-    src/puzzle.cpp
-    src/state.cpp
-    src/input.cpp
-    src/tracy.cpp
-    src/backward.cpp
-    src/distance.cpp
-    src/gui.cpp
-)
-
 # Main target
-add_executable(masssprings ${SOURCES})
-target_include_directories(masssprings PUBLIC ${RAYLIB_CPP_INCLUDE_DIR})
-target_link_libraries(masssprings PUBLIC raylib Backward::Backward)
+add_executable(masssprings src/main.cpp ${SOURCES})
+target_include_directories(masssprings PRIVATE include)
+target_link_libraries(masssprings PRIVATE ${LIBS})
+target_compile_definitions(masssprings PRIVATE ${FLAGS})
 
-# Tracy target
-if(USE_TRACY)
-    include(FetchContent)
-    FetchContent_Declare(tracy
-        GIT_REPOSITORY https://github.com/wolfpld/tracy.git
-        GIT_TAG v0.11.1
-        GIT_SHALLOW TRUE
-        GIT_PROGRESS TRUE
+# Testing sources
+if(NOT DISABLE_TESTS AND NOT WIN32)
+    enable_testing()
+
+    FetchContent_Declare(Catch2
+        GIT_REPOSITORY https://github.com/catchorg/Catch2.git
+        GIT_TAG v3.13.0
     )
-    FetchContent_MakeAvailable(tracy)
-    option(TRACY_ENABLE "" ON)
-    option(TRACY_ON_DEMAND "" ON)
+    FetchContent_MakeAvailable(Catch2)
 
-    add_executable(masssprings_tracy ${SOURCES})
-    target_include_directories(masssprings_tracy PUBLIC ${RAYLIB_CPP_INCLUDE_DIR})
-    target_compile_definitions(masssprings_tracy PRIVATE TRACY)
-    target_link_libraries(masssprings_tracy PUBLIC raylib Backward::Backward TracyClient)
+    set(TEST_SOURCES
+        test/bits.cpp
+    )
+
+    add_executable(tests ${TEST_SOURCES} ${SOURCES})
+    target_include_directories(tests PRIVATE include)
+    target_link_libraries(tests Catch2::Catch2WithMain raylib)
+
+    include(Catch)
+    catch_discover_tests(tests)
 endif()
 
 # LTO
+#if(NOT WIN32)
 include(CheckIPOSupported)
 check_ipo_supported(RESULT supported OUTPUT error)
 if(supported)
     message(STATUS "IPO / LTO enabled")
     set_property(TARGET masssprings PROPERTY INTERPROCEDURAL_OPTIMIZATION TRUE)
-    if(USE_TRACY)
-        set_property(TARGET masssprings_tracy PROPERTY INTERPROCEDURAL_OPTIMIZATION TRUE)
-    endif()
 else()
-    message(STATUS "IPO / LTO not supported: <${error}>")
+    message(STATUS "IPO / LTO not supported")
 endif()
+#endif()

README.md

@@ -0,0 +1,16 @@
+# MassSprings - Puzzle Board State Space Explorer
+
+All combinations of pieces reachable from an initial puzzle are explored, the resulting puzzle state-space is visualized as a force-directed graph.
+The graph layout is calculated iteratively using a mass-spring-system with additional pairwise repulsive forces simulated using Barnes-Hut.
+
+![](screenshot.png)
+
+## Running
+
+Requirements:
+
+- Directory `fonts`
+- Directory `shader`
+- Preset file `default.puzzle` (optional)
+
+Run `nix run git+https://gitea.local.chriphost.de/christoph/cpp-masssprings` from the working directory containing the listed requirements.

default.puzzle

@@ -1,44 +1,30 @@
 # RushHour 1
-R664231........13................12ba..........1221..12..12..21........31....
-
+S:[6x6] G:[4,2] M:[R] B:[{3x1 _ _ _ _ 1x3} {_ _ _ _ _ _} {_ _ 1x2 2X1 _ _} {_ _ _ 1x2 2x1 _} {1x2 _ 1x2 _ 2x1 _} {_ _ _ 3x1 _ _}]
 # RushHour 2
-R66421231....1213..31........ba..121212..21................1221..........21..
-
+S:[6x6] G:[4,2] M:[R] B:[{1x2 3x1 _ _ 1x2 1x3} {_ 3x1 _ _ _ _} {2X1 _ 1x2 1x2 1x2 _} {2x1 _ _ _ _ _} {_ _ _ 1x2 2x1 _} {_ _ _ _ 2x1 _}]
 # RushHour 3
-R664231....12....1221......12..ba..1212..21..12....12......21......21..21....
-
+S:[6x6] G:[4,2] M:[R] B:[{3x1 _ _ 1x2 _ _} {1x2 2x1 _ _ _ 1x2} {_ 2X1 _ 1x2 1x2 _} {2x1 _ 1x2 _ _ 1x2} {_ _ _ 2x1 _ _} {_ 2x1 _ 2x1 _ _}]
 # RushHour 4
-R66421321....12....1212....13......ba....31....12........12..21..21....21....
-
+S:[6x6] G:[4,2] M:[R] B:[{1x3 2x1 _ _ 1x2 _} {_ 1x2 1x2 _ _ 1x3} {_ _ _ 2X1 _ _} {3x1 _ _ 1x2 _ _} {_ _ 1x2 _ 2x1 _} {2x1 _ _ 2x1 _ _}]
 # RushHour + Walls 1
-R66421221..AA..........1221..12ba............1221..1321..........21..31......
-
+S:[6x6] G:[4,2] M:[R] B:[{1x2 2x1 _ 1*1 _ _} {_ _ _ 1x2 2x1 _} {1x2 2X1 _ _ _ _} {_ _ 1x2 2x1 _ 1x3} {2x1 _ _ _ _ _} {2x1 _ 3x1 _ _ _}]
 # RushHour + Walls 2
-R664221....1212AA31..........12ba..12........12..21........21..12....21..AA..
-
+S:[6x6] G:[4,2] M:[R] B:[{2x1 _ _ 1x2 1x2 1*1} {3x1 _ _ _ _ _} {1x2 2X1 _ 1x2 _ _} {_ _ 1x2 _ 2x1 _} {_ _ _ 2x1 _ 1x2} {_ _ 2x1 _ 1*1 _}]
 # Dad's Puzzler
-F4503bb..21......21..1111....121221......21..
-
-# Nine Block (Worse)
-F45031212........21..121221......bb..1111....
-
+S:[4x5] G:[0,3] M:[F] B:[{2X2 _ 2x1 _} {_ _ 2x1 _} {1x1 1x1 _ _} {1x2 1x2 2x1 _} {_ _ 2x1 _}]
+# Nine Blocks
+S:[4x5] G:[0,3] M:[F] B:[{1x2 1x2 _ _} {_ _ 2x1 _} {1x2 1x2 2x1 _} {_ _ 2X2 _} {1x1 1x1 _ _}]
 # Quzzle
-F4520bb..21......1212........1221..11..21..11
-
+S:[4x5] G:[2,0] M:[F] B:[{2X2 _ 2x1 _} {_ _ 1x2 1x2} {_ _ _ _} {1x2 2x1 _ 1x1} {_ 2x1 _ 1x1}]
 # Thin Klotski
-F451412..ba....22..11......1122..1111....1111
-
-# Klotski
-F451312bb..12........1221..12..1111..11....11
-
+S:[4x5] G:[1,4] M:[F] B:[{1x2 _ 2X1 _} {_ 2x2 _ 1x1} {_ _ _ 1x1} {2x2 _ 1x1 1x1} {_ _ 1x1 1x1}]
 # Fat Klotski
-F4513..bb..1111....121122....11......111121..
-
+S:[4x5] G:[1,3] M:[F] B:[{_ 2X2 _ 1x1} {1x1 _ _ 1x2} {1x1 2x2 _ _} {1x1 _ _ _} {1x1 1x1 2x1 _}]
+# Klotski
+S:[4x5] G:[1,3] M:[F] B:[{1x2 2X2 _ 1x2} {_ _ _ _} {1x2 2x1 _ 1x2} {_ 1x1 1x1 _} {1x1 _ _ 1x1}]
 # Century
-F451311bb..1112....12..12....11....1121..21..
-
+S:[4x5] G:[1,3] M:[F] B:[{1x1 2X2 _ 1x1} {1x2 _ _ 1x2} {_ 1x2 _ _} {1x1 _ _ 1x1} {2x1 _ 2x1 _}]
 # Super Century
-F451312111111..12bb..12........21..11....21..
-
+S:[4x5] G:[1,3] M:[F] B:[{1x2 1x1 1x1 1x1} {_ 1x2 2X2 _} {1x2 _ _ _} {_ 2x1 _ 1x1} {_ 2x1 _ _}]
 # Supercompo
-F4513..bb....11....111221..12..21....1121..11
+S:[4x5] G:[1,3] M:[F] B:[{_ 2X2 _ _} {1x1 _ _ 1x1} {1x2 2x1 _ 1x2} {_ 2x1 _ _} {1x1 2x1 _ 1x1}]

flake.nix

@@ -21,58 +21,18 @@ rec {
         };
         inherit (pkgs) lib stdenv;
 
+        windowsPkgs = import nixpkgs {
+          inherit system;
+          crossSystem = {
+            config = "x86_64-w64-mingw32";
+          };
+          config.allowUnfree = true;
+        };
+
         # ===========================================================================================
         # Define custom dependencies
         # ===========================================================================================
 
-        # raylib-cpp = stdenv.mkDerivation {
-        #   pname = "raylib-cpp";
-        #   version = "5.5.0-unstable-2025-11-12";
-        #
-        #   src = pkgs.fetchFromGitHub {
-        #     owner = "RobLoach";
-        #     repo = "raylib-cpp";
-        #     rev = "21b0d0f57a09a7f741d20b7157f440ae87f02c76";
-        #     hash = "sha256-P9x6Zc5t648gR7oYXe38PEX/a4oh4PfuVCnjT0vC10k=";
-        #   };
-        #
-        #   # autoPatchelfHook is needed for appendRunpaths
-        #   nativeBuildInputs = with pkgs; [
-        #     cmake
-        #     # autoPatchelfHook
-        #   ];
-        #
-        #   buildInputs = with pkgs; [
-        #     raylib
-        #     glfw
-        #     SDL2
-        #   ];
-        #
-        #   propagatedBuildInputs = with pkgs; [
-        #     libGLU
-        #     libx11
-        #   ];
-        #
-        #   cmakeFlags = [
-        #     "-DBUILD_RAYLIB_CPP_EXAMPLES=OFF"
-        #     "-DBUILD_TESTING=OFF"
-        #     # Point CMake to the nixpkgs raylib so it doesn't try to fetch its own
-        #     "-Draylib_DIR=${pkgs.raylib}/lib/cmake/raylib"
-        #   ];
-        # };
-
-        # raygui = pkgs.raygui.overrideAttrs (finalAttrs: prevAttrs: {
-        #   version = "4.0-unstable-2026-02-24";
-        #
-        #   src = pkgs.fetchFromGitHub {
-        #     owner = "raysan5";
-        #     repo = "raygui";
-        #     rev = "5788707b6b7000343c14653b1ad3b971ca0597e4";
-        #     hash = "sha256-wKylPeNw7wO5xuTfnp1OYETQ78EPlr4NU9erbmIFgjE=";
-        #   };
-        #
-        # });
-
         raygui = stdenv.mkDerivation (finalAttrs: {
           pname = "raygui";
           version = "4.0-unstable-2026-02-24";
@@ -148,6 +108,8 @@ rec {
           valgrind
           # gnumake
           cmake
+          ninja
+          # cling
           # pkg-config
           # clang-tools
           # compdb
@@ -157,6 +119,8 @@ rec {
           hotspot
           kdePackages.kcachegrind
           gdbgui
+          massif-visualizer
+          heaptrack
           # renderdoc
         ];
 
@@ -165,19 +129,16 @@ rec {
         # - Interpreters needed by patchShebangs for scripts which are installed, which can be the case for e.g. perl
         buildInputs = with pkgs; [
           # C/C++:
-          # boost
-          # sfml
           raylib
           raygui
-          # octree # this one doesn't store center of mass per node - which I need :(
-          tracy-wayland
           thread-pool
+          boost
+
+          # Debugging
+          tracy-wayland
           backward-cpp
           libbfd
-          # llvmPackages.openmp # not required for compilation but for clangd to find the headers
-          # raylib-cpp
-          # tinyobjloader
-          # gperftools
+          catch2_3
         ];
         # ===========================================================================================
         # Define buildable + installable packages
@@ -193,18 +154,66 @@ rec {
             cmake
           ];
 
+          cmakeFlags = [
+            "-DDISABLE_TRACY=On"
+            "-DDISABLE_BACKWARD=On"
+            "-DDISABLE_TESTS=On"
+          ];
+
+          hardeningDisable = ["all"];
+
+          preConfigure = ''
+            unset NIX_ENFORCE_NO_NATIVE
+          '';
+
           installPhase = ''
             mkdir -p $out/bin
             cp ./${pname} $out/bin/
             cp $src/default.puzzle $out/bin/
+            cp -r $src/fonts $out/bin/fonts
+            cp -r $src/shader $out/bin/shader
+          '';
+        };
+
+        windowsPackage = windowsPkgs.stdenv.mkDerivation rec {
+          pname = "masssprings";
+          version = "1.0.0";
+          src = ./.;
+
+          # nativeBuildInputs must be from the build-platform (not cross)
+          # so we use "pkgs" here, not "windowsPkgs"
+          nativeBuildInputs = with pkgs; [
+            cmake
+          ];
+
+          buildInputs = with windowsPkgs; [
+            raylib
+            raygui
+            thread-pool
+            boost
+          ];
+
+          cmakeFlags = [
+            "-DCMAKE_SYSTEM_NAME=Windows"
+            "-DDISABLE_TRACY=On"
+            "-DDISABLE_BACKWARD=On"
+          ];
+
+          installPhase = ''
+            mkdir -p $out/bin
+            cp ./${pname}.exe $out/bin/
+            cp $src/default.puzzle $out/bin/
+            cp -r $src/fonts $out/bin/fonts
+            cp -r $src/shader $out/bin/shader
           '';
         };
       in rec {
-        # Provide package for "nix build"
-        defaultPackage = package;
-        defaultApp = flake-utils.lib.mkApp {
-          drv = defaultPackage;
+        # Provide packages for "nix build" and "nix run"
+        packages = {
+          default = package;
+          windows = windowsPackage;
         };
+        apps.default = flake-utils.lib.mkApp {drv = package;};
 
         # Provide environment for "nix develop"
         devShells = {
@@ -258,9 +267,8 @@ rec {
                   cd cmake-build-${typeLower}
 
                   echo "Running cmake"
-                  cmake -G "Unix Makefiles" \
+                  cmake -G "Ninja" \
                         -DCMAKE_BUILD_TYPE="${type}" \
-                        -DUSE_TRACY=On \
                         ..
 
                   echo "Linking compile_commands.json"
@@ -298,9 +306,16 @@ rec {
                 abbr -a build-release "${buildRelease}"
                 abbr -a debug "${buildDebug} && ./cmake-build-debug/masssprings"
                 abbr -a release "${buildRelease} && ./cmake-build-release/masssprings"
+                abbr -a debug-clean "${cmakeDebug} && ${buildDebug} && ./cmake-build-debug/masssprings"
+                abbr -a release-clean "${cmakeRelease} && ${buildRelease} && ./cmake-build-release/masssprings"
+
                 abbr -a rungdb "${buildDebug} && gdb --tui ./cmake-build-debug/masssprings"
-                abbr -a runtracy "tracy -a 127.0.0.1 &; ${buildRelease} && sudo -E ./cmake-build-release/masssprings_tracy"
+                abbr -a runperf "${buildRelease} && perf record -g ./cmake-build-release/masssprings && hotspot ./perf.data"
+                abbr -a runtracy "tracy -a 127.0.0.1 &; ${buildRelease} && sudo -E ./cmake-build-release/masssprings"
                 abbr -a runvalgrind "${buildDebug} && valgrind --leak-check=full --show-reachable=no --show-leak-kinds=definite,indirect,possible --track-origins=no --suppressions=valgrind.supp --log-file=valgrind.log ./cmake-build-debug/masssprings && cat valgrind.log"
+                abbr -a runtests "${buildDebug} && ./cmake-build-debug/tests"
+
+                abbr -a runclion "clion ./CMakeLists.txt 2>/dev/null 1>&2 & disown;"
               '';
             in
               builtins.concatStringsSep "\n" [
@@ -311,7 +326,7 @@ rec {
               ];
           };
 
-          # TODO: Doesn't work
+          # TODO: Can't get renderdoc in FHS to work
 
           # FHS environment for renderdoc. Access with "nix develop .#renderdoc".
           # https://ryantm.github.io/nixpkgs/builders/special/fhs-environments

include/camera.hpp

@@ -1,30 +0,0 @@
-#ifndef __CAMERA_HPP_
-#define __CAMERA_HPP_
-
-#include "config.hpp"
-
-#include <raylib.h>
-#include <raymath.h>
-
-class OrbitCamera3D {
-public:
-  Vector3 position = Vector3Zero();
-  Vector3 target = Vector3Zero();
-  float distance = CAMERA_DISTANCE;
-  float fov = CAMERA_FOV;
-  CameraProjection projection = CAMERA_PERSPECTIVE;
-  float angle_x = 0.0;
-  float angle_y = 0.0;
-
-  Camera camera = Camera{Vector3(0, 0, -distance), target, Vector3(0, 1.0, 0),
-                         fov, projection};
-
-public:
-  auto Rotate(Vector2 last_mouse, Vector2 mouse) -> void;
-
-  auto Pan(Vector2 last_mouse, Vector2 mouse) -> void;
-
-  auto Update(const Vector3 &current_target, bool lock) -> void;
-};
-
-#endif

include/config.hpp

@@ -1,34 +1,38 @@
-#ifndef __CONFIG_HPP_
-#define __CONFIG_HPP_
+#ifndef CONFIG_HPP_
+#define CONFIG_HPP_
 
 #include <raylib.h>
 
 #define THREADPOOL // Enable physics threadpool
-#define BACKWARD   // Enable pretty stack traces
 
 // Gets set by CMake
+// #define BACKWARD   // Enable pretty stack traces
 // #define TRACY      // Enable tracy profiling support
 
 // Window
 constexpr int INITIAL_WIDTH = 600;
 constexpr int INITIAL_HEIGHT = 600;
-constexpr int MENU_HEIGHT = 350;
+constexpr int MENU_HEIGHT = 300;
+constexpr int POPUP_WIDTH = 450;
+constexpr int POPUP_HEIGHT = 150;
 
 // Menu
 constexpr int MENU_PAD = 5;
 constexpr int BUTTON_PAD = 12;
 constexpr int MENU_ROWS = 7;
 constexpr int MENU_COLS = 3;
-constexpr const char *FONT = "fonts/SpaceMono.ttf";
+constexpr const char* FONT = "fonts/SpaceMono.ttf";
 constexpr int FONT_SIZE = 26;
 
 // Camera Controls
-constexpr float CAMERA_FOV = 120.0;
+constexpr float CAMERA_FOV = 90.0;
+constexpr float FOV_SPEED = 1.0;
+constexpr float MIN_FOV = 10.0;
+constexpr float MAX_FOV = 180.0;
 constexpr float CAMERA_DISTANCE = 20.0;
+constexpr float ZOOM_SPEED = 2.5;
 constexpr float MIN_CAMERA_DISTANCE = 2.0;
 constexpr float MAX_CAMERA_DISTANCE = 2000.0;
-constexpr float ZOOM_SPEED = 2.5;
-constexpr float FOV_SPEED = 1.0;
 constexpr float ZOOM_MULTIPLIER = 4.0;
 constexpr float PAN_SPEED = 2.0;
 constexpr float PAN_MULTIPLIER = 10.0;
@@ -42,16 +46,21 @@ constexpr float SIM_SPEED = 4.0;             // How large each update should be
 constexpr float MASS = 1.0;                  // Mass spring system
 constexpr float SPRING_CONSTANT = 5.0;       // Mass spring system
 constexpr float DAMPENING_CONSTANT = 1.0;    // Mass spring system
-constexpr float REST_LENGTH = 2.0;           // Mass spring system
+constexpr float REST_LENGTH = 3.0;           // Mass spring system
 constexpr float VERLET_DAMPENING = 0.05;     // [0, 1]
-constexpr float BH_FORCE = 2.0;              // Barnes-Hut [1.0, 3.0]
-constexpr float THETA = 0.9;                 // Barnes-Hut [0.5, 1.0]
+constexpr float BH_FORCE = 2.5;              // Barnes-Hut [1.0, 3.0]
+constexpr float THETA = 0.8;                 // Barnes-Hut [0.5, 1.0]
 constexpr float SOFTENING = 0.01;            // Barnes-Hut [0.01, 1.0]
 
 // Graph Drawing
+constexpr Color EDGE_COLOR = DARKBLUE;
 constexpr float VERTEX_SIZE = 0.5;
-constexpr Color VERTEX_COLOR = GREEN;
-constexpr Color EDGE_COLOR = DARKGREEN;
+static const Color VERTEX_COLOR = Fade(BLUE, 0.5);
+constexpr Color VERTEX_VISITED_COLOR = DARKBLUE;
+constexpr Color VERTEX_PATH_COLOR = GREEN;
+constexpr Color VERTEX_TARGET_COLOR = RED;
+constexpr Color VERTEX_START_COLOR = ORANGE;
+constexpr Color VERTEX_CURRENT_COLOR = PURPLE;
 constexpr int DRAW_VERTICES_LIMIT = 1000000;
 
 // Klotski Drawing
@@ -62,6 +71,5 @@ constexpr Color BOARD_COLOR_FREE = RAYWHITE;
 constexpr Color BLOCK_COLOR = DARKBLUE;
 constexpr Color TARGET_BLOCK_COLOR = RED;
 constexpr Color WALL_COLOR = BLACK;
-constexpr Color GOAL_COLOR = ORANGE;
 
-#endif
+#endif

include/distance.hpp

@@ -1,32 +0,0 @@
-#ifndef __DISTANCE_HPP_
-#define __DISTANCE_HPP_
-
-#include "config.hpp"
-
-#include <cstddef>
-#include <vector>
-
-struct DistanceResult {
-  // distances[n] = distance from n to target
-  std::vector<int> distances;
-
-  // parents[n] = next node on the path from n to target
-  std::vector<std::size_t> parents;
-
-  // nearest_target[n] = closest target node to n
-  std::vector<std::size_t> nearest_targets;
-
-  auto Clear() -> void;
-
-  auto Empty() -> bool;
-};
-
-auto CalculateDistances(
-    std::size_t node_count,
-    const std::vector<std::pair<std::size_t, std::size_t>> &edges,
-    const std::vector<std::size_t> &targets) -> DistanceResult;
-
-auto GetPath(const DistanceResult &result, std::size_t source)
-    -> std::vector<std::size_t>;
-
-#endif

include/graph_distances.hpp

@@ -0,0 +1,24 @@
+#ifndef DISTANCE_HPP_
+#define DISTANCE_HPP_
+
+#include <cstddef>
+#include <vector>
+
+class graph_distances
+{
+public:
+    std::vector<int> distances;          // distances[n] = distance from node n to target
+    std::vector<size_t> parents;         // parents[n] = next node on the path from node n to target
+    std::vector<size_t> nearest_targets; // nearest_target[n] = closest target node to  node n
+
+public:
+    auto clear() -> void;
+    [[nodiscard]] auto empty() const -> bool;
+
+    auto calculate_distances(size_t node_count, const std::vector<std::pair<size_t, size_t>>& edges,
+                             const std::vector<size_t>& targets) -> void;
+
+    [[nodiscard]] auto get_shortest_path(size_t source) const -> std::vector<size_t>;
+};
+
+#endif

include/gui.hpp

@@ -1,190 +0,0 @@
-#ifndef __GUI_HPP_
-#define __GUI_HPP_
-
-#include "camera.hpp"
-#include "config.hpp"
-#include "input.hpp"
-#include "state.hpp"
-
-#include <raygui.h>
-#include <raylib.h>
-
-class Grid {
-public:
-  int x;
-  int y;
-  int width;
-  int height;
-  int columns;
-  int rows;
-  const int padding;
-
-public:
-  Grid(int _x, int _y, int _width, int _height, int _columns, int _rows,
-       int _padding)
-      : x(_x), y(_y), width(_width), height(_height), columns(_columns),
-        rows(_rows), padding(_padding) {}
-
-public:
-  auto UpdateBounds(int _x, int _y, int _width, int _height, int _columns,
-                    int _rows) -> void;
-
-  auto UpdateBounds(int _x, int _y, int _width, int _height) -> void;
-
-  auto UpdateBounds(int _x, int _y) -> void;
-
-  auto Bounds() const -> Rectangle;
-
-  auto Bounds(int _x, int _y, int _width, int _height) const -> Rectangle;
-
-  auto SquareBounds() const -> Rectangle;
-
-  auto SquareBounds(int _x, int _y, int _width, int _height) const -> Rectangle;
-};
-
-class Gui {
-  struct Style {
-    int border_color_normal;
-    int base_color_normal;
-    int text_color_normal;
-
-    int border_color_focused;
-    int base_color_focused;
-    int text_color_focused;
-
-    int border_color_pressed;
-    int base_color_pressed;
-    int text_color_pressed;
-
-    int border_color_disabled;
-    int base_color_disabled;
-    int text_color_disabled;
-  };
-
-  struct DefaultStyle : Style {
-    int background_color;
-    int line_color;
-
-    int text_size;
-    int text_spacing;
-    int text_line_spacing;
-    int text_alignment_vertical;
-    int text_wrap_mode;
-  };
-
-  struct ComponentStyle : Style {
-    int border_width;
-    int text_padding;
-    int text_alignment;
-  };
-
-private:
-  InputHandler &input;
-  StateManager &state;
-  const OrbitCamera3D &camera;
-
-  Grid menu_grid =
-      Grid(0, 0, GetScreenWidth(), MENU_HEIGHT, MENU_COLS, MENU_ROWS, MENU_PAD);
-
-  Grid board_grid = Grid(
-      0, MENU_HEIGHT, GetScreenWidth() / 2, GetScreenHeight() - MENU_HEIGHT,
-      state.current_state.width, state.current_state.height, BOARD_PADDING);
-
-  Grid graph_overlay_grid =
-      Grid(GetScreenWidth() / 2, MENU_HEIGHT, 200, 100, 1, 4, MENU_PAD);
-
-  bool save_window = false;
-  std::array<char, 256> preset_name = {0};
-  bool help_window = false;
-
-public:
-  Gui(InputHandler &_input, StateManager &_state, const OrbitCamera3D &_camera)
-      : input(_input), state(_state), camera(_camera) {
-    Init();
-  }
-
-  Gui(const Gui &copy) = delete;
-  Gui &operator=(const Gui &copy) = delete;
-  Gui(Gui &&move) = delete;
-  Gui &operator=(Gui &&move) = delete;
-
-private:
-  auto Init() const -> void;
-
-  auto ApplyColor(Style &style, Color color) const -> void;
-
-  auto ApplyBlockColor(Style &style, Color color) const -> void;
-
-  auto ApplyTextColor(Style &style, Color color) const -> void;
-
-  auto GetDefaultStyle() const -> DefaultStyle;
-
-  auto SetDefaultStyle(const DefaultStyle &style) const -> void;
-
-  auto GetComponentStyle(int component) const -> ComponentStyle;
-
-  auto SetComponentStyle(int component, const ComponentStyle &style) const
-      -> void;
-
-  auto DrawButton(Rectangle bounds, const std::string &label, Color color,
-                  bool enabled = true, int font_size = FONT_SIZE) const -> int;
-
-  auto DrawMenuButton(int x, int y, int width, int height,
-                      const std::string &label, Color color,
-                      bool enabled = true, int font_size = FONT_SIZE) const
-      -> int;
-
-  auto DrawToggleSlider(Rectangle bounds, const std::string &off_label,
-                        const std::string &on_label, int *active, Color color,
-                        bool enabled = true, int font_size = FONT_SIZE) const
-      -> int;
-
-  auto DrawMenuToggleSlider(int x, int y, int width, int height,
-                            const std::string &off_label,
-                            const std::string &on_label, int *active,
-                            Color color, bool enabled = true,
-                            int font_size = FONT_SIZE) const -> int;
-
-  auto DrawSpinner(Rectangle bounds, const std::string &label, int *value,
-                   int min, int max, Color color, bool enabled = true,
-                   int font_size = FONT_SIZE) const -> int;
-
-  auto DrawMenuSpinner(int x, int y, int width, int height,
-                       const std::string &label, int *value, int min, int max,
-                       Color color, bool enabled = true,
-                       int font_size = FONT_SIZE) const -> int;
-
-  auto DrawLabel(Rectangle bounds, const std::string &text, Color color,
-                 bool enabled = true, int font_size = FONT_SIZE) const -> int;
-
-  auto DrawBoardBlock(int x, int y, int width, int height, Color color,
-                      bool enabled = true) const -> bool;
-
-  auto WindowOpen() const -> bool;
-
-  // Different menu sections
-  auto DrawMenuHeader(Color color) const -> void;
-  auto DrawGraphInfo(Color color) const -> void;
-  auto DrawGraphControls(Color color) const -> void;
-  auto DrawCameraControls(Color color) const -> void;
-  auto DrawPuzzleControls(Color color) const -> void;
-  auto DrawEditControls(Color color) const -> void;
-  auto DrawMenuFooter(Color color) -> void;
-
-public:
-  auto GetBackgroundColor() const -> Color;
-
-  auto HelpPopup() -> void;
-
-  auto DrawSavePresetPopup() -> void;
-
-  auto DrawMainMenu() -> void;
-
-  auto DrawPuzzleBoard() -> void;
-
-  auto DrawGraphOverlay(int fps, int ups) -> void;
-
-  auto Update() -> void;
-};
-
-#endif

include/input.hpp

@@ -1,156 +0,0 @@
-#ifndef __INPUT_HPP_
-#define __INPUT_HPP_
-
-#include "camera.hpp"
-#include "config.hpp"
-#include "state.hpp"
-
-#include <functional>
-#include <raylib.h>
-#include <raymath.h>
-
-class InputHandler {
-  struct GenericHandler {
-    std::function<void(InputHandler &)> handler;
-  };
-
-  struct MouseHandler : GenericHandler {
-    MouseButton button;
-  };
-
-  struct KeyboardHandler : GenericHandler {
-    KeyboardKey key;
-  };
-
-private:
-  std::vector<GenericHandler> generic_handlers;
-  std::vector<MouseHandler> mouse_pressed_handlers;
-  std::vector<MouseHandler> mouse_released_handlers;
-  std::vector<KeyboardHandler> key_pressed_handlers;
-  std::vector<KeyboardHandler> key_released_handlers;
-
-public:
-  StateManager &state;
-  OrbitCamera3D &camera;
-
-  bool disable = false;
-
-  // Block selection
-  int hov_x = -1;
-  int hov_y = -1;
-  int sel_x = 0;
-  int sel_y = 0;
-
-  // Editing
-  bool editing = false;
-  bool has_block_add_xy = false;
-  int block_add_x = -1;
-  int block_add_y = -1;
-
-  // Graph display
-  bool mark_path = false;
-  bool mark_solutions = false;
-  bool connect_solutions = false;
-
-  // Camera
-  bool camera_lock = true;
-  bool camera_panning = false;
-  bool camera_rotating = false;
-
-  // Mouse dragging
-  Vector2 mouse = Vector2Zero();
-  Vector2 last_mouse = Vector2Zero();
-
-public:
-  InputHandler(StateManager &_state, OrbitCamera3D &_camera)
-      : state(_state), camera(_camera) {
-    InitHandlers();
-  }
-
-  InputHandler(const InputHandler &copy) = delete;
-  InputHandler &operator=(const InputHandler &copy) = delete;
-  InputHandler(InputHandler &&move) = delete;
-  InputHandler &operator=(InputHandler &&move) = delete;
-
-  ~InputHandler() {}
-
-private:
-  auto InitHandlers() -> void;
-
-public:
-  // Helpers
-  auto MouseInMenuPane() -> bool;
-  auto MouseInBoardPane() -> bool;
-  auto MouseInGraphPane() -> bool;
-
-  // Mouse actions
-  auto MouseHover() -> void;
-  auto CameraStartPan() -> void;
-  auto CameraPan() -> void;
-  auto CameraStopPan() -> void;
-  auto CameraStartRotate() -> void;
-  auto CameraRotate() -> void;
-  auto CameraStopRotate() -> void;
-  auto CameraZoom() -> void;
-  auto CameraFov() -> void;
-  auto SelectBlock() -> void;
-  auto StartAddBlock() -> void;
-  auto ClearAddBlock() -> void;
-  auto AddBlock() -> void;
-  auto RemoveBlock() -> void;
-  auto PlaceGoal() -> void;
-
-  // Key actions
-  auto ToggleCameraLock() -> void;
-  auto ToggleCameraProjection() -> void;
-  auto MoveBlockNor() -> void;
-  auto MoveBlockWes() -> void;
-  auto MoveBlockSou() -> void;
-  auto MoveBlockEas() -> void;
-  auto PrintState() const -> void;
-  auto PreviousPreset() -> void;
-  auto NextPreset() -> void;
-  auto ResetState() -> void;
-  auto FillGraph() -> void;
-  auto ClearGraph() -> void;
-  auto ToggleMarkSolutions() -> void;
-  auto ToggleConnectSolutions() -> void;
-  auto ToggleMarkPath() -> void;
-  auto MakeOptimalMove() -> void;
-  auto GoToWorstState() -> void;
-  auto GoToNearestTarget() -> void;
-  auto UndoLastMove() -> void;
-  auto ToggleRestrictedMovement() -> void;
-  auto ToggleTargetBlock() -> void;
-  auto ToggleWallBlock() -> void;
-  auto RemoveBoardColumn() -> void;
-  auto AddBoardColumn() -> void;
-  auto RemoveBoardRow() -> void;
-  auto AddBoardRow() -> void;
-  auto ToggleEditing() -> void;
-  auto ClearGoal() -> void;
-
-  // General
-  auto RegisterGenericHandler(std::function<void(InputHandler &)> handler)
-      -> void;
-
-  auto RegisterMousePressedHandler(MouseButton button,
-                                   std::function<void(InputHandler &)> handler)
-      -> void;
-
-  auto RegisterMouseReleasedHandler(MouseButton button,
-                                    std::function<void(InputHandler &)> handler)
-      -> void;
-
-  auto RegisterKeyPressedHandler(KeyboardKey key,
-                                 std::function<void(InputHandler &)> handler)
-      -> void;
-
-  auto RegisterKeyReleasedHandler(KeyboardKey key,
-                                  std::function<void(InputHandler &)> handler)
-      -> void;
-
-  auto HandleInput() -> void;
-};
-
-#endif

include/input_handler.hpp

@@ -0,0 +1,177 @@
+#ifndef INPUT_HPP_
+#define INPUT_HPP_
+
+#include "orbit_camera.hpp"
+#include "state_manager.hpp"
+
+#include <functional>
+#include <queue>
+#include <raylib.h>
+#include <raymath.h>
+
+struct show_ok_message
+{
+    std::string title;
+    std::string message;
+};
+
+struct show_yes_no_message
+{
+    std::string title;
+    std::string message;
+    std::function<void()> on_yes;
+};
+
+struct show_save_preset_window
+{};
+
+using ui_command = std::variant<show_ok_message, show_yes_no_message, show_save_preset_window>;
+
+class input_handler
+{
+    struct generic_handler
+    {
+        std::function<void(input_handler&)> handler;
+    };
+
+    struct mouse_handler : generic_handler
+    {
+        MouseButton button;
+    };
+
+    struct keyboard_handler : generic_handler
+    {
+        KeyboardKey key;
+    };
+
+private:
+    std::vector<generic_handler> generic_handlers;
+    std::vector<mouse_handler> mouse_pressed_handlers;
+    std::vector<mouse_handler> mouse_released_handlers;
+    std::vector<keyboard_handler> key_pressed_handlers;
+    std::vector<keyboard_handler> key_released_handlers;
+
+public:
+    state_manager& state;
+    orbit_camera& camera;
+
+    std::queue<ui_command> ui_commands;
+
+    bool disable = false;
+
+    // Block selection
+    int hov_x = -1;
+    int hov_y = -1;
+    int sel_x = 0;
+    int sel_y = 0;
+
+    // Editing
+    bool editing = false;
+    bool has_block_add_xy = false;
+    int block_add_x = -1;
+    int block_add_y = -1;
+
+    // Graph display
+    bool mark_path = false;
+    bool mark_solutions = false;
+    bool connect_solutions = false;
+
+    // Camera
+    bool camera_lock = true;
+    bool camera_mass_center_lock = false;
+    bool camera_panning = false;
+    bool camera_rotating = false;
+
+    // Mouse dragging
+    Vector2 mouse = Vector2Zero();
+    Vector2 last_mouse = Vector2Zero();
+
+public:
+    input_handler(state_manager& _state, orbit_camera& _camera) : state(_state), camera(_camera)
+    {
+        init_handlers();
+    }
+
+    input_handler(const input_handler& copy) = delete;
+    auto operator=(const input_handler& copy) -> input_handler& = delete;
+    input_handler(input_handler&& move) = delete;
+    auto operator=(input_handler&& move) -> input_handler& = delete;
+
+private:
+    auto init_handlers() -> void;
+
+public:
+    // Helpers
+    [[nodiscard]] auto mouse_in_menu_pane() const -> bool;
+    [[nodiscard]] auto mouse_in_board_pane() const -> bool;
+    [[nodiscard]] auto mouse_in_graph_pane() const -> bool;
+
+    // Mouse actions
+    auto mouse_hover() -> void;
+    auto camera_start_pan() -> void;
+    auto camera_pan() const -> void;
+    auto camera_stop_pan() -> void;
+    auto camera_start_rotate() -> void;
+    auto camera_rotate() const -> void;
+    auto camera_stop_rotate() -> void;
+    auto camera_zoom() const -> void;
+    auto camera_fov() const -> void;
+    auto select_block() -> void;
+    auto start_add_block() -> void;
+    auto clear_add_block() -> void;
+    auto add_block() -> void;
+    auto remove_block() -> void;
+    auto place_goal() const -> void;
+
+    // Key actions
+    auto toggle_camera_lock() -> void;
+    auto toggle_camera_mass_center_lock() -> void;
+    auto toggle_camera_projection() const -> void;
+    auto move_block_nor() -> void;
+    auto move_block_wes() -> void;
+    auto move_block_sou() -> void;
+    auto move_block_eas() -> void;
+    auto print_state() const -> void;
+    auto load_previous_preset() -> void;
+    auto load_next_preset() -> void;
+    auto goto_starting_state() -> void;
+    auto populate_graph() const -> void;
+    auto clear_graph() -> void;
+    auto toggle_mark_solutions() -> void;
+    auto toggle_connect_solutions() -> void;
+    auto toggle_mark_path() -> void;
+    auto goto_optimal_next_state() const -> void;
+    auto goto_most_distant_state() const -> void;
+    auto goto_closest_target_state() const -> void;
+    auto goto_previous_state() const -> void;
+    auto toggle_restricted_movement() const -> void;
+    auto toggle_target_block() const -> void;
+    auto toggle_wall_block() const -> void;
+    auto remove_board_column() const -> void;
+    auto add_board_column() const -> void;
+    auto remove_board_row() const -> void;
+    auto add_board_row() const -> void;
+    auto toggle_editing() -> void;
+    auto clear_goal() const -> void;
+    auto save_preset() -> void;
+
+    // General
+    auto register_generic_handler(const std::function<void(input_handler&)>& handler) -> void;
+
+    auto register_mouse_pressed_handler(MouseButton button,
+                                        const std::function<void(input_handler&)>& handler) -> void;
+
+    auto register_mouse_released_handler(MouseButton button,
+                                         const std::function<void(input_handler&)>& handler)
+        -> void;
+
+    auto register_key_pressed_handler(KeyboardKey key,
+                                      const std::function<void(input_handler&)>& handler) -> void;
+
+    auto register_key_released_handler(KeyboardKey key,
+                                       const std::function<void(input_handler&)>& handler) -> void;
+
+    auto handle_input() -> void;
+};
+
+#endif

include/mass_spring_system.hpp

@@ -0,0 +1,114 @@
+#ifndef MASS_SPRING_SYSTEM_HPP_
+#define MASS_SPRING_SYSTEM_HPP_
+
+#include "octree.hpp"
+#include "util.hpp"
+#include "config.hpp"
+
+#include <raylib.h>
+#include <raymath.h>
+
+#ifdef THREADPOOL
+#if defined(_WIN32)
+#define NOGDI  // All GDI defines and routines
+#define NOUSER // All USER defines and routines
+#endif
+#define BS_THREAD_POOL_NATIVE_EXTENSIONS
+#include <BS_thread_pool.hpp>
+#if defined(_WIN32) // raylib uses these names as function parameters
+#undef near
+#undef far
+#endif
+#endif
+
+class mass_spring_system
+{
+public:
+    class mass
+    {
+    public:
+        Vector3 position = Vector3Zero();
+        Vector3 previous_position = Vector3Zero(); // for verlet integration
+        Vector3 velocity = Vector3Zero();
+        Vector3 force = Vector3Zero();
+
+    public:
+        mass() = delete;
+
+        explicit mass(const Vector3 _position)
+            : position(_position), previous_position(_position) {}
+
+    public:
+        auto clear_force() -> void;
+        auto calculate_velocity(float delta_time) -> void;
+        auto calculate_position(float delta_time) -> void;
+        auto verlet_update(float delta_time) -> void;
+    };
+
+    class spring
+    {
+    public:
+        size_t a;
+        size_t b;
+
+    public:
+        spring(const size_t _a, const size_t _b)
+            : a(_a), b(_b) {}
+
+    public:
+        static auto calculate_spring_force(mass& _a, mass& _b) -> void;
+    };
+
+private:
+    #ifdef THREADPOOL
+    BS::thread_pool<> threads;
+    #endif
+
+public:
+    octree tree;
+
+    // This is the main ownership of all the states/masses/springs.
+    std::vector<mass> masses;
+    std::vector<spring> springs;
+
+public:
+    mass_spring_system()
+    #ifdef THREADPOOL
+        : threads(std::thread::hardware_concurrency() - 1, set_thread_name)
+    #endif
+    {
+        infoln("Using Barnes-Hut + Octree repulsion force calculation.");
+
+        #ifdef THREADPOOL
+        infoln("Thread-pool: {} threads.", threads.get_thread_count());
+        #else
+        infoln("Thread-pool: Disabled.");
+        #endif
+    }
+
+    mass_spring_system(const mass_spring_system& copy) = delete;
+    auto operator=(const mass_spring_system& copy) -> mass_spring_system& = delete;
+    mass_spring_system(mass_spring_system& move) = delete;
+    auto operator=(mass_spring_system&& move) -> mass_spring_system& = delete;
+
+private:
+    #ifdef THREADPOOL
+    static auto set_thread_name(size_t idx) -> void;
+    #endif
+
+    auto build_octree() -> void;
+
+public:
+    auto clear() -> void;
+    auto add_mass() -> void;
+    auto add_spring(size_t a, size_t b) -> void;
+
+    auto clear_forces() -> void;
+    auto calculate_spring_forces() -> void;
+    auto calculate_repulsion_forces() -> void;
+    auto verlet_update(float delta_time) -> void;
+
+    auto center_masses() -> void;
+};
+
+#endif

include/octree.hpp

@@ -1,54 +1,52 @@
-#ifndef __OCTREE_HPP_
-#define __OCTREE_HPP_
-
-#include "config.hpp"
+#ifndef OCTREE_HPP_
+#define OCTREE_HPP_
 
+#include <array>
 #include <raylib.h>
 #include <raymath.h>
 #include <vector>
 
-class OctreeNode {
-public:
-  Vector3 mass_center;
-  float mass_total;
-  Vector3 box_min; // area start
-  Vector3 box_max; // area end
-  int children[8];
-  int mass_id;
-  bool leaf;
+class octree
+{
+    class node
+    {
+    public:
+        Vector3 mass_center = Vector3Zero();
+        float mass_total = 0.0;
+        Vector3 box_min = Vector3Zero(); // area start
+        Vector3 box_max = Vector3Zero(); // area end
+        std::array<int, 8> children = {-1, -1, -1, -1, -1, -1, -1, -1};
+        int mass_id = -1;
+        bool leaf = true;
+
+    public:
+        [[nodiscard]] auto child_count() const -> int;
+    };
 
 public:
-  OctreeNode()
-      : mass_center(Vector3Zero()), mass_total(0.0),
-        children(-1, -1, -1, -1, -1, -1, -1, -1), mass_id(-1), leaf(true) {}
+    static constexpr int MAX_DEPTH = 20;
+
+    std::vector<node> nodes;
 
 public:
-  auto ChildCount() const -> int;
-};
+    octree() = default;
 
-class Octree {
-public:
-  std::vector<OctreeNode> nodes;
+    octree(const octree& copy) = delete;
+    auto operator=(const octree& copy) -> octree& = delete;
+    octree(octree&& move) = delete;
+    auto operator=(octree&& move) -> octree& = delete;
 
 public:
-  Octree() {}
+    auto create_empty_leaf(const Vector3& box_min, const Vector3& box_max) -> int;
 
-  Octree(const Octree &copy) = delete;
-  Octree &operator=(const Octree &copy) = delete;
-  Octree(Octree &&move) = delete;
-  Octree &operator=(Octree &&move) = delete;
+    [[nodiscard]] auto get_octant(int node_idx, const Vector3& pos) const -> int;
 
-public:
-  auto CreateNode(const Vector3 &box_min, const Vector3 &box_max) -> int;
+    [[nodiscard]] auto get_child_bounds(int node_idx, int octant) const
+        -> std::pair<Vector3, Vector3>;
 
-  auto GetOctant(int node_idx, const Vector3 &pos) -> int;
+    auto insert(int node_idx, int mass_id, const Vector3& pos, float mass, int depth) -> void;
 
-  auto GetChildBounds(int node_idx, int octant) -> std::pair<Vector3, Vector3>;
-
-  auto Insert(int node_idx, int mass_id, const Vector3 &pos, float mass)
-      -> void;
-
-  auto CalculateForce(int node_idx, const Vector3 &pos) const -> Vector3;
+    [[nodiscard]] auto calculate_force(int node_idx, const Vector3& pos) const -> Vector3;
 };
 
 #endif

include/orbit_camera.hpp

@@ -0,0 +1,31 @@
+#ifndef CAMERA_HPP_
+#define CAMERA_HPP_
+
+#include "config.hpp"
+
+#include <raylib.h>
+#include <raymath.h>
+
+class orbit_camera
+{
+public:
+    Vector3 position = Vector3Zero();
+    Vector3 target = Vector3Zero();
+    float distance = CAMERA_DISTANCE;
+    float fov = CAMERA_FOV;
+    CameraProjection projection = CAMERA_PERSPECTIVE;
+    float angle_x = 0.0;
+    float angle_y = 0.0;
+
+    Camera camera = Camera{Vector3(0, 0, -distance), target, Vector3(0, 1.0, 0), fov, projection};
+
+public:
+    auto rotate(Vector2 last_mouse, Vector2 mouse) -> void;
+
+    auto pan(Vector2 last_mouse, Vector2 mouse) -> void;
+
+    auto update(const Vector3& current_target, const Vector3& mass_center, bool lock,
+                bool mass_center_lock) -> void;
+};
+
+#endif

include/physics.hpp

@@ -1,190 +0,0 @@
-#ifndef __PHYSICS_HPP_
-#define __PHYSICS_HPP_
-
-#include "config.hpp"
-#include "octree.hpp"
-
-#include <atomic>
-#include <condition_variable>
-#include <cstddef>
-#include <mutex>
-#include <print>
-#include <queue>
-#include <raylib.h>
-#include <raymath.h>
-#include <thread>
-#include <variant>
-#include <vector>
-
-#ifdef THREADPOOL
-#define BS_THREAD_POOL_NATIVE_EXTENSIONS
-#include <BS_thread_pool.hpp>
-#endif
-
-#ifdef TRACY
-#include <tracy/Tracy.hpp>
-#endif
-
-class Mass {
-public:
-  Vector3 position;
-  Vector3 previous_position; // for verlet integration
-  Vector3 velocity;
-  Vector3 force;
-
-public:
-  Mass(Vector3 _position)
-      : position(_position), previous_position(_position),
-        velocity(Vector3Zero()), force(Vector3Zero()) {}
-
-public:
-  auto ClearForce() -> void;
-
-  auto CalculateVelocity(const float delta_time) -> void;
-
-  auto CalculatePosition(const float delta_time) -> void;
-
-  auto VerletUpdate(const float delta_time) -> void;
-};
-
-class Spring {
-public:
-  std::size_t a;
-  std::size_t b;
-
-public:
-  Spring(std::size_t _a, std::size_t _b) : a(_a), b(_b) {}
-
-public:
-  auto CalculateSpringForce(Mass &_a, Mass &_b) const -> void;
-};
-
-class MassSpringSystem {
-private:
-  Octree octree;
-
-#ifdef THREADPOOL
-  BS::thread_pool<BS::tp::none> threads;
-#endif
-
-public:
-  // This is the main ownership of all the states/masses/springs.
-  std::vector<Mass> masses;
-  std::vector<Spring> springs;
-
-public:
-  MassSpringSystem()
-#ifdef THREADPOOL
-      : threads(std::thread::hardware_concurrency() - 1, SetThreadName)
-#endif
-  {
-    std::println("Using Barnes-Hut + Octree repulsion force calculation.");
-
-#ifdef THREADPOOL
-    std::println("Thread-pool: {} threads.", threads.get_thread_count());
-#endif
-  };
-
-  MassSpringSystem(const MassSpringSystem &copy) = delete;
-  MassSpringSystem &operator=(const MassSpringSystem &copy) = delete;
-  MassSpringSystem(MassSpringSystem &move) = delete;
-  MassSpringSystem &operator=(MassSpringSystem &&move) = delete;
-
-private:
-#ifdef THREADPOOL
-  static auto SetThreadName(std::size_t idx) -> void;
-#endif
-
-  auto BuildOctree() -> void;
-
-public:
-  auto AddMass() -> void;
-
-  auto AddSpring(int a, int b) -> void;
-
-  auto Clear() -> void;
-
-  auto ClearForces() -> void;
-
-  auto CalculateSpringForces() -> void;
-
-  auto CalculateRepulsionForces() -> void;
-
-  auto VerletUpdate(float delta_time) -> void;
-};
-
-class ThreadedPhysics {
-  struct AddMass {};
-  struct AddSpring {
-    std::size_t a;
-    std::size_t b;
-  };
-  struct ClearGraph {};
-
-  using Command = std::variant<AddMass, AddSpring, ClearGraph>;
-
-  struct PhysicsState {
-#ifdef TRACY
-    TracyLockable(std::mutex, command_mtx);
-#else
-    std::mutex command_mtx;
-#endif
-    std::queue<Command> pending_commands;
-
-#ifdef TRACY
-    TracyLockable(std::mutex, data_mtx);
-#else
-    std::mutex data_mtx;
-#endif
-    std::condition_variable_any data_ready_cnd;
-    std::condition_variable_any data_consumed_cnd;
-    unsigned int ups = 0;
-    std::vector<Vector3> masses; // Read by renderer
-    bool data_ready = false;
-    bool data_consumed = true;
-
-    std::atomic<bool> running{true};
-  };
-
-private:
-  std::thread physics;
-
-public:
-  PhysicsState state;
-
-public:
-  ThreadedPhysics() : physics(PhysicsThread, std::ref(state)) {}
-
-  ThreadedPhysics(const ThreadedPhysics &copy) = delete;
-  ThreadedPhysics &operator=(const ThreadedPhysics &copy) = delete;
-  ThreadedPhysics(ThreadedPhysics &&move) = delete;
-  ThreadedPhysics &operator=(ThreadedPhysics &&move) = delete;
-
-  ~ThreadedPhysics() {
-    state.running = false;
-    state.data_ready_cnd.notify_all();
-    state.data_consumed_cnd.notify_all();
-    physics.join();
-  }
-
-private:
-  static auto PhysicsThread(PhysicsState &state) -> void;
-
-public:
-  auto AddMassCmd() -> void;
-
-  auto AddSpringCmd(std::size_t a, std::size_t b) -> void;
-
-  auto ClearCmd() -> void;
-
-  auto AddMassSpringsCmd(
-      std::size_t num_masses,
-      const std::vector<std::pair<std::size_t, std::size_t>> &springs) -> void;
-};
-
-// https://en.cppreference.com/w/cpp/utility/variant/visit
-template <class... Ts> struct overloads : Ts... {
-  using Ts::operator()...;
-};
-
-#endif

include/puzzle.hpp

@@ -1,313 +1,482 @@
-#ifndef __PUZZLE_HPP_
-#define __PUZZLE_HPP_
+#ifndef PUZZLE_HPP_
+#define PUZZLE_HPP_
 
-#include "config.hpp"
+#include "util.hpp"
 
 #include <array>
 #include <cstddef>
 #include <format>
 #include <functional>
-#include <print>
+#include <ranges>
 #include <string>
 #include <vector>
+#include <bits/fs_fwd.h>
 
-enum Direction {
-  NOR = 1 << 0,
-  EAS = 1 << 1,
-  SOU = 1 << 2,
-  WES = 1 << 3,
-};
-
-// A block is represented as a 2-digit string "wh", where w is the block width
-// and h the block height.
-// The target block (to remove from the board) is represented as a 2-letter
-// lower-case string "xy", where x is the block width and y the block height and
-// width/height are represented by [abcdefghi] (~= [123456789]).
-// Immovable blocks are represented as a 2-letter upper-case string "XY", where
-// X is the block width and Y the block height and width/height are represented
-// by [ABCDEFGHI] (~= [123456789]).
-class Block {
+/*
+ * 8x8 board
+ *  -> 64 (sizes) * 2 (target) * 2 (movable) blocks = 1 Byte
+ *
+ * 1. Encode the position inside the board (max 64 cells)
+ *     -> 64 (slots) * 1 Byte (block) = 64 Byte
+ * 2. Encode the position inside the block (max 64 cells)
+ *     -> 64 (blocks) * 2 Byte (size + pos) = 128 Byte
+ * 3. Encode the position inside the block (with 15 block limit)
+ *     -> 15 (blocks) * 2 (block) = 30 Byte
+ *
+ * Store board size + restricted: +1 Byte
+ * Store target position: +1 Byte
+ *
+ * => Limit to 15 blocks max and use option 3. (4x uint64_t)
+ *
+ */
+class puzzle
+{
 public:
-  int x;
-  int y;
-  int width;
-  int height;
-  bool target;
-  bool immovable;
+    /*
+     * A block is represented as uint16_t.
+     * It stores its position, width, height and if it's the target block or immovable.
+     */
+    class block
+    {
+        friend class puzzle;
+
+    private:
+        static constexpr uint16_t INVALID = 0x8000;
+
+        static constexpr uint8_t IMMOVABLE_S = 0;
+        static constexpr uint8_t IMMOVABLE_E = 0;
+        static constexpr uint8_t TARGET_S = 1;
+        static constexpr uint8_t TARGET_E = 1;
+        static constexpr uint8_t WIDTH_S = 2;
+        static constexpr uint8_t WIDTH_E = 4;
+        static constexpr uint8_t HEIGHT_S = 5;
+        static constexpr uint8_t HEIGHT_E = 7;
+        static constexpr uint8_t X_S = 8;
+        static constexpr uint8_t X_E = 10;
+        static constexpr uint8_t Y_S = 11;
+        static constexpr uint8_t Y_E = 13;
+
+        /*
+         * Memory layout:
+         *
+         * 154 321 098 765 432 1 0
+         *  B0 YYY XXX HHH WWW T I
+         *  ---------- -----------
+         *    Byte 1     Byte 0
+         *
+         * Store the y-position at the most significant bits to obtain a row-major ordering when comparing reprs.
+         * The block at (0, 0) will be the smallest, the block at (width, height) the largest,
+         * the block at (1, 0) will be smaller than the block at (0, 1), all independent of block size.
+         * Then, the block with size (1, 1) will be smaller than the block with size (2, 2),
+         * the block with size (1, 0) - horizontal - will be smaller than the block with size (0, 1) - vertical.
+         *
+         * To mark if a block is empty, the first B bit is set to 1. This is required,
+         * since otherwise uint16_t{0} would be a valid block. This also makes empty blocks sorted last.
+         */
+        uint16_t repr;
+
+    public:
+        // Produces an invalid block, for usage with std::array<block, MaxBlocks>
+        block()
+            : repr(INVALID) {}
+
+        explicit block(const uint16_t _repr)
+            : repr(_repr) {}
+
+        block(const int x, const int y, const int w, const int h, const bool t = false, const bool i = false)
+            : repr(create_repr(x, y, w, h, t, i))
+        {
+            if (x < 0 || x + w > MAX_WIDTH || y < 0 || y + h > MAX_HEIGHT) {
+                throw std::invalid_argument("Block size out of bounds");
+            }
+            if (t && i) {
+                throw std::invalid_argument("Target block can't be immovable");
+            }
+        }
+
+        auto operator==(const block other) const -> bool
+        {
+            return repr == other.repr;
+        }
+
+        auto operator!=(const block other) const -> bool
+        {
+            return repr != other.repr;
+        }
+
+        auto operator<(const block other) const -> bool
+        {
+            return repr < other.repr;
+        }
+
+        auto operator<=(const block other) const -> bool
+        {
+            return repr <= other.repr;
+        }
+
+        auto operator>(const block other) const -> bool
+        {
+            return repr > other.repr;
+        }
+
+        auto operator>=(const block other) const -> bool
+        {
+            return repr >= other.repr;
+        }
+
+    private:
+        [[nodiscard]] static auto create_repr(uint8_t x, uint8_t y, uint8_t w, uint8_t h, bool t = false,
+                                              bool i = false) -> uint16_t;
+
+        // Repr setters
+        [[nodiscard]] auto set_x(uint8_t x) const -> block;
+        [[nodiscard]] auto set_y(uint8_t y) const -> block;
+        [[nodiscard]] auto set_width(uint8_t width) const -> block;
+        [[nodiscard]] auto set_height(uint8_t height) const -> block;
+        [[nodiscard]] auto set_target(bool target) const -> block;
+        [[nodiscard]] auto set_immovable(bool immovable) const -> block;
+
+    public:
+        [[nodiscard]] auto unpack_repr() const -> std::tuple<uint8_t, uint8_t, uint8_t, uint8_t, bool, bool>;
+
+        // Repr getters
+        [[nodiscard]] auto get_x() const -> uint8_t;
+        [[nodiscard]] auto get_y() const -> uint8_t;
+        [[nodiscard]] auto get_width() const -> uint8_t;
+        [[nodiscard]] auto get_height() const -> uint8_t;
+        [[nodiscard]] auto get_target() const -> bool;
+        [[nodiscard]] auto get_immovable() const -> bool;
+
+        // Util
+        [[nodiscard]] auto valid() const -> bool;
+        [[nodiscard]] auto principal_dirs() const -> uint8_t;
+        [[nodiscard]] auto covers(int _x, int _y) const -> bool;
+        [[nodiscard]] auto collides(block b) const -> bool;
+    };
 
 public:
-  Block(int _x, int _y, int _width, int _height, bool _target, bool _immovable)
-      : x(_x), y(_y), width(_width), height(_height), target(_target),
-        immovable(_immovable) {
-    if (_x < 0 || _x + _width >= 10 || _y < 0 || _y + _height >= 10) {
-      std::println("Block must fit in a 9x9 board!");
-      exit(1);
-    }
-  }
+    static constexpr uint8_t MAX_BLOCKS = 15;
+    static constexpr uint8_t MIN_WIDTH = 3;
+    static constexpr uint8_t MIN_HEIGHT = 3;
+    static constexpr uint8_t MAX_WIDTH = 8;
+    static constexpr uint8_t MAX_HEIGHT = 8;
 
-  Block(int _x, int _y, int _width, int _height, bool _target)
-      : Block(_x, _y, _width, _height, _target, false) {}
+private:
+    static constexpr uint16_t INVALID = 0x8000;
 
-  Block(int _x, int _y, std::string block) : x(_x), y(_y) {
-    if (block == "..") {
-      this->x = 0;
-      this->y = 0;
-      width = 0;
-      height = 0;
-      target = false;
-      return;
-    }
+    static constexpr uint8_t RESTRICTED_S = 0;
+    static constexpr uint8_t RESTRICTED_E = 0;
+    static constexpr uint8_t GOAL_X_S = 1;
+    static constexpr uint8_t GOAL_X_E = 3;
+    static constexpr uint8_t GOAL_Y_S = 4;
+    static constexpr uint8_t GOAL_Y_E = 6;
+    static constexpr uint8_t WIDTH_S = 7;
+    static constexpr uint8_t WIDTH_E = 9;
+    static constexpr uint8_t HEIGHT_S = 10;
+    static constexpr uint8_t HEIGHT_E = 12;
+    static constexpr uint8_t GOAL_S = 13;
+    static constexpr uint8_t GOAL_E = 13;
 
-    const std::array<char, 9> target_chars{'a', 'b', 'c', 'd', 'e',
-                                           'f', 'g', 'h', 'i'};
+    struct repr_cooked
+    {
+        /*
+         * Memory layout:
+         *
+         * 1543 210 98 7 654 321 0
+         *  B0G HHH WW W YYY XXX R
+         *  ---------- -----------
+         *    Byte 1     Byte 0
+         *
+         * To mark if a puzzle is empty, the first B bit is set to 1.
+         * An extra bit is used to mark if the board has a goal, because we can't store MAX_WIDTH=8 in 3 bits.
+         */
+        uint16_t meta;
 
-    target = false;
-    for (const char c : target_chars) {
-      if (block.contains(c)) {
-        target = true;
-        break;
-      }
-    }
+        // NOTE: For the hashes to work, this array needs to be sorted always.
+        // NOTE: This array might contain empty blocks at the end. The iterator handles this.
+        std::array<uint16_t, MAX_BLOCKS> blocks;
 
-    const std::array<char, 9> immovable_chars{'A', 'B', 'C', 'D', 'E',
-                                              'F', 'G', 'H', 'I'};
+        // repr_cooked() = delete;
+        // repr_cooked(const repr_cooked& copy) = delete;
+        // repr_cooked(repr_cooked&& move) = delete;
+    } __attribute__((packed));
 
-    immovable = false;
-    for (const char c : immovable_chars) {
-      if (block.contains(c)) {
-        immovable = true;
-        break;
-      }
-    }
+    /**
+     * With gcc, were allowed to acces the members arbitrarily, even if they're not active (not the ones last written):
+     * - https://gcc.gnu.org/onlinedocs/gcc-4.7.1/gcc/Structures-unions-enumerations-and-bit_002dfields-implementation.html#Structures-unions-enumerations-and-bit_002dfields-implementation
+     * - https://gcc.gnu.org/onlinedocs/gcc-4.7.1/gcc/Optimize-Options.html#Type_002dpunning
+     */
+    union repr_u
+    {
+        // The representation split into meta information and the blocks array
+        repr_cooked cooked;
 
-    if (target) {
-      width = static_cast<int>(block.at(0)) - static_cast<int>('a') + 1;
-      height = static_cast<int>(block.at(1)) - static_cast<int>('a') + 1;
-    } else if (immovable) {
-      width = static_cast<int>(block.at(0)) - static_cast<int>('A') + 1;
-      height = static_cast<int>(block.at(1)) - static_cast<int>('A') + 1;
-    } else {
-      width = std::stoi(block.substr(0, 1));
-      height = std::stoi(block.substr(1, 1));
-    }
+        // For 15 blocks, we have sizeof(meta) + blocks.size() * sizeof(block) = 2 + 15 * 2 = 32 Bytes
+        std::array<uint64_t, 4> raw;
+    };
 
-    if (_x < 0 || _x + width >= 10 || _y < 0 || _y + height >= 10) {
-      std::println("Block must fit in a 9x9 board!");
-      exit(1);
-    }
-    if (block.length() != 2) {
-      std::println("Block representation must have length 2!");
-      exit(1);
-    }
-  }
-
-  bool operator==(const Block &other) {
-    return x == other.x && y == other.y && width && other.width &&
-           target == other.target && immovable == other.immovable;
-  }
-
-  bool operator!=(const Block &other) { return !(*this == other); }
+    repr_u repr;
 
 public:
-  auto Hash() const -> std::size_t;
+    // Produces an invalid puzzle, for usage with containers
+    puzzle()
+        : repr(repr_cooked{INVALID, invalid_blocks()}) {}
 
-  static auto Invalid() -> Block;
+    explicit puzzle(const uint16_t meta)
+        : repr(repr_cooked{meta, invalid_blocks()}) {}
 
-  auto IsValid() const -> bool;
+    // NOTE: This constructor does not sort the blocks and is only for state space generation
+    puzzle(const std::tuple<uint8_t, uint8_t, uint8_t, uint8_t, bool, bool>& meta,
+           const std::array<uint16_t, MAX_BLOCKS>& sorted_blocks)
+        : repr(repr_cooked{create_meta(meta), sorted_blocks}) {}
 
-  auto ToString() const -> std::string;
+    puzzle(const uint64_t byte_0, const uint64_t byte_1, const uint64_t byte_2, const uint64_t byte_3)
+        : repr(create_repr(byte_0, byte_1, byte_2, byte_3)) {}
 
-  auto GetPrincipalDirs() const -> int;
+    puzzle(const uint16_t meta, const std::array<uint16_t, MAX_BLOCKS>& blocks)
+        : repr(repr_cooked{meta, blocks}) {}
 
-  auto Covers(int xx, int yy) const -> bool;
-
-  auto Collides(const Block &other) const -> bool;
-};
-
-// A state is represented by a string "MWHXYblocks", where M is "R"
-// (restricted) or "F" (free), W is the board width, H is the board height, X
-// is the target block x goal, Y is the target block y goal and blocks is an
-// enumeration of each of the board's cells, with each cell being a 2-letter
-// or 2-digit block representation (a 3x3 board would have a string
-// representation with length 5 + 3*3 * 2). The board's cells are enumerated
-// from top-left to bottom-right with each block's pivot being its top-left
-// corner.
-class State {
-public:
-  static constexpr int prefix = 5;
-
-  int width;
-  int height;
-  int target_x;
-  int target_y;
-  bool restricted; // Only allow blocks to move in their principal direction
-  std::string state;
-
-  // https://en.cppreference.com/w/cpp/iterator/input_iterator.html
-  class BlockIterator {
-  public:
-    using difference_type = std::ptrdiff_t;
-    using value_type = Block;
-
-  private:
-    const State &state;
-    int current_pos;
-
-  public:
-    BlockIterator(const State &_state) : state(_state), current_pos(0) {}
-
-    BlockIterator(const State &_state, int _current_pos)
-        : state(_state), current_pos(_current_pos) {}
-
-    Block operator*() const {
-      return Block(current_pos % state.width, current_pos / state.width,
-                   state.state.substr(current_pos * 2 + prefix, 2));
+    puzzle(const uint8_t w, const uint8_t h, const uint8_t tx, const uint8_t ty, const bool r, const bool g)
+        : repr(create_repr(w, h, tx, ty, r, g, invalid_blocks()))
+    {
+        if (w < MIN_WIDTH || w > MAX_WIDTH || h < MIN_HEIGHT || h > MAX_HEIGHT) {
+            throw std::invalid_argument("Board size out of bounds");
+        }
+        if (tx >= MAX_WIDTH || ty >= MAX_HEIGHT) {
+            throw std::invalid_argument("Goal out of bounds");
+        }
     }
 
-    BlockIterator &operator++() {
-      do {
-        current_pos++;
-      } while (state.state.substr(current_pos * 2 + prefix, 2) == "..");
-      return *this;
+    puzzle(const uint8_t w, const uint8_t h, const uint8_t tx, const uint8_t ty, const bool r, const bool g,
+           const std::array<uint16_t, MAX_BLOCKS>& b)
+        : repr(create_repr(w, h, tx, ty, r, g, b))
+    {
+        if (w < MIN_WIDTH || w > MAX_WIDTH || h < MIN_HEIGHT || h > MAX_HEIGHT) {
+            throw std::invalid_argument("Board size out of bounds");
+        }
+        if (tx >= MAX_WIDTH || ty >= MAX_HEIGHT) {
+            throw std::invalid_argument("Goal out of bounds");
+        }
     }
 
-    bool operator==(const BlockIterator &other) {
-      return state == other.state && current_pos == other.current_pos;
-    }
-
-    bool operator!=(const BlockIterator &other) { return !(*this == other); }
-  };
+    explicit puzzle(const std::string& string_repr)
+        : repr(create_repr(string_repr)) {}
 
 public:
-  State(int _width, int _height, int _target_x, int _target_y, bool _restricted)
-      : width(_width), height(_height), target_x(_target_x),
-        target_y(_target_y), restricted(_restricted),
-        state(std::format("{}{}{}{}{}{}", _restricted ? "R" : "F", _width,
-                          _height, _target_x, _target_y,
-                          std::string(_width * _height * 2, '.'))) {
-    if (_width < 1 || _width > 9 || _height < 1 || _height > 9) {
-      std::println("State width/height must be in [1, 9]!");
-      exit(1);
+    auto operator==(const puzzle& other) const -> bool
+    {
+        return repr.raw == other.repr.raw;
     }
-    if (_target_x < 0 || _target_x >= 9 || _target_y < 0 || _target_y >= 9) {
-      if (_target_x != 9 && _target_y != 9) {
-        std::println("State target  must be within the board bounds!");
-        exit(1);
-      }
+
+    auto operator!=(const puzzle& other) const -> bool
+    {
+        return repr.raw != other.repr.raw;
     }
-  }
 
-  State(int _width, int _height, bool _restricted)
-      : State(_width, _height, 9, 9, _restricted) {}
+    auto operator<(const puzzle& other) const -> bool
+    {
+        // Start from MSB and go to LSB. If equal, check the next.
+        for (int i = 3; i >= 0; --i) {
+            if (repr.raw[i] < other.repr.raw[i]) {
+                return true;
+            }
+            if (repr.raw[i] > other.repr.raw[i]) {
+                return false;
+            }
+        }
 
-  State() : State(4, 5, 9, 9, false) {}
-
-  explicit State(std::string _state)
-      : width(std::stoi(_state.substr(1, 1))),
-        height(std::stoi(_state.substr(2, 1))),
-        target_x(std::stoi(_state.substr(3, 1))),
-        target_y(std::stoi(_state.substr(4, 1))),
-        restricted(_state.substr(0, 1) == "R"), state(_state) {
-    if (width < 1 || width > 9 || height < 1 || height > 9) {
-      std::println("State width/height must be in [1, 9]!");
-      exit(1);
+        // All are equal
+        return false;
     }
-    if (target_x < 0 || target_x >= 9 || target_y < 0 || target_y >= 9) {
-      if (target_x != 9 && target_y != 9) {
-        std::println("State target  must be within the board bounds!");
-        exit(1);
-      }
+
+    auto operator<=(const puzzle& other) const -> bool
+    {
+        return *this < other || *this == other;
     }
-    if (static_cast<int>(_state.length()) != width * height * 2 + prefix) {
-      std::println(
-          "State representation must have length width * height * 2 + {}!",
-          prefix);
-      exit(1);
+
+    auto operator>(const puzzle& other) const -> bool
+    {
+        return !(*this <= other);
     }
-  }
 
-  bool operator==(const State &other) const { return state == other.state; }
-
-  bool operator!=(const State &other) const { return !(*this == other); }
-
-  BlockIterator begin() const {
-    BlockIterator it = BlockIterator(*this);
-    if (!(*it).IsValid()) {
-      ++it;
+    auto operator>=(const puzzle& other) const -> bool
+    {
+        return !(*this < other);
     }
-    return it;
-  }
 
-  BlockIterator end() const { return BlockIterator(*this, width * height); }
+    auto repr_view() const
+    {
+        return std::span<const uint16_t>(repr.cooked.blocks.data(), block_count());
+    }
+
+    auto block_view() const
+    {
+        return std::span<const uint16_t>(repr.cooked.blocks.data(), block_count()) | std::views::transform(
+            [](const uint16_t val)
+            {
+                return block(val);
+            });
+    }
+
+    template <typename T, typename... Rest>
+    static auto hash_combine(std::size_t& seed, const T& v, const Rest&... rest) -> void;
+
+private:
+    [[nodiscard]] static constexpr auto invalid_blocks() -> std::array<uint16_t, MAX_BLOCKS>
+    {
+        std::array<uint16_t, MAX_BLOCKS> blocks;
+        for (size_t i = 0; i < MAX_BLOCKS; ++i) {
+            blocks[i] = block::INVALID;
+        }
+        return blocks;
+    }
+
+    [[nodiscard]] static auto create_meta(const std::tuple<uint8_t, uint8_t, uint8_t, uint8_t, bool, bool>& meta) -> uint16_t;
+    [[nodiscard]] static auto create_repr(uint8_t w, uint8_t h, uint8_t tx, uint8_t ty, bool r, bool g,
+                                          const std::array<uint16_t, MAX_BLOCKS>& b) -> repr_cooked;
+
+    [[nodiscard]] static auto create_repr(uint64_t byte_0, uint64_t byte_1, uint64_t byte_2,
+                                          uint64_t byte_3) -> repr_cooked;
+
+    [[nodiscard]] static auto create_repr(const std::string& string_repr) -> repr_cooked;
+
+    // Repr setters
+    [[nodiscard]] auto set_restricted(bool restricted) const -> puzzle;
+    [[nodiscard]] auto set_width(uint8_t width) const -> puzzle;
+    [[nodiscard]] auto set_height(uint8_t height) const -> puzzle;
+    [[nodiscard]] auto set_goal(bool goal) const -> puzzle;
+    [[nodiscard]] auto set_goal_x(uint8_t target_x) const -> puzzle;
+    [[nodiscard]] auto set_goal_y(uint8_t target_y) const -> puzzle;
+    [[nodiscard]] auto set_blocks(std::array<uint16_t, MAX_BLOCKS> blocks) const -> puzzle;
 
 public:
-  auto Hash() const -> std::size_t;
+    // Repr getters
+    [[nodiscard]] auto unpack_meta() const -> std::tuple<uint8_t, uint8_t, uint8_t, uint8_t, bool, bool>;
+    [[nodiscard]] auto get_restricted() const -> bool;
+    [[nodiscard]] auto get_width() const -> uint8_t;
+    [[nodiscard]] auto get_height() const -> uint8_t;
+    [[nodiscard]] auto get_goal() const -> bool;
+    [[nodiscard]] auto get_goal_x() const -> uint8_t;
+    [[nodiscard]] auto get_goal_y() const -> uint8_t;
 
-  auto HasWinCondition() const -> bool;
+    // Util
+    [[nodiscard]] auto hash() const -> size_t;
+    [[nodiscard]] auto string_repr() const -> std::string;
+    [[nodiscard]] static auto try_parse_string_repr(const std::string& string_repr) -> std::optional<repr_cooked>;
+    [[nodiscard]] auto valid() const -> bool;
+    [[nodiscard]] auto try_get_invalid_reason() const -> std::optional<std::string>;
+    [[nodiscard]] auto block_count() const -> uint8_t;
+    [[nodiscard]] auto goal_reached() const -> bool;
+    [[nodiscard]] auto try_get_block(uint8_t x, uint8_t y) const -> std::optional<block>;
+    [[nodiscard]] auto try_get_target_block() const -> std::optional<block>;
+    [[nodiscard]] auto covers(uint8_t x, uint8_t y, uint8_t _w, uint8_t _h) const -> bool;
+    [[nodiscard]] auto covers(uint8_t x, uint8_t y) const -> bool;
+    [[nodiscard]] auto covers(block b) const -> bool;
 
-  auto IsWon() const -> bool;
+    // Editing
+    [[nodiscard]] auto toggle_restricted() const -> puzzle;
+    [[nodiscard]] auto try_set_goal(uint8_t x, uint8_t y) const -> std::optional<puzzle>;
+    [[nodiscard]] auto clear_goal() const -> puzzle;
+    [[nodiscard]] auto try_add_column() const -> std::optional<puzzle>;
+    [[nodiscard]] auto try_remove_column() const -> std::optional<puzzle>;
+    [[nodiscard]] auto try_add_row() const -> std::optional<puzzle>;
+    [[nodiscard]] auto try_remove_row() const -> std::optional<puzzle>;
+    [[nodiscard]] auto try_add_block(block b) const -> std::optional<puzzle>;
+    [[nodiscard]] auto try_remove_block(uint8_t x, uint8_t y) const -> std::optional<puzzle>;
+    [[nodiscard]] auto try_toggle_target(uint8_t x, uint8_t y) const -> std::optional<puzzle>;
+    [[nodiscard]] auto try_toggle_wall(uint8_t x, uint8_t y) const -> std::optional<puzzle>;
 
-  auto SetGoal(int x, int y) -> bool;
+    // Playing
+    [[nodiscard]] auto try_move_block_at(uint8_t x, uint8_t y, direction dir) const -> std::optional<puzzle>;
 
-  auto ClearGoal() -> void;
+    // Statespace
+    [[nodiscard]] auto try_move_block_at_fast(uint64_t bitmap, uint8_t block_idx,
+                                              direction dir) const -> std::optional<puzzle>;
+    static auto sorted_replace(std::array<uint16_t, MAX_BLOCKS> blocks, uint8_t idx,
+                               uint16_t new_val) -> std::array<uint16_t, MAX_BLOCKS>;
+    auto blocks_bitmap() const -> uint64_t;
+    static inline auto bitmap_set_bit(uint64_t bitmap, uint8_t x, uint8_t y) -> uint64_t;
+    static inline auto bitmap_get_bit(uint64_t bitmap, uint8_t x, uint8_t y) -> bool;
+    static auto bitmap_clear_block(uint64_t bitmap, block b) -> uint64_t;
+    static auto bitmap_check_collision(uint64_t bitmap, block b) -> bool;
+    static auto bitmap_check_collision(uint64_t bitmap, block b, direction dir) -> bool;
 
-  auto AddColumn() const -> State;
+    template <typename F>
+    auto for_each_adjacent(F&& callback) const -> void
+    {
+        const uint64_t bitmap = blocks_bitmap();
+        const bool r = get_restricted();
+        for (uint8_t idx = 0; idx < MAX_BLOCKS; idx++) {
+            const block b = block(repr.cooked.blocks[idx]);
+            if (!b.valid()) {
+                break;
+            }
+            if (b.get_immovable()) {
+                continue;
+            }
+            const int dirs = r ? b.principal_dirs() : nor | eas | sou | wes;
+            for (const direction d : {nor, eas, sou, wes}) {
+                if (dirs & d) {
+                    if (auto moved = try_move_block_at_fast(bitmap, idx, d)) {
+                        callback(*moved);
+                    }
+                }
+            }
+        }
+    }
 
-  auto RemoveColumn() const -> State;
-
-  auto AddRow() const -> State;
-
-  auto RemoveRow() const -> State;
-
-  auto AddBlock(const Block &block) -> bool;
-
-  auto GetBlock(int x, int y) const -> Block;
-
-  auto GetBlockAt(int x, int y) const -> std::string;
-
-  auto GetTargetBlock() const -> Block;
-
-  auto GetIndex(int x, int y) const -> int;
-
-  auto RemoveBlock(int x, int y) -> bool;
-
-  auto ToggleTarget(int x, int y) -> bool;
-
-  auto ToggleWall(int x, int y) -> bool;
-
-  auto ToggleRestricted() -> void;
-
-  auto MoveBlockAt(int x, int y, Direction dir) -> bool;
-
-  auto GetNextStates() const -> std::vector<State>;
-
-  auto Closure() const
-      -> std::pair<std::vector<State>,
-                   std::vector<std::pair<std::size_t, std::size_t>>>;
+    [[nodiscard]] auto explore_state_space() const
+        -> std::pair<std::vector<puzzle>, std::vector<std::pair<size_t, size_t>>>;
 };
 
-// Provide hash functions so we can use State and <State, State> as hash-set
-// keys for masses and springs.
-template <> struct std::hash<State> {
-  std::size_t operator()(const State &s) const noexcept { return s.Hash(); }
+// Hash functions for sets and maps
+
+struct puzzle_hasher
+{
+    auto operator()(const puzzle& s) const noexcept -> size_t
+    {
+        return s.hash();
+    }
 };
 
-template <> struct std::hash<std::pair<State, State>> {
-  std::size_t operator()(const std::pair<State, State> &s) const noexcept {
-    auto h1 = std::hash<State>{}(s.first);
-    auto h2 = std::hash<State>{}(s.second);
-    return h1 + h2 + (h1 * h2);
-  }
+struct link_hasher
+{
+    auto operator()(const std::pair<puzzle, puzzle>& s) const noexcept -> size_t
+    {
+        size_t h = 0;
+        if (s.first < s.second) {
+            puzzle::hash_combine(h, s.first, s.second);
+        } else {
+            puzzle::hash_combine(h, s.second, s.first);
+        }
+        return h;
+    }
 };
 
-template <> struct std::equal_to<std::pair<State, State>> {
-  bool operator()(const std::pair<State, State> &a,
-                  const std::pair<State, State> &b) const noexcept {
-    return (a.first == b.first && a.second == b.second) ||
-           (a.first == b.second && a.second == b.first);
-  }
+struct link_equal_to
+{
+    auto operator()(const std::pair<puzzle, puzzle>& a, const std::pair<puzzle, puzzle>& b) const noexcept -> bool
+    {
+        return (a.first == b.first && a.second == b.second) || (a.first == b.second && a.second == b.first);
+    }
 };
 
-using WinCondition = std::function<bool(const State &)>;
+template <typename T, typename... Rest>
+auto puzzle::hash_combine(std::size_t& seed, const T& v, const Rest&... rest) -> void
+{
+    auto h = []<typename HashedType>(const HashedType& val) -> std::size_t
+    {
+        if constexpr (std::is_same_v<std::decay_t<HashedType>, puzzle>) {
+            return puzzle_hasher{}(val);
+        } else if constexpr (std::is_same_v<std::decay_t<HashedType>, std::pair<puzzle, puzzle>>) {
+            return link_hasher{}(val);
+        } else {
+            return std::hash<std::decay_t<HashedType>>{}(val);
+        }
+    };
 
-#endif
+    seed ^= h(v) + 0x9e3779b9 + (seed << 6) + (seed >> 2);
+    (hash_combine(seed, rest), ...);
+}
+
+#endif

include/renderer.hpp

@@ -1,80 +1,109 @@
-#ifndef __RENDERER_HPP_
-#define __RENDERER_HPP_
+#ifndef RENDERER_HPP_
+#define RENDERER_HPP_
 
-#include "camera.hpp"
+#include "orbit_camera.hpp"
 #include "config.hpp"
-#include "gui.hpp"
-#include "input.hpp"
-#include "state.hpp"
+#include "input_handler.hpp"
+#include "state_manager.hpp"
+#include "user_interface.hpp"
 
 #include <raylib.h>
-#include <raymath.h>
+#include <rlgl.h>
 
-class Renderer {
+class renderer
+{
 private:
-  const StateManager &state;
-  const InputHandler &input;
-  Gui &gui;
+    const state_manager& state;
+    const input_handler& input;
+    user_interface& gui;
 
-  const OrbitCamera3D &camera;
-  RenderTexture render_target;
-  RenderTexture klotski_target;
-  RenderTexture menu_target;
+    const orbit_camera& camera;
+    RenderTexture render_target =
+        LoadRenderTexture(GetScreenWidth() / 2, GetScreenHeight() - MENU_HEIGHT);
 
-  // Instancing
-  Material vertex_mat;
-  std::size_t transforms_size = 0;
-  Matrix *transforms = nullptr;
-  Mesh cube_instance;
-  Shader instancing_shader;
+    // TODO: Those should be moved to the user_interface.h
+    RenderTexture klotski_target =
+        LoadRenderTexture(GetScreenWidth() / 2, GetScreenHeight() - MENU_HEIGHT);
+    RenderTexture menu_target = LoadRenderTexture(GetScreenWidth(), MENU_HEIGHT);
 
-public:
-  Renderer(const OrbitCamera3D &_camera, const StateManager &_state,
-           const InputHandler &_input, Gui &_gui)
-      : state(_state), input(_input), gui(_gui), camera(_camera) {
-    render_target = LoadRenderTexture(GetScreenWidth() / 2.0,
-                                      GetScreenHeight() - MENU_HEIGHT);
-    klotski_target = LoadRenderTexture(GetScreenWidth() / 2.0,
-                                       GetScreenHeight() - MENU_HEIGHT);
-    menu_target = LoadRenderTexture(GetScreenWidth(), MENU_HEIGHT);
-  }
-
-  Renderer(const Renderer &copy) = delete;
-  Renderer &operator=(const Renderer &copy) = delete;
-  Renderer(Renderer &&move) = delete;
-  Renderer &operator=(Renderer &&move) = delete;
-
-  ~Renderer() {
-    UnloadRenderTexture(render_target);
-    UnloadRenderTexture(klotski_target);
-    UnloadRenderTexture(menu_target);
+    // Batching
+    std::vector<std::pair<Vector3, Vector3>> connections;
 
     // Instancing
-    if (transforms != nullptr) {
-      UnloadMaterial(vertex_mat);
-      MemFree(transforms);
-      UnloadMesh(cube_instance);
+    static constexpr int INSTANCE_COLOR_ATTR = 5;
+    std::vector<Matrix> transforms;
+    std::vector<Color> colors;
+    Material vertex_mat = LoadMaterialDefault();
+    Mesh cube_instance = GenMeshCube(VERTEX_SIZE, VERTEX_SIZE, VERTEX_SIZE);
+    Shader instancing_shader =
+        LoadShader("shader/instancing_vertex.glsl", "shader/instancing_fragment.glsl");
 
-      // I think the shader already gets unloaded with the material?
-      // UnloadShader(instancing_shader);
-    }
-  }
-
-private:
-  auto AllocateGraphInstancing(std::size_t size) -> void;
-
-  auto ReallocateGraphInstancingIfNecessary(std::size_t size) -> void;
+    unsigned int color_vbo_id = 0;
 
 public:
-  auto UpdateTextureSizes() -> void;
+    renderer(const orbit_camera& _camera, const state_manager& _state, const input_handler& _input,
+             user_interface& _gui)
+        : state(_state), input(_input), gui(_gui), camera(_camera)
+    {
+        instancing_shader.locs[SHADER_LOC_MATRIX_MVP] = GetShaderLocation(instancing_shader, "mvp");
+        instancing_shader.locs[SHADER_LOC_MATRIX_MODEL] =
+            GetShaderLocationAttrib(instancing_shader, "instanceTransform");
+        instancing_shader.locs[SHADER_LOC_VECTOR_VIEW] =
+            GetShaderLocation(instancing_shader, "viewPos");
 
-  auto DrawMassSprings(const std::vector<Vector3> &masses) -> void;
+        // infoln("LOC vertexPosition: {}",
+        //        rlGetLocationAttrib(instancing_shader.id, "vertexPosition"));
+        // infoln("LOC instanceTransform: {}",
+        //        rlGetLocationAttrib(instancing_shader.id, "instanceTransform"));
+        // infoln("LOC instanceColor: {}", rlGetLocationAttrib(instancing_shader.id, "instanceColor"));
 
-  auto DrawKlotski() -> void;
+        // vertex_mat.maps[MATERIAL_MAP_DIFFUSE].color = VERTEX_COLOR;
+        vertex_mat.shader = instancing_shader;
 
-  auto DrawMenu(const std::vector<Vector3> &masses) -> void;
+        transforms.reserve(DRAW_VERTICES_LIMIT);
+        colors.reserve(DRAW_VERTICES_LIMIT);
+        color_vbo_id = rlLoadVertexBuffer(colors.data(), DRAW_VERTICES_LIMIT * sizeof(Color), true);
 
-  auto DrawTextures(int fps, int ups) -> void;
+        rlEnableVertexArray(cube_instance.vaoId);
+        rlEnableVertexBuffer(color_vbo_id);
+        rlSetVertexAttribute(INSTANCE_COLOR_ATTR, 4, RL_UNSIGNED_BYTE, true, 0, 0);
+        rlEnableVertexAttribute(INSTANCE_COLOR_ATTR);
+        rlSetVertexAttributeDivisor(INSTANCE_COLOR_ATTR, 1);
+
+        rlDisableVertexBuffer();
+        rlDisableVertexArray();
+    }
+
+    renderer(const renderer& copy) = delete;
+    auto operator=(const renderer& copy) -> renderer& = delete;
+    renderer(renderer&& move) = delete;
+    auto operator=(renderer&& move) -> renderer& = delete;
+
+    ~renderer()
+    {
+        UnloadRenderTexture(render_target);
+        UnloadRenderTexture(klotski_target);
+        UnloadRenderTexture(menu_target);
+
+        // Instancing
+        UnloadMaterial(vertex_mat);
+        UnloadMesh(cube_instance);
+
+        // I think the shader already gets unloaded with the material?
+        // UnloadShader(instancing_shader);
+    }
+
+private:
+    auto update_texture_sizes() -> void;
+
+    auto draw_mass_springs(const std::vector<Vector3>& masses) -> void;
+    auto draw_klotski() const -> void;
+    auto draw_menu() const -> void;
+    auto draw_textures(int fps, int ups, size_t mass_count, size_t spring_count) const -> void;
+
+public:
+    auto render(const std::vector<Vector3>& masses, int fps, int ups, size_t mass_count,
+                size_t spring_count) -> void;
 };
 
-#endif
+#endif

include/state.hpp

@@ -1,103 +0,0 @@
-#ifndef __STATE_HPP_
-#define __STATE_HPP_
-
-#include "config.hpp"
-#include "distance.hpp"
-#include "physics.hpp"
-#include "puzzle.hpp"
-
-#include <raymath.h>
-#include <stack>
-#include <unordered_map>
-#include <unordered_set>
-
-class StateManager {
-public:
-  ThreadedPhysics &physics;
-
-  std::vector<State> presets = {State()};
-  std::vector<std::string> comments = {"Empty"};
-
-  // Some stuff is faster to map from state to mass (e.g. in the renderer)
-  std::unordered_map<State, std::size_t> states; // State to mass id
-  std::unordered_set<State> winning_states;
-  std::unordered_map<State, int> visited_states; // How often we've been here
-  std::stack<State> history;
-
-  // Other stuff maps from mass to state :/
-  std::unordered_map<std::size_t, State> masses; // Mass id to state
-  std::vector<std::size_t> winning_path;
-
-  // Fuck it, duplicate the springs too, we don't even need to copy them from
-  // the physics thread then...
-  std::vector<std::pair<std::size_t, std::size_t>> springs;
-
-  // Distance calculation result can be buffered and reused to calculate a new
-  // path on the same graph
-  DistanceResult target_distances;
-
-  std::string preset_file;
-
-  int total_moves = 0;
-  int current_preset = 0;
-  State starting_state;
-  State current_state;
-  State previous_state;
-
-  bool edited = false;
-
-public:
-  StateManager(ThreadedPhysics &_physics, const std::string &preset_file)
-      : physics(_physics) {
-    ParsePresetFile(preset_file);
-    current_state = presets.at(current_preset);
-    ClearGraph();
-  }
-
-  StateManager(const StateManager &copy) = delete;
-  StateManager &operator=(const StateManager &copy) = delete;
-  StateManager(StateManager &&move) = delete;
-  StateManager &operator=(StateManager &&move) = delete;
-
-  ~StateManager() {}
-
-private:
-  auto ParsePresetFile(const std::string &_preset_file) -> bool;
-
-public:
-  auto AppendPresetFile(const std::string preset_name) -> void;
-
-  auto LoadPreset(int preset) -> void;
-
-  auto ResetState() -> void;
-
-  auto PreviousPreset() -> void;
-
-  auto NextPreset() -> void;
-
-  auto NextPath() -> void;
-
-  auto FillGraph() -> void;
-
-  auto UpdateGraph() -> void;
-
-  auto ClearGraph() -> void;
-
-  auto FindWinningStates() -> void;
-
-  auto FindTargetDistances() -> void;
-
-  auto FindTargetPath() -> void;
-
-  auto FindWorstState() -> State;
-
-  auto GoToWorst() -> void;
-
-  auto GoToNearestTarget() -> void;
-
-  auto PopHistory() -> void;
-
-  auto CurrentMassIndex() const -> std::size_t;
-};
-
-#endif

include/state_manager.hpp

@@ -0,0 +1,153 @@
+#ifndef STATE_MANAGER_HPP_
+#define STATE_MANAGER_HPP_
+
+#include "graph_distances.hpp"
+#include "threaded_physics.hpp"
+#include "puzzle.hpp"
+
+#include <stack>
+#include <boost/unordered/unordered_flat_map.hpp>
+#include <boost/unordered/unordered_flat_set.hpp>
+
+class state_manager
+{
+private:
+    threaded_physics& physics;
+
+    std::string preset_file;
+    size_t current_preset = 0;
+    std::vector<puzzle> preset_states = {puzzle(4, 5, 0, 0, true, false)};
+    std::vector<std::string> preset_comments = {"# Empty"};
+
+    // State storage (store states twice for bidirectional lookup).
+    // Everything else should only store indices to state_pool.
+
+    std::vector<puzzle> state_pool; // Indices are equal to mass_springs mass indices
+    boost::unordered_flat_map<puzzle, size_t, puzzle_hasher> state_indices; // Maps states to indices
+    std::vector<std::pair<size_t, size_t>> links; // Indices are equal to mass_springs springs indices
+
+    graph_distances node_target_distances; // Buffered and reused if the graph doesn't change
+    boost::unordered_flat_set<size_t> winning_indices; // Indices of all states where the board is solved
+    std::vector<size_t> winning_path; // Ordered list of node indices leading to the nearest solved state
+    boost::unordered_flat_set<size_t> path_indices; // For faster lookup if a vertex is part of the path in renderer
+
+    std::vector<size_t> move_history;                    // Moves between the starting state and the current state
+    boost::unordered_flat_map<size_t, int> visit_counts; // How often each state was visited
+
+    size_t starting_state_index = 0;
+    size_t current_state_index = 0;
+    size_t previous_state_index = 0;
+
+    int total_moves = 0;
+    bool edited = false;
+
+public:
+    state_manager(threaded_physics& _physics, const std::string& _preset_file)
+        : physics(_physics)
+    {
+        parse_preset_file(_preset_file);
+        load_preset(0);
+    }
+
+    state_manager(const state_manager& copy) = delete;
+    auto operator=(const state_manager& copy) -> state_manager& = delete;
+    state_manager(state_manager&& move) = delete;
+    auto operator=(state_manager&& move) -> state_manager& = delete;
+
+private:
+    /**
+     * Inserts a board state into the state_manager and the physics system.
+     * States should only be inserted using this function to keep both systems in sync.
+     * The function checks for duplicates before insertion.
+     *
+     * @param state State to insert
+     * @return Index of insertion (or existing index if duplicate)
+     */
+    auto synced_try_insert_state(const puzzle& state) -> size_t;
+
+    /**
+     * Inserts a state link into the state_manager and the physics system.
+     * Links should only be inserted using this function to keep both systems in sync.
+     * The function does not check for duplicates before insertion.
+     *
+     * @param first_index Index of the first linked state
+     * @param second_index Index of the second linked state
+     */
+    auto synced_insert_link(size_t first_index, size_t second_index) -> void;
+
+    /**
+     * Inserts an entire statespace into the state_manager and the physics system.
+     * If inserting many states and links in bulk, this function should always be used
+     * to not stress the physics command mutex.
+     * The function does not check for duplicates before insertion.
+     *
+     * @param states List of states to insert
+     * @param _links List of links to insert
+     */
+    auto synced_insert_statespace(const std::vector<puzzle>& states,
+                                  const std::vector<std::pair<size_t, size_t>>& _links) -> void;
+
+    /**
+     * Clears all states and links (and related) from the state_manager and the physics system.
+     * Note that this leaves any dangling indices (e.g., current_state_index) in an invalid state.
+     */
+    auto synced_clear_statespace() -> void;
+
+public:
+    // Presets
+
+    auto parse_preset_file(const std::string& _preset_file) -> bool;
+    auto append_preset_file(const std::string& preset_name) -> bool;
+    auto load_preset(size_t preset) -> void;
+    auto load_previous_preset() -> void;
+    auto load_next_preset() -> void;
+
+    // Update current_state
+
+    auto update_current_state(const puzzle& p) -> void;
+    auto edit_starting_state(const puzzle& p) -> void;
+    auto goto_starting_state() -> void;
+    auto goto_optimal_next_state() -> void;
+    auto goto_previous_state() -> void;
+    auto goto_most_distant_state() -> void;
+    auto goto_closest_target_state() -> void;
+
+    // Update graph
+
+    auto populate_graph() -> void;
+    auto clear_graph_and_add_current(const puzzle& p) -> void;
+    auto clear_graph_and_add_current() -> void;
+    auto populate_winning_indices() -> void;
+    auto populate_node_target_distances() -> void;
+    auto populate_winning_path() -> void;
+
+    // Index mapping
+
+    [[nodiscard]] auto get_index(const puzzle& state) const -> size_t;
+    [[nodiscard]] auto get_current_index() const -> size_t;
+    [[nodiscard]] auto get_starting_index() const -> size_t;
+    [[nodiscard]] auto get_state(size_t index) const -> const puzzle&;
+    [[nodiscard]] auto get_current_state() const -> const puzzle&;
+    [[nodiscard]] auto get_starting_state() const -> const puzzle&;
+
+    // Access
+    [[nodiscard]] auto get_state_count() const -> size_t;
+    [[nodiscard]] auto get_target_count() const -> size_t;
+    [[nodiscard]] auto get_link_count() const -> size_t;
+    [[nodiscard]] auto get_path_length() const -> size_t;
+    [[nodiscard]] auto get_links() const -> const std::vector<std::pair<size_t, size_t>>&;
+    [[nodiscard]] auto get_winning_indices() const -> const boost::unordered_flat_set<size_t>&;
+    [[nodiscard]] auto get_visit_counts() const -> const boost::unordered_flat_map<size_t, int>&;
+    [[nodiscard]] auto get_winning_path() const -> const std::vector<size_t>&;
+    [[nodiscard]] auto get_path_indices() const -> const boost::unordered_flat_set<size_t>&;
+    [[nodiscard]] auto get_current_visits() const -> int;
+    [[nodiscard]] auto get_current_preset() const -> size_t;
+    [[nodiscard]] auto get_preset_count() const -> size_t;
+    [[nodiscard]] auto get_current_preset_comment() const -> const std::string&;
+    [[nodiscard]] auto has_history() const -> bool;
+    [[nodiscard]] auto has_distances() const -> bool;
+    [[nodiscard]] auto get_total_moves() const -> size_t;
+    [[nodiscard]] auto was_edited() const -> bool;
+};
+
+#endif

include/threaded_physics.hpp

@@ -0,0 +1,95 @@
+#ifndef PHYSICS_HPP_
+#define PHYSICS_HPP_
+
+#include <atomic>
+#include <condition_variable>
+#include <mutex>
+#include <queue>
+#include <raylib.h>
+#include <raymath.h>
+#include <thread>
+#include <variant>
+#include <vector>
+
+#ifdef TRACY
+#include <tracy/Tracy.hpp>
+#endif
+
+class threaded_physics
+{
+    struct add_mass {};
+
+    struct add_spring
+    {
+        size_t a;
+        size_t b;
+    };
+
+    struct clear_graph {};
+
+    using command = std::variant<add_mass, add_spring, clear_graph>;
+
+    struct physics_state
+    {
+        #ifdef TRACY
+        TracyLockable(std::mutex, command_mtx);
+        #else
+        std::mutex command_mtx;
+        #endif
+        std::queue<command> pending_commands;
+
+        #ifdef TRACY
+        TracyLockable(std::mutex, data_mtx);
+        #else
+        std::mutex data_mtx;
+        #endif
+        std::condition_variable_any data_ready_cnd;
+        std::condition_variable_any data_consumed_cnd;
+        Vector3 mass_center = Vector3Zero();
+        int ups = 0;
+        size_t mass_count = 0;       // For debug
+        size_t spring_count = 0;     // For debug
+        std::vector<Vector3> masses; // Read by renderer
+        bool data_ready = false;
+        bool data_consumed = true;
+
+        std::atomic<bool> running{true};
+    };
+
+private:
+    std::thread physics;
+
+public:
+    physics_state state;
+
+public:
+    threaded_physics()
+        : physics(physics_thread, std::ref(state)) {}
+
+    threaded_physics(const threaded_physics& copy) = delete;
+    auto operator=(const threaded_physics& copy) -> threaded_physics& = delete;
+    threaded_physics(threaded_physics&& move) = delete;
+    auto operator=(threaded_physics&& move) -> threaded_physics& = delete;
+
+    ~threaded_physics()
+    {
+        state.running = false;
+        state.data_ready_cnd.notify_all();
+        state.data_consumed_cnd.notify_all();
+        physics.join();
+    }
+
+private:
+    static auto physics_thread(physics_state& state) -> void;
+
+public:
+    auto add_mass_cmd() -> void;
+
+    auto add_spring_cmd(size_t a, size_t b) -> void;
+
+    auto clear_cmd() -> void;
+
+    auto add_mass_springs_cmd(size_t num_masses, const std::vector<std::pair<size_t, size_t>>& springs) -> void;
+};
+
+#endif

include/tracy.hpp

@@ -1,16 +0,0 @@
-#ifndef __TRACY_HPP_
-#define __TRACY_HPP_
-
-#include "config.hpp"
-
-#ifdef TRACY
-
-#include <cstddef>
-
-void *operator new(std::size_t count);
-void operator delete(void *ptr) noexcept;
-void operator delete(void *ptr, std::size_t count) noexcept;
-
-#endif
-
-#endif

include/user_interface.hpp

@@ -0,0 +1,186 @@
+#ifndef GUI_HPP_
+#define GUI_HPP_
+
+#include "orbit_camera.hpp"
+#include "config.hpp"
+#include "input_handler.hpp"
+#include "state_manager.hpp"
+
+#include <raylib.h>
+
+class user_interface
+{
+    class grid
+    {
+    public:
+        int x;
+        int y;
+        int width;
+        int height;
+        int columns;
+        int rows;
+        const int padding;
+
+    public:
+        grid(const int _x, const int _y, const int _width, const int _height, const int _columns,
+             const int _rows, const int _padding)
+            : x(_x), y(_y), width(_width), height(_height), columns(_columns), rows(_rows),
+              padding(_padding)
+        {}
+
+    public:
+        auto update_bounds(int _x, int _y, int _width, int _height, int _columns, int _rows)
+            -> void;
+        auto update_bounds(int _x, int _y, int _width, int _height) -> void;
+        auto update_bounds(int _x, int _y) -> void;
+
+        [[nodiscard]] auto bounds() const -> Rectangle;
+        [[nodiscard]] auto bounds(int _x, int _y, int _width, int _height) const -> Rectangle;
+
+        [[nodiscard]] auto square_bounds() const -> Rectangle;
+        [[nodiscard]] auto square_bounds(int _x, int _y, int _width, int _height) const
+            -> Rectangle;
+    };
+
+    struct style
+    {
+        int border_color_normal;
+        int base_color_normal;
+        int text_color_normal;
+
+        int border_color_focused;
+        int base_color_focused;
+        int text_color_focused;
+
+        int border_color_pressed;
+        int base_color_pressed;
+        int text_color_pressed;
+
+        int border_color_disabled;
+        int base_color_disabled;
+        int text_color_disabled;
+    };
+
+    struct default_style : style
+    {
+        int background_color;
+        int line_color;
+
+        int text_size;
+        int text_spacing;
+        int text_line_spacing;
+        int text_alignment_vertical;
+        int text_wrap_mode;
+    };
+
+    struct component_style : style
+    {
+        int border_width;
+        int text_padding;
+        int text_alignment;
+    };
+
+private:
+    input_handler& input;
+    state_manager& state;
+    const orbit_camera& camera;
+
+    grid menu_grid = grid(0, 0, GetScreenWidth(), MENU_HEIGHT, MENU_COLS, MENU_ROWS, MENU_PAD);
+
+    grid board_grid =
+        grid(0, MENU_HEIGHT, GetScreenWidth() / 2, GetScreenHeight() - MENU_HEIGHT,
+             state.get_current_state().get_width(), state.get_current_state().get_height(), BOARD_PADDING);
+
+    grid graph_overlay_grid = grid(GetScreenWidth() / 2, MENU_HEIGHT, 200, 100, 1, 4, MENU_PAD);
+
+    grid debug_overlay_grid =
+        grid(GetScreenWidth() / 2, GetScreenHeight() - 75, 200, 75, 1, 3, MENU_PAD);
+
+    // Windows
+
+    std::string message_title;
+    std::string message_message;
+    std::function<void()> yes_no_handler;
+    bool ok_message = false;
+    bool yes_no_message = false;
+    bool save_window = false;
+    std::array<char, 256> preset_name = {};
+    bool help_window = false;
+
+public:
+    user_interface(input_handler& _input, state_manager& _state, const orbit_camera& _camera)
+        : input(_input), state(_state), camera(_camera)
+    {
+        init();
+    }
+
+    user_interface(const user_interface& copy) = delete;
+    auto operator=(const user_interface& copy) -> user_interface& = delete;
+    user_interface(user_interface&& move) = delete;
+    auto operator=(user_interface&& move) -> user_interface& = delete;
+
+private:
+    static auto init() -> void;
+
+    static auto apply_color(style& style, Color color) -> void;
+    static auto apply_block_color(style& style, Color color) -> void;
+    static auto apply_text_color(style& style, Color color) -> void;
+
+    static auto get_default_style() -> default_style;
+    static auto set_default_style(const default_style& style) -> void;
+    static auto get_component_style(int component) -> component_style;
+    static auto set_component_style(int component, const component_style& style) -> void;
+
+    [[nodiscard]] static auto popup_bounds() -> Rectangle;
+
+    auto draw_button(Rectangle bounds, const std::string& label, Color color, bool enabled = true,
+                     int font_size = FONT_SIZE) const -> int;
+
+    auto draw_menu_button(int x, int y, int width, int height, const std::string& label,
+                          Color color, bool enabled = true, int font_size = FONT_SIZE) const -> int;
+
+    auto draw_toggle_slider(Rectangle bounds, const std::string& off_label,
+                            const std::string& on_label, int* active, Color color,
+                            bool enabled = true, int font_size = FONT_SIZE) const -> int;
+
+    auto draw_menu_toggle_slider(int x, int y, int width, int height, const std::string& off_label,
+                                 const std::string& on_label, int* active, Color color,
+                                 bool enabled = true, int font_size = FONT_SIZE) const -> int;
+
+    auto draw_spinner(Rectangle bounds, const std::string& label, int* value, int min, int max,
+                      Color color, bool enabled = true, int font_size = FONT_SIZE) const -> int;
+
+    auto draw_menu_spinner(int x, int y, int width, int height, const std::string& label,
+                           int* value, int min, int max, Color color, bool enabled = true,
+                           int font_size = FONT_SIZE) const -> int;
+
+    auto draw_label(Rectangle bounds, const std::string& text, Color color, bool enabled = true,
+                    int font_size = FONT_SIZE) const -> int;
+
+    auto draw_board_block(int x, int y, int width, int height, Color color,
+                          bool enabled = true) const -> bool;
+
+    [[nodiscard]] auto window_open() const -> bool;
+
+    // Different menu sections
+    auto draw_menu_header(Color color) const -> void;
+    auto draw_graph_info(Color color) const -> void;
+    auto draw_graph_controls(Color color) const -> void;
+    auto draw_camera_controls(Color color) const -> void;
+    auto draw_puzzle_controls(Color color) const -> void;
+    auto draw_edit_controls(Color color) const -> void;
+    auto draw_menu_footer(Color color) -> void;
+
+public:
+    static auto get_background_color() -> Color;
+    auto help_popup() -> void;
+    auto draw_save_preset_popup() -> void;
+    auto draw_ok_message_box() -> void;
+    auto draw_yes_no_message_box() -> void;
+    auto draw_main_menu() -> void;
+    auto draw_puzzle_board() -> void;
+    auto draw_graph_overlay(int fps, int ups, size_t mass_count, size_t spring_count) -> void;
+    auto draw(int fps, int ups, size_t mass_count, size_t spring_count) -> void;
+};
+
+#endif

include/util.hpp

@@ -1,20 +1,164 @@
-#ifndef __UTIL_HPP_
-#define __UTIL_HPP_
-
-#include "config.hpp"
+#ifndef UTIL_HPP_
+#define UTIL_HPP_
 
 #include <iostream>
 #include <raylib.h>
-#include <raymath.h>
 
-inline std::ostream &operator<<(std::ostream &os, const Vector2 &v) {
-  os << "(" << v.x << ", " << v.y << ")";
-  return os;
+// Bit shifting + masking
+
+template <class T>
+    requires std::unsigned_integral<T>
+auto create_mask(const uint8_t first, const uint8_t last) -> T
+{
+    // If the mask width is equal the type width return all 1s instead of shifting
+    // as shifting by type-width is undefined behavior.
+    if (static_cast<size_t>(last - first + 1) >= sizeof(T) * 8) {
+        return ~T{0};
+    }
+
+    // Example: first=4, last=7, 7-4+1=4
+    //           1 << 4 = 0b00010000
+    //          32  - 1 = 0b00001111
+    //          31 << 4 = 0b11110000
+    // Subtracting 1 generates a consecutive mask.
+    return ((T{1} << (last - first + 1)) - 1) << first;
 }
 
-inline std::ostream &operator<<(std::ostream &os, const Vector3 &v) {
-  os << "(" << v.x << ", " << v.y << ", " << v.z << ")";
-  return os;
+template <class T>
+    requires std::unsigned_integral<T>
+auto clear_bits(T& bits, const uint8_t first, const uint8_t last) -> void
+{
+    const T mask = create_mask<T>(first, last);
+
+    bits = bits & ~mask;
 }
 
-#endif
+template <class T, class U>
+    requires std::unsigned_integral<T> && std::unsigned_integral<U>
+auto set_bits(T& bits, const uint8_t first, const uint8_t last, const U value) -> void
+{
+    const T mask = create_mask<T>(first, last);
+
+    // Example: first=4, last=6, value=0b1110,   bits = 0b 01111110
+    //          mask                                  = 0b 01110000
+    //          bits & ~mask                          = 0b 00001110
+    //          value << 4                            = 0b 11100000
+    //          (value << 4) & mask                   = 0b 01100000
+    //          (bits & ~mask) | (value << 4) & mask  = 0b 01101110
+    //                                 Insert position:     ^^^
+    // First clear the bits, then | with the value positioned at the insertion point.
+    // The value may be larger than [first, last], extra bits are ignored.
+    bits = (bits & ~mask) | ((static_cast<T>(value) << first) & mask);
+}
+
+template <class T>
+    requires std::unsigned_integral<T>
+auto get_bits(const T bits, const uint8_t first, const uint8_t last) -> T
+{
+    const T mask = create_mask<T>(first, last);
+
+    // We can >> without sign extension because T is unsigned_integral
+    return (bits & mask) >> first;
+}
+
+// std::variant visitor
+
+// https://en.cppreference.com/w/cpp/utility/variant/visit
+template <class... Ts>
+struct overloads : Ts...
+{
+    using Ts::operator()...;
+};
+
+// Enums
+
+enum direction
+{
+    nor = 1 << 0,
+    eas = 1 << 1,
+    sou = 1 << 2,
+    wes = 1 << 3,
+};
+
+enum ctrl
+{
+    reset = 0,
+    bold_bright = 1,
+    underline = 4,
+    inverse = 7,
+    bold_bright_off = 21,
+    underline_off = 24,
+    inverse_off = 27
+};
+
+enum fg
+{
+    fg_black = 30,
+    fg_red = 31,
+    fg_green = 32,
+    fg_yellow = 33,
+    fg_blue = 34,
+    fg_magenta = 35,
+    fg_cyan = 36,
+    fg_white = 37
+};
+
+enum bg
+{
+    bg_black = 40,
+    bg_red = 41,
+    bg_green = 42,
+    bg_yellow = 43,
+    bg_blue = 44,
+    bg_magenta = 45,
+    bg_cyan = 46,
+    bg_white = 47
+};
+
+// Output
+
+inline auto operator<<(std::ostream& os, const Vector2& v) -> std::ostream&
+{
+    os << "(" << v.x << ", " << v.y << ")";
+    return os;
+}
+
+inline auto operator<<(std::ostream& os, const Vector3& v) -> std::ostream&
+{
+    os << "(" << v.x << ", " << v.y << ", " << v.z << ")";
+    return os;
+}
+
+inline auto ansi_bold_fg(const fg color) -> std::string
+{
+    return std::format("\033[1;{}m", static_cast<int>(color));
+}
+
+inline auto ansi_reset() -> std::string
+{
+    return "\033[0m";
+}
+
+// std::println doesn't work with mingw
+template <typename... Args>
+auto infoln(std::format_string<Args...> fmt, Args&&... args) -> void
+{
+    std::cout << std::format("[{}INFO{}]: ", ansi_bold_fg(fg_blue), ansi_reset()) << std::format(
+        fmt, std::forward<Args>(args)...) << std::endl;
+}
+
+template <typename... Args>
+auto warnln(std::format_string<Args...> fmt, Args&&... args) -> void
+{
+    std::cout << std::format("[{}WARNING{}]: ", ansi_bold_fg(fg_yellow), ansi_reset()) << std::format(
+        fmt, std::forward<Args>(args)...) << std::endl;
+}
+
+template <typename... Args>
+auto errln(std::format_string<Args...> fmt, Args&&... args) -> void
+{
+    std::cout << std::format("[{}ERROR{}]: ", ansi_bold_fg(fg_red), ansi_reset()) << std::format(
+        fmt, std::forward<Args>(args)...) << std::endl;
+}
+
+#endif

shader/instancing_fragment.glsl

@@ -1,8 +1,9 @@
 #version 330
 
-uniform vec4 colDiffuse;
+in vec4 fragColor;
 out vec4 finalColor;
 
 void main() {
-    finalColor = colDiffuse;
-}
+    // Advanced coloring. CG lecture really paying off now
+    finalColor = fragColor;
+}

shader/instancing_vertex.glsl

@@ -1,10 +1,14 @@
 #version 330
 
-in vec3 vertexPosition;
-in mat4 instanceTransform;
+layout(location=0) in vec3 vertexPosition;
+layout(location=1) in mat4 instanceTransform;
+layout(location=5) in vec4 instanceColor;
 
 uniform mat4 mvp;
 
+out vec4 fragColor;
+
 void main() {
+     fragColor = instanceColor;
     gl_Position = mvp * instanceTransform * vec4(vertexPosition, 1.0);
-}
+}

src/backward.cpp

@@ -2,14 +2,14 @@
 //
 // On GNU/Linux, you have few choices to get the most out of your stack trace.
 //
-// By default you get:
-//	- object filename
-//	- function name
+// By default, you get:
+//  - object filename
+//  - function name
 //
 // In order to add:
-//	- source filename
-//	- line and column numbers
-//	- source code snippet (assuming the file is accessible)
+//  - source filename
+//  - line and column numbers
+//  - source code snippet (assuming the file is accessible)
 
 // Install one of the following libraries then uncomment one of the macro (or
 // better, add the detection of the lib and the macro definition in your build
@@ -33,16 +33,13 @@
 // - g++/clang++ -lunwind
 // #define BACKWARD_HAS_LIBUNWIND 1
 
-#include "config.hpp"
-
 #ifdef BACKWARD
 
-#include "backward.hpp"
-
-namespace backward {
-
-backward::SignalHandling sh;
+    #include "backward.hpp"
 
+namespace backward
+{
+SignalHandling sh;
 } // namespace backward
 
 #endif

src/camera.cpp

@@ -1,69 +0,0 @@
-#include "camera.hpp"
-#include "config.hpp"
-
-#include <raylib.h>
-#include <raymath.h>
-
-#ifdef TRACY
-#include "tracy.hpp"
-#include <tracy/Tracy.hpp>
-#endif
-
-auto OrbitCamera3D::Rotate(Vector2 last_mouse, Vector2 mouse) -> void {
-  Vector2 dx = Vector2Subtract(mouse, last_mouse);
-
-  angle_x -= dx.x * ROT_SPEED / 200.0;
-  angle_y += dx.y * ROT_SPEED / 200.0;
-
-  angle_y = Clamp(angle_y, -1.5, 1.5); // Prevent flipping
-}
-
-auto OrbitCamera3D::Pan(Vector2 last_mouse, Vector2 mouse) -> void {
-  Vector2 dx = Vector2Subtract(mouse, last_mouse);
-
-  float speed;
-  if (IsKeyDown(KEY_LEFT_SHIFT)) {
-    speed = distance * PAN_SPEED / 1000.0 * PAN_MULTIPLIER;
-  } else {
-    speed = distance * PAN_SPEED / 1000.0;
-  }
-
-  // The panning needs to happen in camera coordinates, otherwise rotating the
-  // camera breaks it
-  Vector3 forward =
-      Vector3Normalize(Vector3Subtract(camera.target, camera.position));
-  Vector3 right = Vector3Normalize(Vector3CrossProduct(forward, camera.up));
-  Vector3 up = Vector3Normalize(Vector3CrossProduct(right, forward));
-
-  Vector3 offset = Vector3Add(Vector3Scale(right, -dx.x * speed),
-                              Vector3Scale(up, dx.y * speed));
-
-  target = Vector3Add(target, offset);
-}
-
-auto OrbitCamera3D::Update(const Vector3 &current_target, bool lock) -> void {
-  if (lock) {
-    target = Vector3MoveTowards(
-        target, current_target,
-        CAMERA_SMOOTH_SPEED * GetFrameTime() *
-            Vector3Length(Vector3Subtract(target, current_target)));
-  }
-
-  distance = Clamp(distance, MIN_CAMERA_DISTANCE, MAX_CAMERA_DISTANCE);
-  int actual_distance = distance;
-  if (projection == CAMERA_ORTHOGRAPHIC) {
-    actual_distance = MAX_CAMERA_DISTANCE;
-  }
-
-  // Spherical coordinates
-  float x = cos(angle_y) * sin(angle_x) * actual_distance;
-  float y = sin(angle_y) * actual_distance;
-  float z = cos(angle_y) * cos(angle_x) * actual_distance;
-
-  fov = Clamp(fov, 25.0, 155.0);
-
-  camera.position = Vector3Add(target, Vector3(x, y, z));
-  camera.target = target;
-  camera.fovy = fov;
-  camera.projection = projection;
-}

src/distance.cpp

@@ -1,78 +0,0 @@
-#include "distance.hpp"
-#include "config.hpp"
-
-#include <cstddef>
-#include <queue>
-
-#ifdef TRACY
-#include "tracy.hpp"
-#include <tracy/Tracy.hpp>
-#endif
-
-auto DistanceResult::Clear() -> void {
-  distances.clear();
-  parents.clear();
-  nearest_targets.clear();
-}
-
-auto DistanceResult::Empty() -> bool {
-  return distances.empty() || parents.empty() || nearest_targets.empty();
-}
-
-auto CalculateDistances(
-    std::size_t node_count,
-    const std::vector<std::pair<std::size_t, std::size_t>> &edges,
-    const std::vector<std::size_t> &targets) -> DistanceResult {
-
-  // Build a list of adjacent nodes to speed up BFS
-  std::vector<std::vector<std::size_t>> adjacency(node_count);
-  for (const auto &[from, to] : edges) {
-    adjacency[from].push_back(to);
-    adjacency[to].push_back(from);
-  }
-
-  std::vector<int> distances(node_count, -1);
-  std::vector<std::size_t> parents(node_count, -1);
-  std::vector<std::size_t> nearest_targets(node_count, -1);
-
-  std::queue<std::size_t> queue;
-  for (std::size_t target : targets) {
-    distances[target] = 0;
-    nearest_targets[target] = target;
-    queue.push(target);
-  }
-
-  while (!queue.empty()) {
-    std::size_t current = queue.front();
-    queue.pop();
-
-    for (std::size_t neighbor : adjacency[current]) {
-      if (distances[neighbor] == -1) {
-        // If distance is -1 we haven't visited the node yet
-        distances[neighbor] = distances[current] + 1;
-        parents[neighbor] = current;
-        nearest_targets[neighbor] = nearest_targets[current];
-
-        queue.push(neighbor);
-      }
-    }
-  }
-
-  return {distances, parents, nearest_targets};
-}
-
-auto GetPath(const DistanceResult &result, std::size_t source)
-    -> std::vector<std::size_t> {
-  if (result.distances[source] == -1) {
-    // Unreachable
-    return {};
-  }
-
-  std::vector<std::size_t> path;
-  for (std::size_t n = source; n != static_cast<std::size_t>(-1);
-       n = result.parents[n]) {
-    path.push_back(n);
-  }
-
-  return path;
-}

src/graph_distances.cpp

@@ -0,0 +1,73 @@
+#include "graph_distances.hpp"
+
+#include <queue>
+
+#ifdef TRACY
+    #include <tracy/Tracy.hpp>
+#endif
+
+auto graph_distances::clear() -> void
+{
+    distances.clear();
+    parents.clear();
+    nearest_targets.clear();
+}
+
+auto graph_distances::empty() const -> bool
+{
+    return distances.empty() || parents.empty() || nearest_targets.empty();
+}
+
+auto graph_distances::calculate_distances(const size_t node_count,
+                                          const std::vector<std::pair<size_t, size_t>>& edges,
+                                          const std::vector<size_t>& targets) -> void
+{
+    // Build a list of adjacent nodes to speed up BFS
+    std::vector<std::vector<size_t>> adjacency(node_count);
+    for (const auto& [from, to] : edges) {
+        adjacency[from].push_back(to);
+        adjacency[to].push_back(from);
+    }
+
+    distances = std::vector<int>(node_count, -1);
+    parents = std::vector<size_t>(node_count, -1);
+    nearest_targets = std::vector<size_t>(node_count, -1);
+
+    std::queue<size_t> queue;
+    for (size_t target : targets) {
+        distances[target] = 0;
+        nearest_targets[target] = target;
+        queue.push(target);
+    }
+
+    while (!queue.empty()) {
+        const size_t current = queue.front();
+        queue.pop();
+
+        for (size_t neighbor : adjacency[current]) {
+            if (distances[neighbor] == -1) {
+                // If distance is -1 we haven't visited the node yet
+                distances[neighbor] = distances[current] + 1;
+                parents[neighbor] = current;
+                nearest_targets[neighbor] = nearest_targets[current];
+
+                queue.push(neighbor);
+            }
+        }
+    }
+}
+
+auto graph_distances::get_shortest_path(const size_t source) const -> std::vector<size_t>
+{
+    if (empty() || distances[source] == -1) {
+        // Unreachable
+        return {};
+    }
+
+    std::vector<size_t> path;
+    for (size_t n = source; n != static_cast<size_t>(-1); n = parents[n]) {
+        path.push_back(n);
+    }
+
+    return path;
+}

src/gui.cpp

@@ -1,792 +0,0 @@
-#include "gui.hpp"
-#include "config.hpp"
-
-#include <raylib.h>
-
-#define RAYGUI_IMPLEMENTATION
-#include <raygui.h>
-
-#ifdef TRACY
-#include "tracy.hpp"
-#include <tracy/Tracy.hpp>
-#endif
-
-auto Grid::UpdateBounds(int _x, int _y, int _width, int _height, int _columns,
-                        int _rows) -> void {
-  x = _x;
-  y = _y;
-  width = _width;
-  height = _height;
-  columns = _columns;
-  rows = _rows;
-}
-
-auto Grid::UpdateBounds(int _x, int _y, int _width, int _height) -> void {
-  x = _x;
-  y = _y;
-  width = _width;
-  height = _height;
-}
-
-auto Grid::UpdateBounds(int _x, int _y) -> void {
-  x = _x;
-  y = _y;
-}
-
-auto Grid::Bounds() const -> Rectangle {
-  Rectangle bounds = Bounds(0, 0, columns, rows);
-  bounds.x -= padding;
-  bounds.y -= padding;
-  bounds.width += 2 * padding;
-  bounds.height += 2 * padding;
-  return bounds;
-}
-
-auto Grid::Bounds(int _x, int _y, int _width, int _height) const -> Rectangle {
-  if (_x < 0 || _x + _width > columns || _y < 0 || _y + _height > rows) {
-    std::println("Grid bounds are outside range.");
-    exit(1);
-  }
-
-  int cell_width = (width - padding) / columns;
-  int cell_height = (height - padding) / rows;
-
-  return Rectangle(
-      x + _x * cell_width + padding, y + _y * cell_height + padding,
-      _width * cell_width - padding, _height * cell_height - padding);
-}
-
-auto Grid::SquareBounds() const -> Rectangle {
-  Rectangle bounds = SquareBounds(0, 0, columns, rows);
-  bounds.x -= padding;
-  bounds.y -= padding;
-  bounds.width += 2 * padding;
-  bounds.height += 2 * padding;
-  return bounds;
-}
-
-auto Grid::SquareBounds(int _x, int _y, int _width, int _height) const
-    -> Rectangle {
-  // Assumes each cell is square, so either width or height are not completely
-  // filled
-
-  if (_x < 0 || _x + _width > columns || _y < 0 || _y + _height > rows) {
-    std::println("Grid bounds are outside range.");
-    exit(1);
-  }
-
-  int available_width = width - padding * (columns + 1);
-  int available_height = height - padding * (rows + 1);
-  int cell_size = std::min(available_width / columns, available_height / rows);
-
-  int grid_width = cell_size * columns + padding * (columns + 1);
-  int grid_height = cell_size * rows + padding * (rows + 1);
-  int x_offset = (width - grid_width) / 2;
-  int y_offset = (height - grid_height) / 2;
-
-  return Rectangle(x_offset + _x * (cell_size + padding) + padding,
-                   y_offset + _y * (cell_size + padding) + padding,
-                   _width * cell_size + padding * (_width - 1),
-                   _height * cell_size + padding * (_height - 1));
-}
-
-auto Gui::Init() const -> void {
-  Font font = LoadFontEx(FONT, FONT_SIZE, 0, 0);
-  SetTextureFilter(font.texture, TEXTURE_FILTER_BILINEAR);
-  GuiSetFont(font);
-
-  DefaultStyle style = GetDefaultStyle();
-  style.text_size = FONT_SIZE;
-  ApplyColor(style, GRAY);
-
-  SetDefaultStyle(style);
-}
-
-auto Gui::ApplyColor(Style &style, Color color) const -> void {
-  style.base_color_normal = ColorToInt(Fade(color, 0.5));
-  style.base_color_focused = ColorToInt(Fade(color, 0.3));
-  style.base_color_pressed = ColorToInt(Fade(color, 0.8));
-  style.base_color_disabled = style.base_color_normal;
-
-  style.border_color_normal = ColorToInt(Fade(color, 1.0));
-  style.border_color_focused = ColorToInt(Fade(color, 0.7));
-  style.border_color_pressed = ColorToInt(Fade(color, 1.0));
-  style.border_color_disabled = style.base_color_normal;
-
-  style.text_color_normal = ColorToInt(Fade(BLACK, 0.7));
-  style.text_color_focused = ColorToInt(Fade(BLACK, 0.7));
-  style.text_color_pressed = ColorToInt(Fade(BLACK, 0.7));
-  style.text_color_disabled = style.text_color_normal;
-}
-
-auto Gui::ApplyBlockColor(Style &style, Color color) const -> void {
-  style.base_color_normal = ColorToInt(Fade(color, 0.5));
-  style.base_color_focused = ColorToInt(Fade(color, 0.3));
-  style.base_color_pressed = ColorToInt(Fade(color, 0.8));
-  style.base_color_disabled = style.base_color_normal;
-
-  style.border_color_normal = ColorToInt(Fade(color, 1.0));
-  style.border_color_focused = ColorToInt(Fade(color, 0.7));
-  style.border_color_pressed = ColorToInt(Fade(color, 1.0));
-  style.border_color_disabled = style.base_color_normal;
-}
-
-auto Gui::ApplyTextColor(Style &style, Color color) const -> void {
-  style.text_color_normal = ColorToInt(Fade(color, 1.0));
-  style.text_color_focused = ColorToInt(Fade(color, 1.0));
-  style.text_color_pressed = ColorToInt(Fade(color, 1.0));
-  style.text_color_disabled = ColorToInt(Fade(BLACK, 0.7));
-}
-
-auto Gui::GetDefaultStyle() const -> DefaultStyle {
-  // Could've iterated over the values but then it wouldn't be as nice to
-  // access...
-  return {GuiGetStyle(DEFAULT, BORDER_COLOR_NORMAL),
-          GuiGetStyle(DEFAULT, BASE_COLOR_NORMAL),
-          GuiGetStyle(DEFAULT, TEXT_COLOR_NORMAL),
-
-          GuiGetStyle(DEFAULT, BORDER_COLOR_FOCUSED),
-          GuiGetStyle(DEFAULT, BASE_COLOR_FOCUSED),
-          GuiGetStyle(DEFAULT, TEXT_COLOR_FOCUSED),
-
-          GuiGetStyle(DEFAULT, BORDER_COLOR_PRESSED),
-          GuiGetStyle(DEFAULT, BASE_COLOR_PRESSED),
-          GuiGetStyle(DEFAULT, TEXT_COLOR_PRESSED),
-
-          GuiGetStyle(DEFAULT, BORDER_COLOR_DISABLED),
-          GuiGetStyle(DEFAULT, BASE_COLOR_DISABLED),
-          GuiGetStyle(DEFAULT, TEXT_COLOR_DISABLED),
-
-          GuiGetStyle(DEFAULT, BACKGROUND_COLOR),
-          GuiGetStyle(DEFAULT, LINE_COLOR),
-
-          GuiGetStyle(DEFAULT, TEXT_SIZE),
-          GuiGetStyle(DEFAULT, TEXT_SPACING),
-          GuiGetStyle(DEFAULT, TEXT_LINE_SPACING),
-          GuiGetStyle(DEFAULT, TEXT_ALIGNMENT_VERTICAL),
-          GuiGetStyle(DEFAULT, TEXT_WRAP_MODE)};
-}
-
-auto Gui::SetDefaultStyle(const DefaultStyle &style) const -> void {
-  GuiSetStyle(DEFAULT, BORDER_COLOR_NORMAL, style.border_color_normal);
-  GuiSetStyle(DEFAULT, BASE_COLOR_NORMAL, style.base_color_normal);
-  GuiSetStyle(DEFAULT, TEXT_COLOR_NORMAL, style.text_color_normal);
-
-  GuiSetStyle(DEFAULT, BORDER_COLOR_FOCUSED, style.border_color_focused);
-  GuiSetStyle(DEFAULT, BASE_COLOR_FOCUSED, style.base_color_focused);
-  GuiSetStyle(DEFAULT, TEXT_COLOR_FOCUSED, style.text_color_focused);
-
-  GuiSetStyle(DEFAULT, BORDER_COLOR_PRESSED, style.border_color_pressed);
-  GuiSetStyle(DEFAULT, BASE_COLOR_PRESSED, style.base_color_pressed);
-  GuiSetStyle(DEFAULT, TEXT_COLOR_PRESSED, style.text_color_pressed);
-
-  GuiSetStyle(DEFAULT, BORDER_COLOR_DISABLED, style.border_color_disabled);
-  GuiSetStyle(DEFAULT, BASE_COLOR_DISABLED, style.base_color_disabled);
-  GuiSetStyle(DEFAULT, TEXT_COLOR_DISABLED, style.text_color_disabled);
-
-  GuiSetStyle(DEFAULT, BACKGROUND_COLOR, style.background_color);
-  GuiSetStyle(DEFAULT, LINE_COLOR, style.line_color);
-
-  GuiSetStyle(DEFAULT, TEXT_SIZE, style.text_size);
-  GuiSetStyle(DEFAULT, TEXT_SPACING, style.text_spacing);
-  GuiSetStyle(DEFAULT, TEXT_LINE_SPACING, style.text_line_spacing);
-  GuiSetStyle(DEFAULT, TEXT_ALIGNMENT_VERTICAL, style.text_alignment_vertical);
-  GuiSetStyle(DEFAULT, TEXT_WRAP_MODE, style.text_wrap_mode);
-}
-
-auto Gui::GetComponentStyle(int component) const -> ComponentStyle {
-  return {GuiGetStyle(component, BORDER_COLOR_NORMAL),
-          GuiGetStyle(component, BASE_COLOR_NORMAL),
-          GuiGetStyle(component, TEXT_COLOR_NORMAL),
-
-          GuiGetStyle(component, BORDER_COLOR_FOCUSED),
-          GuiGetStyle(component, BASE_COLOR_FOCUSED),
-          GuiGetStyle(component, TEXT_COLOR_FOCUSED),
-
-          GuiGetStyle(component, BORDER_COLOR_PRESSED),
-          GuiGetStyle(component, BASE_COLOR_PRESSED),
-          GuiGetStyle(component, TEXT_COLOR_PRESSED),
-
-          GuiGetStyle(component, BORDER_COLOR_DISABLED),
-          GuiGetStyle(component, BASE_COLOR_DISABLED),
-          GuiGetStyle(component, TEXT_COLOR_DISABLED),
-
-          GuiGetStyle(component, BORDER_WIDTH),
-          GuiGetStyle(component, TEXT_PADDING),
-          GuiGetStyle(component, TEXT_ALIGNMENT)};
-}
-
-auto Gui::SetComponentStyle(int component, const ComponentStyle &style) const
-    -> void {
-  GuiSetStyle(component, BORDER_COLOR_NORMAL, style.border_color_normal);
-  GuiSetStyle(component, BASE_COLOR_NORMAL, style.base_color_normal);
-  GuiSetStyle(component, TEXT_COLOR_NORMAL, style.text_color_normal);
-
-  GuiSetStyle(component, BORDER_COLOR_FOCUSED, style.border_color_focused);
-  GuiSetStyle(component, BASE_COLOR_FOCUSED, style.base_color_focused);
-  GuiSetStyle(component, TEXT_COLOR_FOCUSED, style.text_color_focused);
-
-  GuiSetStyle(component, BORDER_COLOR_PRESSED, style.border_color_pressed);
-  GuiSetStyle(component, BASE_COLOR_PRESSED, style.base_color_pressed);
-  GuiSetStyle(component, TEXT_COLOR_PRESSED, style.text_color_pressed);
-
-  GuiSetStyle(component, BORDER_COLOR_DISABLED, style.border_color_disabled);
-  GuiSetStyle(component, BASE_COLOR_DISABLED, style.base_color_disabled);
-  GuiSetStyle(component, TEXT_COLOR_DISABLED, style.text_color_disabled);
-
-  GuiSetStyle(component, BORDER_WIDTH, style.border_width);
-  GuiSetStyle(component, TEXT_PADDING, style.text_padding);
-  GuiSetStyle(component, TEXT_ALIGNMENT, style.text_alignment);
-}
-
-auto Gui::DrawButton(Rectangle bounds, const std::string &label, Color color,
-                     bool enabled, int font_size) const -> int {
-  // Save original styling
-  const DefaultStyle original_default = GetDefaultStyle();
-  const ComponentStyle original_button = GetComponentStyle(BUTTON);
-
-  // Change styling
-  DefaultStyle style_default = original_default;
-  ComponentStyle style_button = original_button;
-  style_default.text_size = font_size;
-  ApplyColor(style_button, color);
-  SetDefaultStyle(style_default);
-  SetComponentStyle(BUTTON, style_button);
-
-  const int state = GuiGetState();
-  if (!enabled || WindowOpen()) {
-    GuiSetState(STATE_DISABLED);
-  }
-  int pressed = GuiButton(bounds, label.data());
-  if (!enabled || WindowOpen()) {
-    GuiSetState(state);
-  }
-
-  // Restore original styling
-  SetDefaultStyle(original_default);
-  SetComponentStyle(BUTTON, original_button);
-
-  return pressed;
-}
-
-auto Gui::DrawMenuButton(int x, int y, int width, int height,
-                         const std::string &label, Color color, bool enabled,
-                         int font_size) const -> int {
-  Rectangle bounds = menu_grid.Bounds(x, y, width, height);
-  return DrawButton(bounds, label, color, enabled, font_size);
-}
-
-auto Gui::DrawToggleSlider(Rectangle bounds, const std::string &off_label,
-                           const std::string &on_label, int *active,
-                           Color color, bool enabled, int font_size) const
-    -> int {
-  // Save original styling
-  const DefaultStyle original_default = GetDefaultStyle();
-  const ComponentStyle original_slider = GetComponentStyle(SLIDER);
-  const ComponentStyle original_toggle = GetComponentStyle(TOGGLE);
-
-  // Change styling
-  DefaultStyle style_default = original_default;
-  ComponentStyle style_slider = original_slider;
-  ComponentStyle style_toggle = original_toggle;
-  style_default.text_size = font_size;
-  ApplyColor(style_slider, color);
-  ApplyColor(style_toggle, color);
-  SetDefaultStyle(style_default);
-  SetComponentStyle(SLIDER, style_slider);
-  SetComponentStyle(TOGGLE, style_toggle);
-
-  const int state = GuiGetState();
-  if (!enabled || WindowOpen()) {
-    GuiSetState(STATE_DISABLED);
-  }
-  int pressed = GuiToggleSlider(
-      bounds, std::format("{};{}", off_label, on_label).data(), active);
-  if (!enabled || WindowOpen()) {
-    GuiSetState(state);
-  }
-
-  // Restore original styling
-  SetDefaultStyle(original_default);
-  SetComponentStyle(SLIDER, original_slider);
-  SetComponentStyle(TOGGLE, original_toggle);
-
-  return pressed;
-}
-
-auto Gui::DrawMenuToggleSlider(int x, int y, int width, int height,
-                               const std::string &off_label,
-                               const std::string &on_label, int *active,
-                               Color color, bool enabled, int font_size) const
-    -> int {
-  Rectangle bounds = menu_grid.Bounds(x, y, width, height);
-  return DrawToggleSlider(bounds, off_label, on_label, active, color, enabled,
-                          font_size);
-};
-
-auto Gui::DrawSpinner(Rectangle bounds, const std::string &label, int *value,
-                      int min, int max, Color color, bool enabled,
-                      int font_size) const -> int {
-  // Save original styling
-  const DefaultStyle original_default = GetDefaultStyle();
-  const ComponentStyle original_valuebox = GetComponentStyle(VALUEBOX);
-  const ComponentStyle original_button = GetComponentStyle(BUTTON);
-
-  // Change styling
-  DefaultStyle style_default = original_default;
-  ComponentStyle style_valuebox = original_valuebox;
-  ComponentStyle style_button = original_button;
-  style_default.text_size = font_size;
-  ApplyColor(style_valuebox, color);
-  ApplyColor(style_button, color);
-  SetDefaultStyle(style_default);
-  SetComponentStyle(VALUEBOX, style_valuebox);
-  SetComponentStyle(BUTTON, style_button);
-
-  const int state = GuiGetState();
-  if (!enabled || WindowOpen()) {
-    GuiSetState(STATE_DISABLED);
-  }
-  int pressed = GuiSpinner(bounds, "", label.data(), value, min, max, false);
-  if (!enabled || WindowOpen()) {
-    GuiSetState(state);
-  }
-
-  // Restore original styling
-  SetDefaultStyle(original_default);
-  SetComponentStyle(VALUEBOX, original_valuebox);
-  SetComponentStyle(BUTTON, style_button);
-
-  return pressed;
-}
-
-auto Gui::DrawMenuSpinner(int x, int y, int width, int height,
-                          const std::string &label, int *value, int min,
-                          int max, Color color, bool enabled,
-                          int font_size) const -> int {
-  Rectangle bounds = menu_grid.Bounds(x, y, width, height);
-  return DrawSpinner(bounds, label, value, min, max, color, enabled, font_size);
-}
-
-auto Gui::DrawLabel(Rectangle bounds, const std::string &text, Color color,
-                    bool enabled, int font_size) const -> int {
-  // Save original styling
-  const DefaultStyle original_default = GetDefaultStyle();
-  const ComponentStyle original_label = GetComponentStyle(LABEL);
-
-  // Change styling
-  DefaultStyle style_default = original_default;
-  ComponentStyle style_label = original_label;
-  style_default.text_size = font_size;
-  ApplyTextColor(style_label, color);
-  SetDefaultStyle(style_default);
-  SetComponentStyle(LABEL, style_label);
-
-  const int state = GuiGetState();
-  if (!enabled || WindowOpen()) {
-    GuiSetState(STATE_DISABLED);
-  }
-  int pressed = GuiLabel(bounds, text.data());
-  if (!enabled || WindowOpen()) {
-    GuiSetState(state);
-  }
-
-  // Restore original styling
-  SetDefaultStyle(original_default);
-  SetComponentStyle(LABEL, original_label);
-
-  return pressed;
-}
-
-auto Gui::DrawBoardBlock(int x, int y, int width, int height, Color color,
-                         bool enabled) const -> bool {
-  ComponentStyle style = GetComponentStyle(BUTTON);
-  ApplyBlockColor(style, color);
-
-  Rectangle bounds = board_grid.SquareBounds(x, y, width, height);
-
-  bool focused =
-      CheckCollisionPointRec(input.mouse - Vector2(0, MENU_HEIGHT), bounds);
-  bool pressed =
-      Block(x, y, width, height, false).Covers(input.sel_x, input.sel_y);
-
-  // Background to make faded colors work
-  DrawRectangleRec(bounds, RAYWHITE);
-
-  Color base = GetColor(style.base_color_normal);
-  Color border = GetColor(style.base_color_normal);
-  if (pressed) {
-    base = GetColor(style.base_color_pressed);
-    border = GetColor(style.base_color_pressed);
-  }
-  if (focused) {
-    base = GetColor(style.base_color_focused);
-    border = GetColor(style.base_color_focused);
-  }
-  if (focused && IsMouseButtonDown(MOUSE_BUTTON_LEFT)) {
-    base = GetColor(style.base_color_pressed);
-    border = GetColor(style.base_color_pressed);
-  }
-  if (!enabled) {
-    base = BOARD_COLOR_RESTRICTED;
-  }
-  DrawRectangleRec(bounds, base);
-  if (enabled) {
-    DrawRectangleLinesEx(bounds, 2.0, border);
-  }
-
-  return focused && enabled;
-}
-
-auto Gui::WindowOpen() const -> bool { return save_window || help_window; }
-
-auto Gui::DrawMenuHeader(Color color) const -> void {
-  int preset = state.current_preset;
-  DrawMenuSpinner(0, 0, 1, 1, "Preset: ", &preset, -1, state.presets.size(),
-                  color, !input.editing);
-  if (preset > state.current_preset) {
-    input.NextPreset();
-  } else if (preset < state.current_preset) {
-    input.PreviousPreset();
-  }
-
-  DrawMenuButton(1, 0, 1, 1,
-                 std::format("Puzzle: \"{}\"",
-                             state.comments.at(state.current_preset).substr(2)),
-                 color, false);
-
-  int editing = input.editing;
-  DrawMenuToggleSlider(2, 0, 1, 1, "Puzzle Mode (Tab)", "Edit Mode (Tab)",
-                       &editing, color);
-  if (editing != input.editing) {
-    input.ToggleEditing();
-  }
-}
-
-auto Gui::DrawGraphInfo(Color color) const -> void {
-  DrawMenuButton(0, 1, 1, 1,
-                 std::format("Found {} States ({} Winning)",
-                             state.states.size(), state.winning_states.size()),
-                 color, false);
-
-  DrawMenuButton(1, 1, 1, 1,
-                 std::format("Found {} Transitions", state.springs.size()),
-                 color, false);
-
-  DrawMenuButton(2, 1, 1, 1,
-                 std::format("{} Moves to Nearest Solution",
-                             state.winning_path.size() > 0
-                                 ? state.winning_path.size() - 1
-                                 : 0),
-                 color, false);
-}
-
-auto Gui::DrawGraphControls(Color color) const -> void {
-  if (DrawMenuButton(1, 2, 1, 1, "Populate Graph (G)", color)) {
-    input.FillGraph();
-  }
-
-  int mark_path = input.mark_path;
-  DrawMenuToggleSlider(2, 2, 1, 1, "Path Hidden (U)", "Path Shown (U)",
-                       &mark_path, color);
-  if (mark_path != input.mark_path) {
-    input.ToggleMarkPath();
-  }
-
-  if (DrawMenuButton(1, 3, 1, 1, "Clear Graph (C)", color)) {
-    input.ClearGraph();
-  }
-
-  int mark_solutions = input.mark_solutions;
-  DrawMenuToggleSlider(2, 3, 1, 1, "Solutions Hidden (I)",
-                       "Solutions Shown (I)", &mark_solutions, color);
-  if (mark_solutions != input.mark_solutions) {
-    input.ToggleMarkSolutions();
-  }
-}
-
-auto Gui::DrawCameraControls(Color color) const -> void {
-  int lock_camera = input.camera_lock;
-  DrawMenuToggleSlider(0, 2, 1, 1, "Free Camera (L)", "Locked Camera (L)",
-                       &lock_camera, color);
-  if (lock_camera != input.camera_lock) {
-    input.ToggleCameraLock();
-  }
-
-  int projection = camera.projection == CAMERA_ORTHOGRAPHIC;
-  DrawMenuToggleSlider(0, 3, 1, 1, "Perspective (Alt)", "Orthographic (Alt)",
-                       &projection, color);
-  if (projection != camera.projection == CAMERA_ORTHOGRAPHIC) {
-    input.ToggleCameraProjection();
-  }
-}
-
-auto Gui::DrawPuzzleControls(Color color) const -> void {
-  auto nth = [&](int n) {
-    if (n == 11 || n == 12 || n == 13)
-      return "th";
-    if (n % 10 == 1)
-      return "st";
-    if (n % 10 == 2)
-      return "nd";
-    if (n % 10 == 3)
-      return "rd";
-    return "th";
-  };
-  int visits = state.visited_states.at(state.current_state);
-  DrawMenuButton(0, 4, 1, 1,
-                 std::format("{} Moves ({}{} Time at this State)",
-                             state.total_moves, visits, nth(visits)),
-                 color, false);
-
-  if (DrawMenuButton(1, 4, 1, 1, "Make Optimal Move (Space)", color)) {
-    input.MakeOptimalMove();
-  }
-
-  if (DrawMenuButton(2, 4, 1, 1, "Undo Last Move (Backspace)", color)) {
-    input.UndoLastMove();
-  }
-
-  if (DrawMenuButton(0, 5, 1, 1, "Go to Nearest Solution (B)", color)) {
-    input.GoToNearestTarget();
-  }
-
-  if (DrawMenuButton(1, 5, 1, 1, "Go to Worst State (V)", color)) {
-    input.GoToWorstState();
-  }
-
-  if (DrawMenuButton(2, 5, 1, 1, "Go to Starting State (R)", color)) {
-    input.ResetState();
-  }
-}
-
-auto Gui::DrawEditControls(Color color) const -> void {
-  // Toggle Target Block
-  if (DrawMenuButton(0, 4, 1, 1, "Toggle Target Block (T)", color)) {
-    input.ToggleTargetBlock();
-  }
-
-  // Toggle Wall Block
-  if (DrawMenuButton(0, 5, 1, 1, "Toggle Wall Block (Y)", color)) {
-    input.ToggleWallBlock();
-  }
-
-  // Toggle Restricted/Free Block Movement
-  int free = !state.current_state.restricted;
-  DrawMenuToggleSlider(1, 4, 1, 1, "Restricted (F)", "Free (F)", &free, color);
-  if (free != !state.current_state.restricted) {
-    input.ToggleRestrictedMovement();
-  }
-
-  // Clear Goal
-  if (DrawMenuButton(1, 5, 1, 1, "Clear Goal (X)", color)) {
-  }
-
-  // Column Count Spinner
-  int columns = state.current_state.width;
-  DrawMenuSpinner(2, 4, 1, 1, "Cols: ", &columns, 1, 9, color);
-  if (columns > state.current_state.width) {
-    input.AddBoardColumn();
-  } else if (columns < state.current_state.width) {
-    input.RemoveBoardColumn();
-  }
-
-  // Row Count Spinner
-  int rows = state.current_state.height;
-  DrawMenuSpinner(2, 5, 1, 1, "Rows: ", &rows, 1, 9, color);
-  if (rows > state.current_state.height) {
-    input.AddBoardRow();
-  } else if (rows < state.current_state.height) {
-    input.RemoveBoardRow();
-  }
-}
-
-auto Gui::DrawMenuFooter(Color color) -> void {
-  DrawMenuButton(0, 6, 2, 1,
-                 std::format("State: \"{}\"", state.current_state.state), color,
-                 false);
-
-  if (DrawMenuButton(2, 6, 1, 1, "Save as Preset", color)) {
-    save_window = true;
-  }
-}
-
-auto Gui::GetBackgroundColor() const -> Color {
-  return GetColor(GuiGetStyle(DEFAULT, BACKGROUND_COLOR));
-}
-
-auto Gui::HelpPopup() -> void {}
-
-auto Gui::DrawSavePresetPopup() -> void {
-  if (!save_window) {
-    return;
-  }
-
-  int width = 450;
-  int height = 150;
-  // Returns the pressed button index
-  int button = GuiTextInputBox(Rectangle((GetScreenWidth() - width) / 2.0,
-                                         (GetScreenHeight() - height) / 2.0,
-                                         width, height),
-                               "Save as Preset", "Enter Preset Name",
-                               "Ok;Cancel", preset_name.data(), 255, NULL);
-  if (button == 1) {
-    state.AppendPresetFile(preset_name.data());
-  }
-  if ((button == 0) || (button == 1) || (button == 2)) {
-    save_window = false;
-    TextCopy(preset_name.data(), "\0");
-  }
-}
-
-auto Gui::DrawMainMenu() -> void {
-  menu_grid.UpdateBounds(0, 0, GetScreenWidth(), MENU_HEIGHT);
-
-  DrawMenuHeader(GRAY);
-  DrawGraphInfo(ORANGE);
-  DrawGraphControls(RED);
-  DrawCameraControls(DARKGREEN);
-
-  if (input.editing) {
-    DrawEditControls(PURPLE);
-  } else {
-    DrawPuzzleControls(BLUE);
-  }
-
-  DrawMenuFooter(GRAY);
-}
-
-auto Gui::DrawPuzzleBoard() -> void {
-  board_grid.UpdateBounds(
-      0, MENU_HEIGHT, GetScreenWidth() / 2, GetScreenHeight() - MENU_HEIGHT,
-      state.current_state.width, state.current_state.height);
-
-  // Draw outer border
-  Rectangle bounds = board_grid.SquareBounds();
-  DrawRectangleRec(bounds, state.current_state.IsWon()
-                               ? BOARD_COLOR_WON
-                               : BOARD_COLOR_RESTRICTED);
-
-  // Draw inner borders
-  DrawRectangle(bounds.x + BOARD_PADDING, bounds.y + BOARD_PADDING,
-                bounds.width - 2 * BOARD_PADDING,
-                bounds.height - 2 * BOARD_PADDING,
-                state.current_state.restricted ? BOARD_COLOR_RESTRICTED
-                                               : BOARD_COLOR_FREE);
-
-  // Draw target opening
-  if (state.current_state.HasWinCondition()) {
-    int target_x = state.current_state.target_x;
-    int target_y = state.current_state.target_y;
-    Block target_block = state.current_state.GetTargetBlock();
-    Rectangle target_bounds = board_grid.SquareBounds(
-        target_x, target_y, target_block.width, target_block.height);
-
-    Color opening_color = Fade(
-        state.current_state.IsWon() ? BOARD_COLOR_WON : BOARD_COLOR_RESTRICTED,
-        0.3);
-
-    if (target_x == 0) {
-
-      // Left opening
-      DrawRectangle(target_bounds.x - BOARD_PADDING, target_bounds.y,
-                    BOARD_PADDING, target_bounds.height, RAYWHITE);
-      DrawRectangle(target_bounds.x - BOARD_PADDING, target_bounds.y,
-                    BOARD_PADDING, target_bounds.height, opening_color);
-    }
-    if (target_x + target_block.width == state.current_state.width) {
-
-      // Right opening
-      DrawRectangle(target_bounds.x + target_bounds.width, target_bounds.y,
-                    BOARD_PADDING, target_bounds.height, RAYWHITE);
-      DrawRectangle(target_bounds.x + target_bounds.width, target_bounds.y,
-                    BOARD_PADDING, target_bounds.height, opening_color);
-    }
-    if (target_y == 0) {
-
-      // Top opening
-      DrawRectangle(target_bounds.x, target_bounds.y - BOARD_PADDING,
-                    target_bounds.width, BOARD_PADDING, RAYWHITE);
-      DrawRectangle(target_bounds.x, target_bounds.y - BOARD_PADDING,
-                    target_bounds.width, BOARD_PADDING, opening_color);
-    }
-    if (target_y + target_block.height == state.current_state.height) {
-
-      // Bottom opening
-      DrawRectangle(target_bounds.x, target_bounds.y + target_bounds.height,
-                    target_bounds.width, BOARD_PADDING, RAYWHITE);
-      DrawRectangle(target_bounds.x, target_bounds.y + target_bounds.height,
-                    target_bounds.width, BOARD_PADDING, opening_color);
-    }
-  }
-
-  // Draw empty cells. Also set hovered blocks
-  input.hov_x = -1;
-  input.hov_y = -1;
-  for (int x = 0; x < board_grid.columns; ++x) {
-    for (int y = 0; y < board_grid.rows; ++y) {
-      DrawRectangleRec(board_grid.SquareBounds(x, y, 1, 1), RAYWHITE);
-
-      Rectangle hov_bounds = board_grid.SquareBounds(x, y, 1, 1);
-      hov_bounds.x -= BOARD_PADDING;
-      hov_bounds.y -= BOARD_PADDING;
-      hov_bounds.width += BOARD_PADDING;
-      hov_bounds.height += BOARD_PADDING;
-      if (CheckCollisionPointRec(GetMousePosition() - Vector2(0, MENU_HEIGHT),
-                                 hov_bounds)) {
-        input.hov_x = x;
-        input.hov_y = y;
-      }
-    }
-  }
-
-  // Draw blocks
-  for (const Block &block : state.current_state) {
-    Color c = BLOCK_COLOR;
-    if (block.target) {
-      c = TARGET_BLOCK_COLOR;
-    } else if (block.immovable) {
-      c = WALL_COLOR;
-    }
-
-    DrawBoardBlock(block.x, block.y, block.width, block.height, c,
-                   !block.immovable);
-  }
-
-  // Draw block placing
-  if (input.editing && input.has_block_add_xy) {
-    if (input.hov_x >= 0 && input.hov_x < state.current_state.width &&
-        input.hov_y >= 0 && input.hov_y < state.current_state.height &&
-        input.hov_x >= input.block_add_x && input.hov_y >= input.block_add_y) {
-      bool collides = false;
-      for (const Block &block : state.current_state) {
-        if (block.Collides(Block(input.block_add_x, input.block_add_y,
-                                 input.hov_x - input.block_add_x + 1,
-                                 input.hov_y - input.block_add_y + 1, false))) {
-          collides = true;
-          break;
-        }
-      }
-      if (!collides) {
-        DrawBoardBlock(input.block_add_x, input.block_add_y,
-                       input.hov_x - input.block_add_x + 1,
-                       input.hov_y - input.block_add_y + 1, PURPLE, false);
-      }
-    }
-  }
-}
-
-auto Gui::DrawGraphOverlay(int fps, int ups) -> void {
-  graph_overlay_grid.UpdateBounds(GetScreenWidth() / 2, MENU_HEIGHT);
-
-  DrawLabel(graph_overlay_grid.Bounds(0, 0, 1, 1),
-            std::format("Dist: {:0>7.2f}", camera.distance), BLACK);
-  DrawLabel(graph_overlay_grid.Bounds(0, 1, 1, 1),
-            std::format("FoV:  {:0>6.2f}", camera.fov), BLACK);
-  DrawLabel(graph_overlay_grid.Bounds(0, 2, 1, 1),
-            std::format("FPS:  {:0>3}", fps), LIME);
-  DrawLabel(graph_overlay_grid.Bounds(0, 3, 1, 1),
-            std::format("UPS:  {:0>3}", ups), ORANGE);
-}
-
-auto Gui::Update() -> void { input.disable = WindowOpen(); }

src/input.cpp

@@ -1,483 +0,0 @@
-#include "input.hpp"
-#include "config.hpp"
-
-#include <algorithm>
-#include <print>
-#include <raylib.h>
-
-#ifdef TRACY
-#include "tracy.hpp"
-#include <tracy/Tracy.hpp>
-#endif
-
-auto InputHandler::InitHandlers() -> void {
-  // The order matters if multiple handlers are registered to the same key
-
-  RegisterGenericHandler(&InputHandler::CameraPan);
-  RegisterGenericHandler(&InputHandler::CameraRotate);
-  RegisterGenericHandler(&InputHandler::CameraZoom);
-  RegisterGenericHandler(&InputHandler::CameraFov);
-  RegisterGenericHandler(&InputHandler::MouseHover);
-
-  RegisterMousePressedHandler(MOUSE_BUTTON_LEFT, &InputHandler::CameraStartPan);
-  RegisterMousePressedHandler(MOUSE_BUTTON_LEFT, &InputHandler::SelectBlock);
-  RegisterMousePressedHandler(MOUSE_BUTTON_LEFT, &InputHandler::AddBlock);
-  RegisterMousePressedHandler(MOUSE_BUTTON_LEFT, &InputHandler::StartAddBlock);
-  RegisterMousePressedHandler(MOUSE_BUTTON_RIGHT,
-                              &InputHandler::CameraStartRotate);
-  RegisterMousePressedHandler(MOUSE_BUTTON_RIGHT, &InputHandler::RemoveBlock);
-  RegisterMousePressedHandler(MOUSE_BUTTON_RIGHT, &InputHandler::ClearAddBlock);
-  RegisterMousePressedHandler(MOUSE_BUTTON_MIDDLE, &InputHandler::PlaceGoal);
-
-  RegisterMouseReleasedHandler(MOUSE_BUTTON_LEFT, &InputHandler::CameraStopPan);
-  RegisterMouseReleasedHandler(MOUSE_BUTTON_RIGHT,
-                               &InputHandler::CameraStopRotate);
-
-  RegisterKeyPressedHandler(KEY_W, &InputHandler::MoveBlockNor);
-  RegisterKeyPressedHandler(KEY_D, &InputHandler::MoveBlockEas);
-  RegisterKeyPressedHandler(KEY_S, &InputHandler::MoveBlockSou);
-  RegisterKeyPressedHandler(KEY_A, &InputHandler::MoveBlockWes);
-  RegisterKeyPressedHandler(KEY_P, &InputHandler::PrintState);
-  RegisterKeyPressedHandler(KEY_N, &InputHandler::PreviousPreset);
-  RegisterKeyPressedHandler(KEY_M, &InputHandler::NextPreset);
-  RegisterKeyPressedHandler(KEY_R, &InputHandler::ResetState);
-  RegisterKeyPressedHandler(KEY_G, &InputHandler::FillGraph);
-  RegisterKeyPressedHandler(KEY_C, &InputHandler::ClearGraph);
-  RegisterKeyPressedHandler(KEY_I, &InputHandler::ToggleMarkSolutions);
-  RegisterKeyPressedHandler(KEY_O, &InputHandler::ToggleConnectSolutions);
-  RegisterKeyPressedHandler(KEY_U, &InputHandler::ToggleMarkPath);
-  RegisterKeyPressedHandler(KEY_SPACE, &InputHandler::MakeOptimalMove);
-  RegisterKeyPressedHandler(KEY_V, &InputHandler::GoToWorstState);
-  RegisterKeyPressedHandler(KEY_B, &InputHandler::GoToNearestTarget);
-  RegisterKeyPressedHandler(KEY_BACKSPACE, &InputHandler::UndoLastMove);
-  RegisterKeyPressedHandler(KEY_F, &InputHandler::ToggleRestrictedMovement);
-  RegisterKeyPressedHandler(KEY_T, &InputHandler::ToggleTargetBlock);
-  RegisterKeyPressedHandler(KEY_Y, &InputHandler::ToggleWallBlock);
-  RegisterKeyPressedHandler(KEY_UP, &InputHandler::AddBoardRow);
-  RegisterKeyPressedHandler(KEY_RIGHT, &InputHandler::AddBoardColumn);
-  RegisterKeyPressedHandler(KEY_DOWN, &InputHandler::RemoveBoardRow);
-  RegisterKeyPressedHandler(KEY_LEFT, &InputHandler::RemoveBoardColumn);
-  RegisterKeyPressedHandler(KEY_TAB, &InputHandler::ToggleEditing);
-  RegisterKeyPressedHandler(KEY_L, &InputHandler::ToggleCameraLock);
-  RegisterKeyPressedHandler(KEY_LEFT_ALT,
-                            &InputHandler::ToggleCameraProjection);
-  RegisterKeyPressedHandler(KEY_X, &InputHandler::ClearGoal);
-}
-
-auto InputHandler::MouseInMenuPane() -> bool { return mouse.y < MENU_HEIGHT; }
-
-auto InputHandler::MouseInBoardPane() -> bool {
-  return mouse.x < GetScreenWidth() / 2.0 && mouse.y >= MENU_HEIGHT;
-}
-
-auto InputHandler::MouseInGraphPane() -> bool {
-  return mouse.x >= GetScreenWidth() / 2.0 && mouse.y >= MENU_HEIGHT;
-}
-
-auto InputHandler::MouseHover() -> void {
-  last_mouse = mouse;
-  mouse = GetMousePosition();
-}
-
-auto InputHandler::CameraStartPan() -> void {
-  if (!MouseInGraphPane()) {
-    return;
-  }
-
-  camera_panning = true;
-  // Enable this if the camera should be pannable even when locked (releasing
-  // the lock in the process):
-  // camera_lock = false;
-}
-
-auto InputHandler::CameraPan() -> void {
-  if (camera_panning) {
-    camera.Pan(last_mouse, mouse);
-  }
-}
-
-auto InputHandler::CameraStopPan() -> void { camera_panning = false; }
-
-auto InputHandler::CameraStartRotate() -> void {
-  if (!MouseInGraphPane()) {
-    return;
-  }
-
-  camera_rotating = true;
-}
-
-auto InputHandler::CameraRotate() -> void {
-  if (camera_rotating) {
-    camera.Rotate(last_mouse, mouse);
-  }
-}
-
-auto InputHandler::CameraStopRotate() -> void { camera_rotating = false; }
-
-auto InputHandler::CameraZoom() -> void {
-  if (!MouseInGraphPane() || IsKeyDown(KEY_LEFT_CONTROL)) {
-    return;
-  }
-
-  float wheel = GetMouseWheelMove();
-
-  if (IsKeyDown(KEY_LEFT_SHIFT)) {
-    camera.distance -= wheel * ZOOM_SPEED * ZOOM_MULTIPLIER;
-  } else {
-    camera.distance -= wheel * ZOOM_SPEED;
-  }
-}
-
-auto InputHandler::CameraFov() -> void {
-  if (!MouseInGraphPane() || !IsKeyDown(KEY_LEFT_CONTROL) ||
-      IsKeyDown(KEY_LEFT_SHIFT)) {
-    return;
-  }
-
-  float wheel = GetMouseWheelMove();
-  camera.fov -= wheel * FOV_SPEED;
-}
-
-auto InputHandler::ToggleCameraLock() -> void {
-  if (!camera_lock) {
-    camera_panning = false;
-  }
-
-  camera_lock = !camera_lock;
-}
-
-auto InputHandler::ToggleCameraProjection() -> void {
-  camera.projection = camera.projection == CAMERA_PERSPECTIVE
-                          ? CAMERA_ORTHOGRAPHIC
-                          : CAMERA_PERSPECTIVE;
-}
-
-auto InputHandler::SelectBlock() -> void {
-  if (state.current_state.GetBlock(hov_x, hov_y).IsValid()) {
-    sel_x = hov_x;
-    sel_y = hov_y;
-  }
-}
-
-auto InputHandler::StartAddBlock() -> void {
-  if (!editing || state.current_state.GetBlock(hov_x, hov_y).IsValid() ||
-      has_block_add_xy) {
-    return;
-  }
-
-  if (hov_x >= 0 && hov_x < state.current_state.width && hov_y >= 0 &&
-      hov_y < state.current_state.height) {
-    block_add_x = hov_x;
-    block_add_y = hov_y;
-    has_block_add_xy = true;
-  }
-}
-
-auto InputHandler::ClearAddBlock() -> void {
-  if (!editing || !has_block_add_xy) {
-    return;
-  }
-
-  block_add_x = -1;
-  block_add_y = -1;
-  has_block_add_xy = false;
-}
-
-auto InputHandler::AddBlock() -> void {
-  if (!editing || state.current_state.GetBlock(hov_x, hov_y).IsValid() ||
-      !has_block_add_xy) {
-    return;
-  }
-
-  int block_add_width = hov_x - block_add_x + 1;
-  int block_add_height = hov_y - block_add_y + 1;
-  if (block_add_width <= 0 || block_add_height <= 0) {
-    block_add_x = -1;
-    block_add_y = -1;
-    has_block_add_xy = false;
-  } else if (block_add_x >= 0 &&
-             block_add_x + block_add_width <= state.current_state.width &&
-             block_add_y >= 0 &&
-             block_add_y + block_add_height <= state.current_state.height) {
-    bool success = state.current_state.AddBlock(Block(
-        block_add_x, block_add_y, block_add_width, block_add_height, false));
-
-    if (success) {
-      sel_x = block_add_x;
-      sel_y = block_add_y;
-      block_add_x = -1;
-      block_add_y = -1;
-      has_block_add_xy = false;
-      state.ClearGraph();
-      state.edited = true;
-    }
-  }
-}
-
-auto InputHandler::RemoveBlock() -> void {
-  Block block = state.current_state.GetBlock(hov_x, hov_y);
-  if (!editing || has_block_add_xy || !block.IsValid() ||
-      !state.current_state.RemoveBlock(hov_x, hov_y)) {
-    return;
-  }
-
-  if (block.Covers(sel_x, sel_y)) {
-    sel_x = 0;
-    sel_y = 0;
-  }
-
-  state.ClearGraph();
-  state.edited = true;
-}
-
-auto InputHandler::PlaceGoal() -> void {
-  if (!editing || hov_x < 0 || hov_x >= state.current_state.width ||
-      hov_y < 0 || hov_y >= state.current_state.height) {
-    return;
-  }
-
-  if (state.current_state.SetGoal(hov_x, hov_y)) {
-    // We can't just call state.FindWinningStates() because the
-    // state is entirely different if it has a different win condition.
-    state.ClearGraph();
-  }
-}
-
-auto InputHandler::MoveBlockNor() -> void {
-  if (state.current_state.MoveBlockAt(sel_x, sel_y, Direction::NOR)) {
-    sel_y--;
-  }
-}
-
-auto InputHandler::MoveBlockEas() -> void {
-  if (state.current_state.MoveBlockAt(sel_x, sel_y, Direction::EAS)) {
-    sel_x++;
-  }
-}
-
-auto InputHandler::MoveBlockSou() -> void {
-  if (state.current_state.MoveBlockAt(sel_x, sel_y, Direction::SOU)) {
-    sel_y++;
-  }
-}
-
-auto InputHandler::MoveBlockWes() -> void {
-  if (state.current_state.MoveBlockAt(sel_x, sel_y, Direction::WES)) {
-    sel_x--;
-  }
-}
-
-auto InputHandler::PrintState() const -> void {
-  std::println("State: \"{}\"", state.current_state.state);
-  Block sel = state.current_state.GetBlock(sel_x, sel_y);
-  int idx = state.current_state.GetIndex(sel.x, sel.y) - State::prefix;
-  if (sel.IsValid()) {
-    std::println("Sel:   \"{}{}{}{}\"",
-                 state.current_state.state.substr(0, State::prefix),
-                 std::string(idx, '.'), sel.ToString(),
-                 std::string(state.current_state.state.length() - idx -
-                                 State::prefix - 2,
-                             '.'));
-  }
-}
-
-auto InputHandler::PreviousPreset() -> void {
-  if (editing) {
-    return;
-  }
-
-  block_add_x = -1;
-  block_add_y = -1;
-  has_block_add_xy = false;
-  state.PreviousPreset();
-}
-
-auto InputHandler::NextPreset() -> void {
-  if (editing) {
-    return;
-  }
-
-  block_add_x = -1;
-  block_add_y = -1;
-  has_block_add_xy = false;
-  state.NextPreset();
-}
-
-auto InputHandler::ResetState() -> void {
-  if (editing) {
-    return;
-  }
-
-  state.ResetState();
-}
-
-auto InputHandler::FillGraph() -> void { state.FillGraph(); }
-
-auto InputHandler::ClearGraph() -> void { state.ClearGraph(); }
-
-auto InputHandler::ToggleMarkSolutions() -> void {
-  mark_solutions = !mark_solutions;
-}
-
-auto InputHandler::ToggleConnectSolutions() -> void {
-  connect_solutions = !connect_solutions;
-}
-
-auto InputHandler::ToggleMarkPath() -> void { mark_path = !mark_path; }
-
-auto InputHandler::MakeOptimalMove() -> void { state.NextPath(); }
-
-auto InputHandler::GoToWorstState() -> void { state.GoToWorst(); }
-
-auto InputHandler::GoToNearestTarget() -> void { state.GoToNearestTarget(); }
-
-auto InputHandler::UndoLastMove() -> void { state.PopHistory(); }
-
-auto InputHandler::ToggleRestrictedMovement() -> void {
-  if (!editing) {
-    return;
-  }
-
-  state.current_state.ToggleRestricted();
-  state.ClearGraph();
-  state.edited = true;
-}
-
-auto InputHandler::ToggleTargetBlock() -> void {
-  if (!editing) {
-    return;
-  }
-
-  state.current_state.ToggleTarget(sel_x, sel_y);
-  state.ClearGraph();
-  state.edited = true;
-}
-
-auto InputHandler::ToggleWallBlock() -> void {
-  if (!editing) {
-    return;
-  }
-
-  state.current_state.ToggleWall(sel_x, sel_y);
-  state.ClearGraph();
-  state.edited = true;
-}
-
-auto InputHandler::RemoveBoardColumn() -> void {
-  if (!editing || state.current_state.width <= 1) {
-    return;
-  }
-
-  state.current_state = state.current_state.RemoveColumn();
-  state.ClearGraph();
-  state.edited = true;
-}
-
-auto InputHandler::AddBoardColumn() -> void {
-  if (!editing || state.current_state.width >= 9) {
-    return;
-  }
-
-  state.current_state = state.current_state.AddColumn();
-  state.ClearGraph();
-  state.edited = true;
-}
-
-auto InputHandler::RemoveBoardRow() -> void {
-  if (!editing || state.current_state.height <= 1) {
-    return;
-  }
-
-  state.current_state = state.current_state.RemoveRow();
-  state.ClearGraph();
-  state.edited = true;
-}
-
-auto InputHandler::AddBoardRow() -> void {
-  if (!editing || state.current_state.height >= 9) {
-    return;
-  }
-
-  state.current_state = state.current_state.AddRow();
-  state.ClearGraph();
-  state.edited = true;
-}
-
-auto InputHandler::ToggleEditing() -> void {
-  if (editing) {
-    has_block_add_xy = false;
-    block_add_x = -1;
-    block_add_y = -1;
-  }
-
-  editing = !editing;
-}
-
-auto InputHandler::ClearGoal() -> void {
-  if (!editing) {
-    return;
-  }
-
-  state.current_state.ClearGoal();
-  state.ClearGraph();
-  state.edited = true;
-}
-
-auto InputHandler::RegisterGenericHandler(
-    std::function<void(InputHandler &)> handler) -> void {
-  generic_handlers.push_back({handler});
-}
-
-auto InputHandler::RegisterMousePressedHandler(
-    MouseButton button, std::function<void(InputHandler &)> handler) -> void {
-  mouse_pressed_handlers.push_back({handler, button});
-}
-
-auto InputHandler::RegisterMouseReleasedHandler(
-    MouseButton button, std::function<void(InputHandler &)> handler) -> void {
-  mouse_released_handlers.push_back({handler, button});
-}
-
-auto InputHandler::RegisterKeyPressedHandler(
-    KeyboardKey key, std::function<void(InputHandler &)> handler) -> void {
-  key_pressed_handlers.push_back({handler, key});
-}
-
-auto InputHandler::RegisterKeyReleasedHandler(
-    KeyboardKey key, std::function<void(InputHandler &)> handler) -> void {
-  key_released_handlers.push_back({handler, key});
-}
-
-auto InputHandler::HandleInput() -> void {
-  if (disable) {
-    return;
-  }
-
-  for (const GenericHandler &handler : generic_handlers) {
-    handler.handler(*this);
-  }
-
-  for (const MouseHandler &handler : mouse_pressed_handlers) {
-    if (IsMouseButtonPressed(handler.button)) {
-      handler.handler(*this);
-    }
-  }
-
-  for (const MouseHandler &handler : mouse_released_handlers) {
-    if (IsMouseButtonReleased(handler.button)) {
-      handler.handler(*this);
-    }
-  }
-
-  for (const KeyboardHandler &handler : key_pressed_handlers) {
-    if (IsKeyPressed(handler.key)) {
-      handler.handler(*this);
-    }
-  }
-
-  for (const KeyboardHandler &handler : key_released_handlers) {
-    if (IsKeyReleased(handler.key)) {
-      handler.handler(*this);
-    }
-  }
-}

src/input_handler.cpp

@@ -0,0 +1,617 @@
+#include "input_handler.hpp"
+#include "config.hpp"
+
+#include <raylib.h>
+
+auto input_handler::init_handlers() -> void
+{
+    // The order matters if multiple handlers are registered to the same key
+
+    register_generic_handler(&input_handler::camera_pan);
+    register_generic_handler(&input_handler::camera_rotate);
+    register_generic_handler(&input_handler::camera_zoom);
+    register_generic_handler(&input_handler::camera_fov);
+    register_generic_handler(&input_handler::mouse_hover);
+
+    register_mouse_pressed_handler(MOUSE_BUTTON_LEFT, &input_handler::camera_start_pan);
+    register_mouse_pressed_handler(MOUSE_BUTTON_LEFT, &input_handler::select_block);
+    register_mouse_pressed_handler(MOUSE_BUTTON_LEFT, &input_handler::add_block);
+    register_mouse_pressed_handler(MOUSE_BUTTON_LEFT, &input_handler::start_add_block);
+    register_mouse_pressed_handler(MOUSE_BUTTON_MIDDLE, &input_handler::place_goal);
+    register_mouse_pressed_handler(MOUSE_BUTTON_RIGHT, &input_handler::camera_start_rotate);
+    register_mouse_pressed_handler(MOUSE_BUTTON_RIGHT, &input_handler::remove_block);
+    register_mouse_pressed_handler(MOUSE_BUTTON_RIGHT, &input_handler::clear_add_block);
+
+    register_mouse_released_handler(MOUSE_BUTTON_LEFT, &input_handler::camera_stop_pan);
+    register_mouse_released_handler(MOUSE_BUTTON_RIGHT, &input_handler::camera_stop_rotate);
+
+    register_key_pressed_handler(KEY_W, &input_handler::move_block_nor);
+    register_key_pressed_handler(KEY_D, &input_handler::move_block_eas);
+    register_key_pressed_handler(KEY_S, &input_handler::move_block_sou);
+    register_key_pressed_handler(KEY_A, &input_handler::move_block_wes);
+
+    register_key_pressed_handler(KEY_N, &input_handler::load_previous_preset);
+    register_key_pressed_handler(KEY_M, &input_handler::load_next_preset);
+    register_key_pressed_handler(KEY_R, &input_handler::goto_starting_state);
+    register_key_pressed_handler(KEY_V, &input_handler::goto_most_distant_state);
+    register_key_pressed_handler(KEY_B, &input_handler::goto_closest_target_state);
+    register_key_pressed_handler(KEY_SPACE, &input_handler::goto_optimal_next_state);
+    register_key_pressed_handler(KEY_BACKSPACE, &input_handler::goto_previous_state);
+
+    register_key_pressed_handler(KEY_G, &input_handler::populate_graph);
+    register_key_pressed_handler(KEY_C, &input_handler::clear_graph);
+    register_key_pressed_handler(KEY_I, &input_handler::toggle_mark_solutions);
+    register_key_pressed_handler(KEY_O, &input_handler::toggle_connect_solutions);
+
+    register_key_pressed_handler(KEY_TAB, &input_handler::toggle_editing);
+    register_key_pressed_handler(KEY_F, &input_handler::toggle_restricted_movement);
+    register_key_pressed_handler(KEY_T, &input_handler::toggle_target_block);
+    register_key_pressed_handler(KEY_Y, &input_handler::toggle_wall_block);
+    register_key_pressed_handler(KEY_UP, &input_handler::add_board_row);
+    register_key_pressed_handler(KEY_RIGHT, &input_handler::add_board_column);
+    register_key_pressed_handler(KEY_DOWN, &input_handler::remove_board_row);
+    register_key_pressed_handler(KEY_LEFT, &input_handler::remove_board_column);
+    register_key_pressed_handler(KEY_X, &input_handler::clear_goal);
+    register_key_pressed_handler(KEY_P, &input_handler::print_state);
+    register_key_pressed_handler(KEY_S, &input_handler::save_preset); // + CTRL
+
+    register_key_pressed_handler(KEY_L, &input_handler::toggle_camera_lock);
+    register_key_pressed_handler(KEY_LEFT_ALT, &input_handler::toggle_camera_projection);
+    register_key_pressed_handler(KEY_U, &input_handler::toggle_camera_mass_center_lock);
+}
+
+auto input_handler::mouse_in_menu_pane() const -> bool
+{
+    return mouse.y < MENU_HEIGHT;
+}
+
+auto input_handler::mouse_in_board_pane() const -> bool
+{
+    return mouse.x < GetScreenWidth() / 2.0 && mouse.y >= MENU_HEIGHT;
+}
+
+auto input_handler::mouse_in_graph_pane() const -> bool
+{
+    return mouse.x >= GetScreenWidth() / 2.0 && mouse.y >= MENU_HEIGHT;
+}
+
+auto input_handler::mouse_hover() -> void
+{
+    last_mouse = mouse;
+    mouse = GetMousePosition();
+}
+
+auto input_handler::camera_start_pan() -> void
+{
+    if (!mouse_in_graph_pane()) {
+        return;
+    }
+
+    camera_panning = true;
+    // Enable this if the camera should be pannable even when locked (releasing the lock in the
+    // process): camera_lock = false;
+}
+
+auto input_handler::camera_pan() const -> void
+{
+    if (camera_panning) {
+        camera.pan(last_mouse, mouse);
+    }
+}
+
+auto input_handler::camera_stop_pan() -> void
+{
+    camera_panning = false;
+}
+
+auto input_handler::camera_start_rotate() -> void
+{
+    if (!mouse_in_graph_pane()) {
+        return;
+    }
+
+    camera_rotating = true;
+}
+
+auto input_handler::camera_rotate() const -> void
+{
+    if (camera_rotating) {
+        camera.rotate(last_mouse, mouse);
+    }
+}
+
+auto input_handler::camera_stop_rotate() -> void
+{
+    camera_rotating = false;
+}
+
+auto input_handler::camera_zoom() const -> void
+{
+    if (!mouse_in_graph_pane() || IsKeyDown(KEY_LEFT_CONTROL) || camera.projection == CAMERA_ORTHOGRAPHIC) {
+        return;
+    }
+
+    const float wheel = GetMouseWheelMove();
+
+    if (IsKeyDown(KEY_LEFT_SHIFT)) {
+        camera.distance -= wheel * ZOOM_SPEED * ZOOM_MULTIPLIER;
+    } else {
+        camera.distance -= wheel * ZOOM_SPEED;
+    }
+}
+
+auto input_handler::camera_fov() const -> void
+{
+    if (!mouse_in_graph_pane() || !IsKeyDown(KEY_LEFT_CONTROL) || IsKeyDown(KEY_LEFT_SHIFT)) {
+        return;
+    }
+
+    const float wheel = GetMouseWheelMove();
+    camera.fov -= wheel * FOV_SPEED;
+}
+
+auto input_handler::select_block() -> void
+{
+    const puzzle& current = state.get_current_state();
+    if (current.try_get_block(hov_x, hov_y)) {
+        sel_x = hov_x;
+        sel_y = hov_y;
+    }
+}
+
+auto input_handler::start_add_block() -> void
+{
+    const puzzle& current = state.get_current_state();
+    if (!editing || current.try_get_block(hov_x, hov_y) || has_block_add_xy || current.block_count() >=
+        puzzle::MAX_BLOCKS) {
+        return;
+    }
+
+    if (hov_x >= 0 && hov_x < current.get_width() && hov_y >= 0 && hov_y < current.get_height()) {
+        block_add_x = hov_x;
+        block_add_y = hov_y;
+        has_block_add_xy = true;
+    }
+}
+
+auto input_handler::clear_add_block() -> void
+{
+    if (!editing || !has_block_add_xy) {
+        return;
+    }
+
+    block_add_x = -1;
+    block_add_y = -1;
+    has_block_add_xy = false;
+}
+
+auto input_handler::add_block() -> void
+{
+    const puzzle& current = state.get_current_state();
+    if (!editing || current.try_get_block(hov_x, hov_y) || !has_block_add_xy || current.block_count() >=
+        puzzle::MAX_BLOCKS) {
+        return;
+    }
+
+    const int block_add_width = hov_x - block_add_x + 1;
+    const int block_add_height = hov_y - block_add_y + 1;
+    if (block_add_width <= 0 || block_add_height <= 0) {
+        block_add_x = -1;
+        block_add_y = -1;
+        has_block_add_xy = false;
+    } else if (current.covers(block_add_x, block_add_y, block_add_width, block_add_height)) {
+        const std::optional<puzzle>& next = current.try_add_block(
+            puzzle::block(block_add_x, block_add_y, block_add_width, block_add_height, false));
+
+        if (next) {
+            sel_x = block_add_x;
+            sel_y = block_add_y;
+            block_add_x = -1;
+            block_add_y = -1;
+            has_block_add_xy = false;
+            state.edit_starting_state(*next);
+        }
+    }
+}
+
+auto input_handler::remove_block() -> void
+{
+    const puzzle& current = state.get_current_state();
+    const std::optional<puzzle::block>& b = current.try_get_block(hov_x, hov_y);
+    if (!editing || has_block_add_xy || !b) {
+        return;
+    }
+
+    const std::optional<puzzle>& next = current.try_remove_block(hov_x, hov_y);
+    if (!next) {
+        return;
+    }
+
+    // Reset selection if we removed the selected block
+    if (b->covers(sel_x, sel_y)) {
+        sel_x = 0;
+        sel_y = 0;
+    }
+
+    state.edit_starting_state(*next);
+}
+
+auto input_handler::place_goal() const -> void
+{
+    const puzzle& current = state.get_current_state();
+    if (!editing || !current.covers(hov_x, hov_y)) {
+        return;
+    }
+
+    const std::optional<puzzle>& next = current.try_set_goal(hov_x, hov_y);
+    if (!next) {
+        return;
+    }
+
+    state.edit_starting_state(*next);
+}
+
+auto input_handler::toggle_camera_lock() -> void
+{
+    if (!camera_lock) {
+        camera_panning = false;
+    }
+
+    camera_lock = !camera_lock;
+}
+
+auto input_handler::toggle_camera_mass_center_lock() -> void
+{
+    if (!camera_mass_center_lock) {
+        camera_lock = true;
+        camera_panning = false;
+    }
+
+    camera_mass_center_lock = !camera_mass_center_lock;
+}
+
+auto input_handler::toggle_camera_projection() const -> void
+{
+    camera.projection = camera.projection == CAMERA_PERSPECTIVE ? CAMERA_ORTHOGRAPHIC : CAMERA_PERSPECTIVE;
+}
+
+auto input_handler::move_block_nor() -> void
+{
+    const puzzle& current = state.get_current_state();
+    const std::optional<puzzle>& next = current.try_move_block_at_fast(sel_x, sel_y, nor);
+    if (!next) {
+        return;
+    }
+
+    sel_y--;
+    state.update_current_state(*next);
+}
+
+auto input_handler::move_block_wes() -> void
+{
+    const puzzle& current = state.get_current_state();
+    const std::optional<puzzle>& next = current.try_move_block_at_fast(sel_x, sel_y, wes);
+    if (!next) {
+        return;
+    }
+
+    sel_x--;
+    state.update_current_state(*next);
+}
+
+auto input_handler::move_block_sou() -> void
+{
+    const puzzle& current = state.get_current_state();
+    const std::optional<puzzle>& next = current.try_move_block_at_fast(sel_x, sel_y, sou);
+    if (!next) {
+        return;
+    }
+
+    sel_y++;
+    state.update_current_state(*next);
+}
+
+auto input_handler::move_block_eas() -> void
+{
+    const puzzle& current = state.get_current_state();
+    const std::optional<puzzle>& next = current.try_move_block_at_fast(sel_x, sel_y, eas);
+    if (!next) {
+        return;
+    }
+
+    sel_x++;
+    state.update_current_state(*next);
+}
+
+auto input_handler::print_state() const -> void
+{
+    infoln("State: \"{}\"", state.get_current_state().string_repr());
+}
+
+auto input_handler::load_previous_preset() -> void
+{
+    if (editing) {
+        return;
+    }
+
+    const auto handler = [&]
+    {
+        block_add_x = -1;
+        block_add_y = -1;
+        has_block_add_xy = false;
+        state.load_previous_preset();
+    };
+
+    if (state.was_edited()) {
+        ui_commands.emplace(show_yes_no_message{"Switch Preset?", "Edits Will Be Lost.", handler});
+    } else {
+        handler();
+    }
+}
+
+auto input_handler::load_next_preset() -> void
+{
+    if (editing) {
+        return;
+    }
+
+    const auto handler = [&]
+    {
+        block_add_x = -1;
+        block_add_y = -1;
+        has_block_add_xy = false;
+        state.load_next_preset();
+    };
+
+    if (state.was_edited()) {
+        ui_commands.emplace(show_yes_no_message{"Switch Preset?", "Edits Will Be Lost.", handler});
+    } else {
+        handler();
+    }
+}
+
+auto input_handler::goto_starting_state() -> void
+{
+    const auto handler = [&]
+    {
+        state.goto_starting_state();
+        sel_x = 0;
+        sel_y = 0;
+    };
+
+    ui_commands.emplace(show_yes_no_message{"Reset Board?", "This Clears the Move History.", handler});
+}
+
+auto input_handler::populate_graph() const -> void
+{
+    state.populate_graph();
+}
+
+auto input_handler::clear_graph() -> void
+{
+    const auto handler = [&]
+    {
+        state.clear_graph_and_add_current();
+    };
+
+    ui_commands.emplace(show_yes_no_message{"Clear Graph?", "This Clears the Move History.", handler});
+}
+
+auto input_handler::toggle_mark_solutions() -> void
+{
+    mark_solutions = !mark_solutions;
+}
+
+auto input_handler::toggle_connect_solutions() -> void
+{
+    connect_solutions = !connect_solutions;
+}
+
+auto input_handler::toggle_mark_path() -> void
+{
+    mark_path = !mark_path;
+}
+
+auto input_handler::goto_optimal_next_state() const -> void
+{
+    state.goto_optimal_next_state();
+}
+
+auto input_handler::goto_most_distant_state() const -> void
+{
+    state.goto_most_distant_state();
+}
+
+auto input_handler::goto_closest_target_state() const -> void
+{
+    state.goto_closest_target_state();
+}
+
+auto input_handler::goto_previous_state() const -> void
+{
+    state.goto_previous_state();
+}
+
+auto input_handler::toggle_restricted_movement() const -> void
+{
+    const puzzle& current = state.get_current_state();
+    const std::optional<puzzle>& next = current.toggle_restricted();
+
+    if (!editing || !next) {
+        return;
+    }
+
+    state.edit_starting_state(*next);
+}
+
+auto input_handler::toggle_target_block() const -> void
+{
+    const puzzle& current = state.get_current_state();
+    const std::optional<puzzle>& next = current.try_toggle_target(sel_x, sel_y);
+
+    if (!editing || !next) {
+        return;
+    }
+
+    state.edit_starting_state(*next);
+}
+
+auto input_handler::toggle_wall_block() const -> void
+{
+    const puzzle& current = state.get_current_state();
+    const std::optional<puzzle>& next = current.try_toggle_wall(sel_x, sel_y);
+
+    if (!editing || !next) {
+        return;
+    }
+
+    state.edit_starting_state(*next);
+}
+
+auto input_handler::remove_board_column() const -> void
+{
+    const puzzle& current = state.get_current_state();
+    const std::optional<puzzle>& next = current.try_remove_column();
+
+    if (!editing || current.get_width() <= puzzle::MIN_WIDTH || !next) {
+        return;
+    }
+
+    state.edit_starting_state(*next);
+}
+
+auto input_handler::add_board_column() const -> void
+{
+    const puzzle& current = state.get_current_state();
+    const std::optional<puzzle>& next = current.try_add_column();
+
+    if (!editing || current.get_width() >= puzzle::MAX_WIDTH || !next) {
+        return;
+    }
+
+    state.edit_starting_state(*next);
+}
+
+auto input_handler::remove_board_row() const -> void
+{
+    const puzzle& current = state.get_current_state();
+    const std::optional<puzzle>& next = current.try_remove_row();
+
+    if (!editing || current.get_height() <= puzzle::MIN_HEIGHT || !next) {
+        return;
+    }
+
+    state.edit_starting_state(*next);
+}
+
+auto input_handler::add_board_row() const -> void
+{
+    const puzzle& current = state.get_current_state();
+    const std::optional<puzzle>& next = current.try_add_row();
+
+    if (!editing || current.get_height() >= puzzle::MAX_HEIGHT || !next) {
+        return;
+    }
+
+    state.edit_starting_state(*next);
+}
+
+auto input_handler::toggle_editing() -> void
+{
+    if (editing) {
+        has_block_add_xy = false;
+        block_add_x = -1;
+        block_add_y = -1;
+    }
+
+    editing = !editing;
+}
+
+auto input_handler::clear_goal() const -> void
+{
+    const puzzle& current = state.get_current_state();
+    const std::optional<puzzle>& next = current.clear_goal();
+
+    if (!editing || !next) {
+        return;
+    }
+
+    state.edit_starting_state(*next);
+}
+
+auto input_handler::save_preset() -> void
+{
+    if (!IsKeyDown(KEY_LEFT_CONTROL)) {
+        return;
+    }
+
+    if (const std::optional<std::string>& reason = state.get_current_state().try_get_invalid_reason()) {
+        ui_commands.emplace(show_ok_message{"Can't Save Preset", std::format("Invalid Board: {}.", *reason)});
+    } else {
+        ui_commands.emplace(show_save_preset_window{});
+    }
+}
+
+auto input_handler::register_generic_handler(const std::function<void(input_handler&)>& handler) -> void
+{
+    generic_handlers.push_back({handler});
+}
+
+auto input_handler::register_mouse_pressed_handler(const MouseButton button,
+                                                   const std::function<void(input_handler&)>& handler) -> void
+{
+    mouse_pressed_handlers.push_back({{handler}, button});
+}
+
+auto input_handler::register_mouse_released_handler(const MouseButton button,
+                                                    const std::function<void(input_handler&)>& handler) -> void
+{
+    mouse_released_handlers.push_back({{handler}, button});
+}
+
+auto input_handler::register_key_pressed_handler(const KeyboardKey key,
+                                                 const std::function<void(input_handler&)>& handler) -> void
+{
+    key_pressed_handlers.push_back({{handler}, key});
+}
+
+auto input_handler::register_key_released_handler(const KeyboardKey key,
+                                                  const std::function<void(input_handler&)>& handler) -> void
+{
+    key_released_handlers.push_back({{handler}, key});
+}
+
+auto input_handler::handle_input() -> void
+{
+    if (disable) {
+        return;
+    }
+
+    for (const auto& [handler] : generic_handlers) {
+        handler(*this);
+    }
+
+    for (const mouse_handler& handler : mouse_pressed_handlers) {
+        if (IsMouseButtonPressed(handler.button)) {
+            handler.handler(*this);
+        }
+    }
+
+    for (const mouse_handler& handler : mouse_released_handlers) {
+        if (IsMouseButtonReleased(handler.button)) {
+            handler.handler(*this);
+        }
+    }
+
+    for (const keyboard_handler& handler : key_pressed_handlers) {
+        if (IsKeyPressed(handler.key)) {
+            handler.handler(*this);
+        }
+    }
+
+    for (const keyboard_handler& handler : key_released_handlers) {
+        if (IsKeyReleased(handler.key)) {
+            handler.handler(*this);
+        }
+    }
+}

src/main.cpp

@@ -1,130 +1,176 @@
 #include <chrono>
 #include <mutex>
 #include <raylib.h>
-#include <raymath.h>
 
 #include "config.hpp"
-#include "gui.hpp"
-#include "input.hpp"
-#include "physics.hpp"
+#include "input_handler.hpp"
+#include "mass_spring_system.hpp"
+#include "threaded_physics.hpp"
 #include "renderer.hpp"
-#include "state.hpp"
+#include "state_manager.hpp"
+#include "user_interface.hpp"
 
 #ifdef TRACY
-#include "tracy.hpp"
 #include <tracy/Tracy.hpp>
 #endif
 
+// TODO: Add some popups (my split between input.cpp/gui.cpp makes this ugly)
+//       - Clear graph: Notify that this will clear the visited states and move
+//         history
+//       - Reset state: Notify that this will reset the move count
+
+// TODO: Reduce memory usage
+//       - The memory model of the puzzle board is terrible (bitboards?)
+
+// TODO: Improve solver
+//       - Move discovery is terrible
+//         - Instead of trying each direction for each block, determine the
+//           possible moves more efficiently (requires a different memory model)
+//       - Implement state discovery/enumeration
+//         - Find all possible initial board states (single one for each
+//           possible statespace). Currently wer're just finding all states
+//           given the initial state
+//         - Would allow to generate random puzzles with a certain move count
+
+// TODO: Move selection accordingly when undoing moves (need to diff two states
+//       and get the moved blocks)
+
 // TODO: Click states in the graph to display them in the board
 
 // NOTE: Tracy uses a huge amount of memory. For longer testing disable Tracy.
 
-auto main(int argc, char *argv[]) -> int {
-  std::string preset_file;
-  if (argc != 2) {
-    preset_file = "default.puzzle";
-  } else {
-    preset_file = argv[1];
-  }
+// For profiling explore_state_space
+auto main2(int argc, char* argv[]) -> int
+{
+    const puzzle p = puzzle(
+        "S:[4x5] G:[1,3] M:[F] B:[{_ 2X2 _ _} {1x1 _ _ 1x1} {1x2 2x1 _ 1x2} {_ 2x1 _ _} {1x1 2x1 _ 1x1}]");
 
-  // RayLib window setup
-  SetTraceLogLevel(LOG_ERROR);
-  SetConfigFlags(FLAG_VSYNC_HINT);
-  SetConfigFlags(FLAG_MSAA_4X_HINT);
-  SetConfigFlags(FLAG_WINDOW_RESIZABLE);
-  SetConfigFlags(FLAG_WINDOW_ALWAYS_RUN);
-  InitWindow(INITIAL_WIDTH * 2, INITIAL_HEIGHT + MENU_HEIGHT, "MassSprings");
-
-  // Game setup
-  ThreadedPhysics physics;
-  StateManager state(physics, preset_file);
-  OrbitCamera3D camera;
-  InputHandler input(state, camera);
-  Gui gui(input, state, camera);
-  Renderer renderer(camera, state, input, gui);
-
-  std::chrono::time_point last = std::chrono::high_resolution_clock::now();
-  std::chrono::duration<double> fps_accumulator(0);
-  unsigned int loop_iterations = 0;
-
-  unsigned int fps = 0;
-  unsigned int ups = 0;        // Read from physics
-  std::vector<Vector3> masses; // Read from physics
-
-  // Game loop
-  while (!WindowShouldClose()) {
-#ifdef TRACY
-    FrameMarkStart("MainThread");
-#endif
-
-    // Time tracking
-    std::chrono::time_point now = std::chrono::high_resolution_clock::now();
-    std::chrono::duration<double> deltatime = now - last;
-    fps_accumulator += deltatime;
-    last = now;
-
-    // Input update
-    input.HandleInput();
-    state.UpdateGraph(); // Add state added after user input
-
-    // Read positions from physics thread
-#ifdef TRACY
-    FrameMarkStart("MainThreadConsumeLock");
-#endif
-    {
-#ifdef TRACY
-      std::unique_lock<LockableBase(std::mutex)> lock(physics.state.data_mtx);
-#else
-      std::unique_lock<std::mutex> lock(physics.state.data_mtx);
-#endif
-
-      ups = physics.state.ups;
-
-      // Only copy data if any has been produced
-      if (physics.state.data_ready) {
-        masses = physics.state.masses;
-
-        physics.state.data_ready = false;
-        physics.state.data_consumed = true;
-
-        lock.unlock();
-        // Notify the physics thread that data has been consumed
-        physics.state.data_consumed_cnd.notify_all();
-      }
-    }
-#ifdef TRACY
-    FrameMarkEnd("MainThreadConsumeLock");
-#endif
-
-    // Update the camera after the physics, so target lock is smooth
-    std::size_t current_index = state.CurrentMassIndex();
-    if (masses.size() > current_index) {
-      const Mass &current_mass = masses.at(current_index);
-      camera.Update(current_mass.position, input.camera_lock);
+    for (int i = 0; i < 50; ++i) {
+        auto space = p.explore_state_space();
     }
 
-    // Rendering
-    renderer.UpdateTextureSizes();
-    renderer.DrawMassSprings(masses);
-    renderer.DrawKlotski();
-    renderer.DrawMenu(masses);
-    renderer.DrawTextures(fps, ups);
-
-    if (fps_accumulator.count() > 1.0) {
-      // Update each second
-      fps = loop_iterations;
-      loop_iterations = 0;
-      fps_accumulator = std::chrono::duration<double>(0);
-    }
-    ++loop_iterations;
-
-#ifdef TRACY
-    FrameMark;
-    FrameMarkEnd("MainThread");
-#endif
-  }
-
-  CloseWindow();
-
-  return 0;
+    return 0;
 }
+
+auto main(int argc, char* argv[]) -> int
+{
+    std::string preset_file;
+    if (argc != 2) {
+        preset_file = "default.puzzle";
+    } else {
+        preset_file = argv[1];
+    }
+
+    #ifdef BACKWARD
+    infoln("Backward stack-traces enabled.");
+    #else
+    infoln("Backward stack-traces disabled.");
+    #endif
+
+    #ifdef TRACY
+    infoln("Tracy adapter enabled.");
+    #else
+    infoln("Tracy adapter disabled.");
+    #endif
+
+    // RayLib window setup
+    SetTraceLogLevel(LOG_ERROR);
+    SetConfigFlags(FLAG_VSYNC_HINT);
+    SetConfigFlags(FLAG_MSAA_4X_HINT);
+    SetConfigFlags(FLAG_WINDOW_RESIZABLE);
+    SetConfigFlags(FLAG_WINDOW_ALWAYS_RUN);
+    InitWindow(INITIAL_WIDTH * 2, INITIAL_HEIGHT + MENU_HEIGHT, "MassSprings");
+
+    // Game setup
+    threaded_physics physics;
+    state_manager state(physics, preset_file);
+    orbit_camera camera;
+    input_handler input(state, camera);
+    user_interface gui(input, state, camera);
+    renderer renderer(camera, state, input, gui);
+
+    std::chrono::time_point last = std::chrono::high_resolution_clock::now();
+    std::chrono::duration<double> fps_accumulator(0);
+    int loop_iterations = 0;
+
+    int fps = 0;
+    int ups = 0;                 // Read from physics
+    Vector3 mass_center;         // Read from physics
+    std::vector<Vector3> masses; // Read from physics
+    size_t mass_count = 0;
+    size_t spring_count = 0;
+
+    // Game loop
+    while (!WindowShouldClose()) {
+        #ifdef TRACY
+        FrameMarkStart("MainThread");
+        #endif
+
+        // Time tracking
+        std::chrono::time_point now = std::chrono::high_resolution_clock::now();
+        std::chrono::duration<double> delta_time = now - last;
+        fps_accumulator += delta_time;
+        last = now;
+
+        // Input update
+        input.handle_input();
+
+        // Read positions from physics thread
+        #ifdef TRACY
+        FrameMarkStart("MainThreadConsumeLock");
+        #endif
+        {
+            #ifdef TRACY
+            std::unique_lock<LockableBase(std::mutex)> lock(physics.state.data_mtx);
+            #else
+            std::unique_lock<std::mutex> lock(physics.state.data_mtx);
+            #endif
+
+            ups = physics.state.ups;
+            mass_center = physics.state.mass_center;
+            mass_count = physics.state.mass_count;
+            spring_count = physics.state.spring_count;
+
+            // Only copy data if any has been produced
+            if (physics.state.data_ready) {
+                masses = physics.state.masses;
+
+                physics.state.data_ready = false;
+                physics.state.data_consumed = true;
+
+                lock.unlock();
+                // Notify the physics thread that data has been consumed
+                physics.state.data_consumed_cnd.notify_all();
+            }
+        }
+        #ifdef TRACY
+        FrameMarkEnd("MainThreadConsumeLock");
+        #endif
+
+        // Update the camera after the physics, so target lock is smooth
+        size_t current_index = state.get_current_index();
+        if (masses.size() > current_index) {
+            const mass_spring_system::mass& current_mass = mass_spring_system::mass(masses.at(current_index));
+            camera.update(current_mass.position, mass_center, input.camera_lock, input.camera_mass_center_lock);
+        }
+
+        // Rendering
+        renderer.render(masses, fps, ups, mass_count, spring_count);
+
+        if (fps_accumulator.count() > 1.0) {
+            // Update each second
+            fps = loop_iterations;
+            loop_iterations = 0;
+            fps_accumulator = std::chrono::duration<double>(0);
+        }
+        ++loop_iterations;
+
+        #ifdef TRACY
+        FrameMark; FrameMarkEnd("MainThread");
+        #endif
+    }
+
+    CloseWindow();
+
+    return 0;
+}

src/mass_spring_system.cpp

@@ -0,0 +1,231 @@
+#include "mass_spring_system.hpp"
+#include "config.hpp"
+
+#include <cfloat>
+
+#ifdef TRACY
+#include <tracy/Tracy.hpp>
+#endif
+
+auto mass_spring_system::mass::clear_force() -> void
+{
+    force = Vector3Zero();
+}
+
+auto mass_spring_system::mass::calculate_velocity(const float delta_time) -> void
+{
+    const Vector3 acceleration = Vector3Scale(force, 1.0 / MASS);
+    const Vector3 temp = Vector3Scale(acceleration, delta_time);
+    velocity = Vector3Add(velocity, temp);
+}
+
+auto mass_spring_system::mass::calculate_position(const float delta_time) -> void
+{
+    previous_position = position;
+
+    const Vector3 temp = Vector3Scale(velocity, delta_time);
+    position = Vector3Add(position, temp);
+}
+
+auto mass_spring_system::mass::verlet_update(const float delta_time) -> void
+{
+    const Vector3 acceleration = Vector3Scale(force, 1.0 / MASS);
+    const Vector3 temp_position = position;
+
+    Vector3 displacement = Vector3Subtract(position, previous_position);
+    const Vector3 accel_term = Vector3Scale(acceleration, delta_time * delta_time);
+
+    // Minimal dampening
+    displacement = Vector3Scale(displacement, 1.0 - VERLET_DAMPENING);
+
+    position = Vector3Add(Vector3Add(position, displacement), accel_term);
+    previous_position = temp_position;
+}
+
+auto mass_spring_system::spring::calculate_spring_force(mass& _a, mass& _b) -> void
+{
+    // TODO: Use a bungee force here instead of springs, since we already have global repulsion?
+    const Vector3 delta_position = Vector3Subtract(_a.position, _b.position);
+    const float current_length = Vector3Length(delta_position);
+    const Vector3 delta_velocity = Vector3Subtract(_a.velocity, _b.velocity);
+
+    const float hooke = SPRING_CONSTANT * (current_length - REST_LENGTH);
+    const float dampening = DAMPENING_CONSTANT * Vector3DotProduct(delta_velocity, delta_position) / current_length;
+
+    const Vector3 force_a = Vector3Scale(delta_position, -(hooke + dampening) / current_length);
+    const Vector3 force_b = Vector3Scale(force_a, -1.0);
+
+    _a.force = Vector3Add(_a.force, force_a);
+    _b.force = Vector3Add(_b.force, force_b);
+}
+
+auto mass_spring_system::clear() -> void
+{
+    masses.clear();
+    springs.clear();
+    tree.nodes.clear();
+}
+
+auto mass_spring_system::add_mass() -> void
+{
+    // Adding all positions to (0, 0, 0) breaks the octree
+
+    // Done when adding springs
+    // Vector3 position{
+    //   static_cast<float>(GetRandomValue(-100, 100)), static_cast<float>(GetRandomValue(-100,
+    //   100)), static_cast<float>(GetRandomValue(-100, 100))
+    // };
+    // position = Vector3Scale(Vector3Normalize(position), REST_LENGTH * 2.0);
+
+    masses.emplace_back(Vector3Zero());
+}
+
+auto mass_spring_system::add_spring(size_t a, size_t b) -> void
+{
+    // Update masses to be located along a random walk when adding the springs
+    const mass& mass_a = masses.at(a);
+    mass& mass_b = masses.at(b);
+
+    Vector3 offset{
+        static_cast<float>(GetRandomValue(-100, 100)), static_cast<float>(GetRandomValue(-100, 100)),
+        static_cast<float>(GetRandomValue(-100, 100))
+    };
+    offset = Vector3Normalize(offset) * REST_LENGTH;
+
+    // If the offset moves the mass closer to the current center of mass, flip it
+    if (!tree.nodes.empty()) {
+        const Vector3 mass_center_direction = Vector3Subtract(mass_a.position, tree.nodes.at(0).mass_center);
+        const float mass_center_distance = Vector3Length(mass_center_direction);
+
+        if (mass_center_distance > 0 && Vector3DotProduct(offset, mass_center_direction) < 0.0f) {
+            offset = Vector3Negate(offset);
+        }
+    }
+
+    mass_b.position = mass_a.position + offset;
+    mass_b.previous_position = mass_b.position;
+
+    // infoln("Adding spring: ({}, {}, {})->({}, {}, {})", mass_a.position.x, mass_a.position.y,
+    // mass_a.position.z,
+    //        mass_b.position.x, mass_b.position.y, mass_b.position.z);
+
+    springs.emplace_back(a, b);
+}
+
+auto mass_spring_system::clear_forces() -> void
+{
+    #ifdef TRACY
+    ZoneScoped;
+    #endif
+
+    for (auto& m : masses) {
+        m.clear_force();
+    }
+}
+
+auto mass_spring_system::calculate_spring_forces() -> void
+{
+    #ifdef TRACY
+    ZoneScoped;
+    #endif
+
+    for (const auto s : springs) {
+        mass& a = masses.at(s.a);
+        mass& b = masses.at(s.b);
+        spring::calculate_spring_force(a, b);
+    }
+}
+
+#ifdef THREADPOOL
+auto mass_spring_system::set_thread_name(size_t idx) -> void
+{
+    BS::this_thread::set_os_thread_name(std::format("bh-worker-{}", idx));
+}
+#endif
+
+auto mass_spring_system::build_octree() -> void
+{
+    #ifdef TRACY
+    ZoneScoped;
+    #endif
+
+    tree.nodes.clear();
+    tree.nodes.reserve(masses.size() * 2);
+
+    // Compute bounding box around all masses
+    Vector3 min{FLT_MAX, FLT_MAX, FLT_MAX};
+    Vector3 max{-FLT_MAX, -FLT_MAX, -FLT_MAX};
+    for (const auto& m : masses) {
+        min.x = std::min(min.x, m.position.x);
+        max.x = std::max(max.x, m.position.x);
+        min.y = std::min(min.y, m.position.y);
+        max.y = std::max(max.y, m.position.y);
+        min.z = std::min(min.z, m.position.z);
+        max.z = std::max(max.z, m.position.z);
+    }
+
+    // Pad the bounding box
+    constexpr float pad = 1.0;
+    min = Vector3Subtract(min, Vector3Scale(Vector3One(), pad));
+    max = Vector3Add(max, Vector3Scale(Vector3One(), pad));
+
+    // Make it cubic (so subdivisions are balanced)
+    const float max_extent = std::max({max.x - min.x, max.y - min.y, max.z - min.z});
+    max = Vector3Add(min, Vector3Scale(Vector3One(), max_extent));
+
+    // Root node spans the entire area
+    const int root = tree.create_empty_leaf(min, max);
+
+    for (size_t i = 0; i < masses.size(); ++i) {
+        tree.insert(root, static_cast<int>(i), masses[i].position, MASS, 0);
+    }
+}
+
+auto mass_spring_system::calculate_repulsion_forces() -> void
+{
+    #ifdef TRACY
+    ZoneScoped;
+    #endif
+
+    build_octree();
+
+    auto solve_octree = [&](const int i)
+    {
+        const Vector3 force = tree.calculate_force(0, masses[i].position);
+        masses[i].force = Vector3Add(masses[i].force, force);
+    };
+
+    // Calculate forces using Barnes-Hut
+    #ifdef THREADPOOL
+    const BS::multi_future<void> loop_future = threads.submit_loop(0, masses.size(), solve_octree, 256);
+    loop_future.wait();
+    #else
+    for (size_t i = 0; i < masses.size(); ++i) {
+        solve_octree(i);
+    }
+    #endif
+}
+
+auto mass_spring_system::verlet_update(const float delta_time) -> void
+{
+    #ifdef TRACY
+    ZoneScoped;
+    #endif
+
+    for (auto& m : masses) {
+        m.verlet_update(delta_time);
+    }
+}
+
+auto mass_spring_system::center_masses() -> void
+{
+    Vector3 mean = Vector3Zero();
+    for (const auto& m : masses) {
+        mean += m.position;
+    }
+    mean /= static_cast<float>(masses.size());
+
+    for (auto& m : masses) {
+        m.position -= mean;
+    }
+}

src/octree.cpp

@@ -1,168 +1,193 @@
 #include "octree.hpp"
 #include "config.hpp"
+#include "util.hpp"
 
 #include <raymath.h>
 
 #ifdef TRACY
-#include "tracy.hpp"
 #include <tracy/Tracy.hpp>
 #endif
 
-auto OctreeNode::ChildCount() const -> int {
-  int child_count = 0;
-  for (int child : children) {
-    if (child != -1) {
-      ++child_count;
+auto octree::node::child_count() const -> int
+{
+    int child_count = 0;
+    for (const int child : children) {
+        if (child != -1) {
+            ++child_count;
+        }
     }
-  }
-  return child_count;
+    return child_count;
 }
 
-auto Octree::CreateNode(const Vector3 &box_min, const Vector3 &box_max) -> int {
-  OctreeNode node;
-  node.box_min = box_min;
-  node.box_max = box_max;
-  nodes.push_back(node);
+auto octree::create_empty_leaf(const Vector3& box_min, const Vector3& box_max) -> int
+{
+    node n;
+    n.box_min = box_min;
+    n.box_max = box_max;
+    nodes.emplace_back(n);
 
-  return nodes.size() - 1;
+    return static_cast<int>(nodes.size() - 1);
 }
 
-auto Octree::GetOctant(int node_idx, const Vector3 &pos) -> int {
-  OctreeNode &node = nodes[node_idx];
-  Vector3 center = Vector3((node.box_min.x + node.box_max.x) / 2.0,
-                           (node.box_min.y + node.box_max.y) / 2.0,
-                           (node.box_min.z + node.box_max.z) / 2.0);
+auto octree::get_octant(const int node_idx, const Vector3& pos) const -> int
+{
+    const node& n = nodes[node_idx];
+    auto [cx, cy, cz] = Vector3((n.box_min.x + n.box_max.x) / 2.0f, (n.box_min.y + n.box_max.y) / 2.0f,
+                                (n.box_min.z + n.box_max.z) / 2.0f);
 
-  // The octant is encoded as a 3-bit integer "zyx". The node area is split
-  // along all 3 axes, if a position is right of an axis, this bit is set to 1.
-  // If a position is right of the x-axis and y-axis and left of the z-axis, the
-  // encoded octant is "011".
-  int octant = 0;
-  if (pos.x >= center.x) {
-    octant |= 1;
-  }
-  if (pos.y >= center.y) {
-    octant |= 2;
-  }
-  if (pos.z >= center.z) {
-    octant |= 4;
-  }
+    // The octant is encoded as a 3-bit integer "zyx". The node area is split
+    // along all 3 axes, if a position is right of an axis, this bit is set to 1.
+    // If a position is right of the x-axis and y-axis and left of the z-axis, the
+    // encoded octant is "011".
+    int octant = 0;
+    if (pos.x >= cx) {
+        octant |= 1;
+    }
+    if (pos.y >= cy) {
+        octant |= 2;
+    }
+    if (pos.z >= cz) {
+        octant |= 4;
+    }
 
-  return octant;
+    return octant;
 }
 
-auto Octree::GetChildBounds(int node_idx, int octant)
-    -> std::pair<Vector3, Vector3> {
-  OctreeNode &node = nodes[node_idx];
-  Vector3 center = Vector3((node.box_min.x + node.box_max.x) / 2.0,
-                           (node.box_min.y + node.box_max.y) / 2.0,
-                           (node.box_min.z + node.box_max.z) / 2.0);
+auto octree::get_child_bounds(const int node_idx, const int octant) const -> std::pair<Vector3, Vector3>
+{
+    const node& n = nodes[node_idx];
+    auto [cx, cy, cz] = Vector3((n.box_min.x + n.box_max.x) / 2.0f, (n.box_min.y + n.box_max.y) / 2.0f,
+                                (n.box_min.z + n.box_max.z) / 2.0f);
 
-  Vector3 min = Vector3Zero();
-  Vector3 max = Vector3Zero();
+    Vector3 min = Vector3Zero();
+    Vector3 max = Vector3Zero();
 
-  // If (octant & 1), the octant is to the right of the node region's x-axis
-  // (see GetOctant). This means the left bound is the x-axis and the right
-  // bound the node's region max.
-  min.x = (octant & 1) ? center.x : node.box_min.x;
-  max.x = (octant & 1) ? node.box_max.x : center.x;
-  min.y = (octant & 2) ? center.y : node.box_min.y;
-  max.y = (octant & 2) ? node.box_max.y : center.y;
-  min.z = (octant & 4) ? center.z : node.box_min.z;
-  max.z = (octant & 4) ? node.box_max.z : center.z;
+    // If (octant & 1), the octant is to the right of the node region's x-axis
+    // (see GetOctant). This means the left bound is the x-axis and the right
+    // bound the node's region max.
+    min.x = octant & 1 ? cx : n.box_min.x;
+    max.x = octant & 1 ? n.box_max.x : cx;
+    min.y = octant & 2 ? cy : n.box_min.y;
+    max.y = octant & 2 ? n.box_max.y : cy;
+    min.z = octant & 4 ? cz : n.box_min.z;
+    max.z = octant & 4 ? n.box_max.z : cz;
 
-  return std::make_pair(min, max);
+    return std::make_pair(min, max);
 }
 
-auto Octree::Insert(int node_idx, int mass_id, const Vector3 &pos, float mass)
-    -> void {
-  // NOTE: Do not store a nodes[node_idx] reference beforehand as the nodes
-  //       vector might reallocate during this function
+auto octree::insert(const int node_idx, const int mass_id, const Vector3& pos, const float mass,
+                    const int depth) -> void
+{
+    // infoln("Inserting position ({}, {}, {}) into octree at node {} (depth {})", pos.x, pos.y,
+    // pos.z, node_idx, depth);
+    if (depth > MAX_DEPTH) {
+        throw std::runtime_error(std::format("MAX_DEPTH! node={} box_min=({},{},{}) box_max=({},{},{}) pos=({},{},{})",
+                                             node_idx, nodes[node_idx].box_min.x, nodes[node_idx].box_min.y,
+                                             nodes[node_idx].box_min.z, nodes[node_idx].box_max.x,
+                                             nodes[node_idx].box_max.y, nodes[node_idx].box_max.z, pos.x, pos.y,
+                                             pos.z));
+    }
+
+    // NOTE: Do not store a nodes[node_idx] reference as the nodes vector might reallocate during
+    // this function
 
-  if (nodes[node_idx].leaf && nodes[node_idx].mass_id == -1) {
     // We can place the particle in the empty leaf
-    nodes[node_idx].mass_id = mass_id;
-    nodes[node_idx].mass_center = pos;
-    nodes[node_idx].mass_total = mass;
-    return;
-  }
+    if (nodes[node_idx].leaf && nodes[node_idx].mass_id == -1) {
+        nodes[node_idx].mass_id = mass_id;
+        nodes[node_idx].mass_center = pos;
+        nodes[node_idx].mass_total = mass;
+        return;
+    }
 
-  if (nodes[node_idx].leaf) {
     // The leaf is occupied, we need to subdivide
-    int existing_id = nodes[node_idx].mass_id;
-    Vector3 existing_pos = nodes[node_idx].mass_center;
-    float existing_mass = nodes[node_idx].mass_total;
-    nodes[node_idx].mass_id = -1;
-    nodes[node_idx].leaf = false;
-    nodes[node_idx].mass_total = 0.0;
+    if (nodes[node_idx].leaf) {
+        const int existing_id = nodes[node_idx].mass_id;
+        const Vector3 existing_pos = nodes[node_idx].mass_center;
+        const float existing_mass = nodes[node_idx].mass_total;
 
-    // Re-insert the existing mass into a new empty leaf (see above)
-    int oct = GetOctant(node_idx, existing_pos);
+        // If positions are identical we jitter the particles
+        const Vector3 diff = Vector3Subtract(pos, existing_pos);
+        if (diff == Vector3Zero()) {
+            // warnln("Trying to insert an identical partical into octree (jittering position)");
+
+            Vector3 jittered = pos;
+            jittered.x += 0.001;
+            jittered.y += 0.001;
+            insert(node_idx, mass_id, jittered, mass, depth);
+            return;
+
+            // Could also merge them, but that leads to the octree having less leafs than we have
+            // masses nodes[node_idx].mass_total += mass; return;
+        }
+
+        // Convert the leaf to an internal node
+        nodes[node_idx].mass_id = -1;
+        nodes[node_idx].leaf = false;
+        nodes[node_idx].mass_total = 0.0;
+        nodes[node_idx].mass_center = Vector3Zero();
+
+        // Re-insert the existing mass into a new empty leaf (see above)
+        const int oct = get_octant(node_idx, existing_pos);
+        if (nodes[node_idx].children[oct] == -1) {
+            const auto& [min, max] = get_child_bounds(node_idx, oct);
+            const int child_idx = create_empty_leaf(min, max);
+            nodes[node_idx].children[oct] = child_idx;
+        }
+        insert(nodes[node_idx].children[oct], existing_id, existing_pos, existing_mass, depth + 1);
+    }
+
+    // Insert the new mass
+    const int oct = get_octant(node_idx, pos);
     if (nodes[node_idx].children[oct] == -1) {
-      auto [min, max] = GetChildBounds(node_idx, oct);
-      nodes[node_idx].children[oct] = CreateNode(min, max);
+        const auto& [min, max] = get_child_bounds(node_idx, oct);
+        const int child_idx = create_empty_leaf(min, max);
+        nodes[node_idx].children[oct] = child_idx;
     }
-    Insert(nodes[node_idx].children[oct], existing_id, existing_pos,
-           existing_mass);
-  }
+    insert(nodes[node_idx].children[oct], mass_id, pos, mass, depth + 1);
 
-  // Insert the new mass
-  int oct = GetOctant(node_idx, pos);
-  if (nodes[node_idx].children[oct] == -1) {
-    auto [min, max] = GetChildBounds(node_idx, oct);
-    nodes[node_idx].children[oct] = CreateNode(min, max);
-  }
-  Insert(nodes[node_idx].children[oct], mass_id, pos, mass);
-
-  // Update the center of mass
-  float new_mass = nodes[node_idx].mass_total + mass;
-  nodes[node_idx].mass_center.x =
-      (nodes[node_idx].mass_center.x * nodes[node_idx].mass_total + pos.x) /
-      new_mass;
-  nodes[node_idx].mass_center.y =
-      (nodes[node_idx].mass_center.y * nodes[node_idx].mass_total + pos.y) /
-      new_mass;
-  nodes[node_idx].mass_center.z =
-      (nodes[node_idx].mass_center.z * nodes[node_idx].mass_total + pos.z) /
-      new_mass;
-  nodes[node_idx].mass_total = new_mass;
+    // Update the center of mass
+    const float new_mass = nodes[node_idx].mass_total + mass;
+    nodes[node_idx].mass_center.x = (nodes[node_idx].mass_center.x * nodes[node_idx].mass_total + pos.x) / new_mass;
+    nodes[node_idx].mass_center.y = (nodes[node_idx].mass_center.y * nodes[node_idx].mass_total + pos.y) / new_mass;
+    nodes[node_idx].mass_center.z = (nodes[node_idx].mass_center.z * nodes[node_idx].mass_total + pos.z) / new_mass;
+    nodes[node_idx].mass_total = new_mass;
 }
 
-auto Octree::CalculateForce(int node_idx, const Vector3 &pos) const -> Vector3 {
-  if (node_idx < 0) {
-    return Vector3Zero();
-  }
-
-  const OctreeNode &node = nodes[node_idx];
-  if (std::abs(node.mass_total) <= 0.001f) {
-    return Vector3Zero();
-  }
-
-  Vector3 diff = Vector3Subtract(pos, node.mass_center);
-  float dist_sq = diff.x * diff.x + diff.y * diff.y + diff.z * diff.z;
-
-  // Softening
-  dist_sq += SOFTENING;
-
-  float size = node.box_max.x - node.box_min.x;
-
-  // Barnes-Hut
-  if (node.leaf || (size * size / dist_sq) < (THETA * THETA)) {
-    float dist = std::sqrt(dist_sq);
-    float force_mag = BH_FORCE * node.mass_total / dist_sq;
-
-    return Vector3Scale(diff, force_mag / dist);
-  }
-
-  // Collect child forces
-  Vector3 force = Vector3Zero();
-  for (int i = 0; i < 8; ++i) {
-    if (node.children[i] >= 0) {
-      Vector3 child_force = CalculateForce(node.children[i], pos);
-
-      force = Vector3Add(force, child_force);
+auto octree::calculate_force(const int node_idx, const Vector3& pos) const -> Vector3
+{
+    if (node_idx < 0) {
+        return Vector3Zero();
     }
-  }
 
-  return force;
-}
+    const node& n = nodes[node_idx];
+    if (std::abs(n.mass_total) <= 0.001f) {
+        return Vector3Zero();
+    }
+
+    const Vector3 diff = Vector3Subtract(pos, n.mass_center);
+    float dist_sq = diff.x * diff.x + diff.y * diff.y + diff.z * diff.z;
+
+    // Softening
+    dist_sq += SOFTENING;
+
+    // Barnes-Hut
+    const float size = n.box_max.x - n.box_min.x;
+    if (n.leaf || size * size / dist_sq < THETA * THETA) {
+        const float dist = std::sqrt(dist_sq);
+        const float force_mag = BH_FORCE * n.mass_total / dist_sq;
+
+        return Vector3Scale(diff, force_mag / dist);
+    }
+
+    // Collect child forces
+    Vector3 force = Vector3Zero();
+    for (const int child : n.children) {
+        if (child >= 0) {
+            const Vector3 child_force = calculate_force(child, pos);
+
+            force = Vector3Add(force, child_force);
+        }
+    }
+
+    return force;
+}

src/orbit_camera.cpp

@@ -0,0 +1,76 @@
+#include "orbit_camera.hpp"
+#include "config.hpp"
+
+#include <raylib.h>
+#include <raymath.h>
+
+#ifdef TRACY
+    #include <tracy/Tracy.hpp>
+#endif
+
+auto orbit_camera::rotate(const Vector2 last_mouse, const Vector2 mouse) -> void
+{
+    const auto [dx, dy] = Vector2Subtract(mouse, last_mouse);
+
+    angle_x -= dx * ROT_SPEED / 200.0f;
+    angle_y += dy * ROT_SPEED / 200.0f;
+
+    angle_y = Clamp(angle_y, -1.5, 1.5); // Prevent flipping
+}
+
+auto orbit_camera::pan(const Vector2 last_mouse, const Vector2 mouse) -> void
+{
+    const auto [dx, dy] = Vector2Subtract(mouse, last_mouse);
+
+    float speed;
+    if (IsKeyDown(KEY_LEFT_SHIFT)) {
+        speed = distance * PAN_SPEED / 1000.0f * PAN_MULTIPLIER;
+    } else {
+        speed = distance * PAN_SPEED / 1000.0f;
+    }
+
+    // The panning needs to happen in camera coordinates, otherwise rotating the
+    // camera breaks it
+    const Vector3 forward = Vector3Normalize(Vector3Subtract(camera.target, camera.position));
+    const Vector3 right = Vector3Normalize(Vector3CrossProduct(forward, camera.up));
+    const Vector3 up = Vector3Normalize(Vector3CrossProduct(right, forward));
+
+    const Vector3 offset =
+        Vector3Add(Vector3Scale(right, -dx * speed), Vector3Scale(up, dy * speed));
+
+    target = Vector3Add(target, offset);
+}
+
+auto orbit_camera::update(const Vector3& current_target, const Vector3& mass_center,
+                          const bool lock, const bool mass_center_lock) -> void
+{
+    if (lock) {
+        if (mass_center_lock) {
+            target = Vector3MoveTowards(target, mass_center,
+                                        CAMERA_SMOOTH_SPEED * GetFrameTime() *
+                                            Vector3Length(Vector3Subtract(target, mass_center)));
+        } else {
+            target = Vector3MoveTowards(target, current_target,
+                                        CAMERA_SMOOTH_SPEED * GetFrameTime() *
+                                            Vector3Length(Vector3Subtract(target, current_target)));
+        }
+    }
+
+    distance = Clamp(distance, MIN_CAMERA_DISTANCE, MAX_CAMERA_DISTANCE);
+    float actual_distance = distance;
+    if (projection == CAMERA_ORTHOGRAPHIC) {
+        actual_distance = MAX_CAMERA_DISTANCE;
+    }
+
+    // Spherical coordinates
+    const float x = cos(angle_y) * sin(angle_x) * actual_distance;
+    const float y = sin(angle_y) * actual_distance;
+    const float z = cos(angle_y) * cos(angle_x) * actual_distance;
+
+    fov = Clamp(fov, MIN_FOV, MAX_FOV);
+
+    camera.position = Vector3Add(target, Vector3(x, y, z));
+    camera.target = target;
+    camera.fovy = fov;
+    camera.projection = projection;
+}

src/physics.cpp

@@ -1,353 +0,0 @@
-#include "physics.hpp"
-#include "config.hpp"
-
-#include <algorithm>
-#include <cfloat>
-#include <chrono>
-#include <cstddef>
-#include <raylib.h>
-#include <raymath.h>
-#include <utility>
-#include <vector>
-
-#ifdef THREADPOOL
-#define BS_THREAD_POOL_NATIVE_EXTENSIONS
-#include <BS_thread_pool.hpp>
-#endif
-
-#ifdef TRACY
-#include "tracy.hpp"
-#include <tracy/Tracy.hpp>
-#endif
-
-auto Mass::ClearForce() -> void { force = Vector3Zero(); }
-
-auto Mass::CalculateVelocity(const float delta_time) -> void {
-  Vector3 acceleration;
-  Vector3 temp;
-
-  acceleration = Vector3Scale(force, 1.0 / MASS);
-  temp = Vector3Scale(acceleration, delta_time);
-  velocity = Vector3Add(velocity, temp);
-}
-
-auto Mass::CalculatePosition(const float delta_time) -> void {
-  previous_position = position;
-
-  Vector3 temp;
-
-  temp = Vector3Scale(velocity, delta_time);
-  position = Vector3Add(position, temp);
-}
-
-auto Mass::VerletUpdate(const float delta_time) -> void {
-  Vector3 acceleration = Vector3Scale(force, 1.0 / MASS);
-  Vector3 temp_position = position;
-
-  Vector3 displacement = Vector3Subtract(position, previous_position);
-  Vector3 accel_term = Vector3Scale(acceleration, delta_time * delta_time);
-
-  // Minimal dampening
-  displacement = Vector3Scale(displacement, 1.0 - VERLET_DAMPENING);
-
-  position = Vector3Add(Vector3Add(position, displacement), accel_term);
-  previous_position = temp_position;
-}
-
-auto Spring::CalculateSpringForce(Mass &_mass_a, Mass &_mass_b) const -> void {
-  Vector3 delta_position = Vector3Subtract(_mass_a.position, _mass_b.position);
-  float current_length = Vector3Length(delta_position);
-  float inv_current_length = 1.0 / current_length;
-  Vector3 delta_velocity = Vector3Subtract(_mass_a.velocity, _mass_b.velocity);
-
-  float hooke = SPRING_CONSTANT * (current_length - REST_LENGTH);
-  float dampening = DAMPENING_CONSTANT *
-                    Vector3DotProduct(delta_velocity, delta_position) *
-                    inv_current_length;
-
-  Vector3 force_a =
-      Vector3Scale(delta_position, -(hooke + dampening) * inv_current_length);
-  Vector3 force_b = Vector3Scale(force_a, -1.0);
-
-  _mass_a.force = Vector3Add(_mass_a.force, force_a);
-  _mass_b.force = Vector3Add(_mass_b.force, force_b);
-}
-
-auto MassSpringSystem::AddMass() -> void { masses.emplace_back(Vector3Zero()); }
-
-auto MassSpringSystem::AddSpring(int a, int b) -> void {
-  Mass &mass_a = masses.at(a);
-  Mass &mass_b = masses.at(b);
-
-  Vector3 position = mass_a.position;
-  Vector3 offset = Vector3(static_cast<float>(GetRandomValue(-100, 100)),
-                           static_cast<float>(GetRandomValue(-100, 100)),
-                           static_cast<float>(GetRandomValue(-100, 100)));
-  offset = Vector3Scale(Vector3Normalize(offset), REST_LENGTH);
-
-  if (mass_b.position == Vector3Zero()) {
-    mass_b.position = Vector3Add(position, offset);
-  }
-
-  springs.emplace_back(a, b);
-}
-
-auto MassSpringSystem::Clear() -> void {
-  masses.clear();
-  springs.clear();
-  octree.nodes.clear();
-}
-
-auto MassSpringSystem::ClearForces() -> void {
-#ifdef TRACY
-  ZoneScoped;
-#endif
-
-  for (auto &mass : masses) {
-    mass.ClearForce();
-  }
-}
-
-auto MassSpringSystem::CalculateSpringForces() -> void {
-#ifdef TRACY
-  ZoneScoped;
-#endif
-
-  for (const auto spring : springs) {
-    Mass &a = masses.at(spring.a);
-    Mass &b = masses.at(spring.b);
-    spring.CalculateSpringForce(a, b);
-  }
-}
-
-#ifdef THREADPOOL
-auto MassSpringSystem::SetThreadName(std::size_t idx) -> void {
-  BS::this_thread::set_os_thread_name(std::format("bh-worker-{}", idx));
-}
-#endif
-
-auto MassSpringSystem::BuildOctree() -> void {
-#ifdef TRACY
-  ZoneScoped;
-#endif
-
-  octree.nodes.clear();
-  octree.nodes.reserve(masses.size() * 2);
-
-  // Compute bounding box around all masses
-  Vector3 min = Vector3(FLT_MAX, FLT_MAX, FLT_MAX);
-  Vector3 max = Vector3(-FLT_MAX, -FLT_MAX, -FLT_MAX);
-  for (const auto &mass : masses) {
-    min.x = std::min(min.x, mass.position.x);
-    max.x = std::max(max.x, mass.position.x);
-    min.y = std::min(min.y, mass.position.y);
-    max.y = std::max(max.y, mass.position.y);
-    min.z = std::min(min.z, mass.position.z);
-    max.z = std::max(max.z, mass.position.z);
-  }
-
-  // Pad the bounding box
-  float pad = 1.0;
-  min = Vector3Subtract(min, Vector3Scale(Vector3One(), pad));
-  max = Vector3Add(max, Vector3Scale(Vector3One(), pad));
-
-  // Make it cubic (so subdivisions are balanced)
-  float max_extent = std::max({max.x - min.x, max.y - min.y, max.z - min.z});
-  max = Vector3Add(min, Vector3Scale(Vector3One(), max_extent));
-
-  // Root node spans the entire area
-  int root = octree.CreateNode(min, max);
-
-  for (std::size_t i = 0; i < masses.size(); ++i) {
-    octree.Insert(root, i, masses[i].position, MASS);
-  }
-}
-
-auto MassSpringSystem::CalculateRepulsionForces() -> void {
-#ifdef TRACY
-  ZoneScoped;
-#endif
-
-  BuildOctree();
-
-  auto solve_octree = [&](int i) {
-    Vector3 force = octree.CalculateForce(0, masses[i].position);
-    masses[i].force = Vector3Add(masses[i].force, force);
-  };
-
-// Calculate forces using Barnes-Hut
-#ifdef THREADPOOL
-  BS::multi_future<void> loop_future =
-      threads.submit_loop(0, masses.size(), solve_octree, 256);
-  loop_future.wait();
-#else
-  for (std::size_t i = 0; i < masses.size(); ++i) {
-    solve_octree(i);
-  }
-#endif
-}
-
-auto MassSpringSystem::VerletUpdate(float delta_time) -> void {
-#ifdef TRACY
-  ZoneScoped;
-#endif
-
-  for (auto &mass : masses) {
-    mass.VerletUpdate(delta_time);
-  }
-}
-
-auto ThreadedPhysics::PhysicsThread(ThreadedPhysics::PhysicsState &state)
-    -> void {
-#ifdef THREADPOOL
-  BS::this_thread::set_os_thread_name("physics");
-#endif
-
-  MassSpringSystem mass_springs;
-
-  const auto visitor = overloads{
-      [&](const struct AddMass &am) { mass_springs.AddMass(); },
-      [&](const struct AddSpring &as) { mass_springs.AddSpring(as.a, as.b); },
-      [&](const struct ClearGraph &cg) { mass_springs.Clear(); },
-  };
-
-  std::chrono::time_point last = std::chrono::high_resolution_clock::now();
-  std::chrono::duration<double> physics_accumulator(0);
-  std::chrono::duration<double> ups_accumulator(0);
-  unsigned int loop_iterations = 0;
-
-  while (state.running.load()) {
-#ifdef TRACY
-    FrameMarkStart("PhysicsThread");
-#endif
-
-    // Time tracking
-    std::chrono::time_point now = std::chrono::high_resolution_clock::now();
-    std::chrono::duration<double> deltatime = now - last;
-    physics_accumulator += deltatime;
-    ups_accumulator += deltatime;
-    last = now;
-
-    // Handle queued commands
-    {
-#ifdef TRACY
-      std::lock_guard<LockableBase(std::mutex)> lock(state.command_mtx);
-#else
-      std::lock_guard<std::mutex> lock(state.command_mtx);
-#endif
-      while (!state.pending_commands.empty()) {
-        Command &cmd = state.pending_commands.front();
-        cmd.visit(visitor);
-        state.pending_commands.pop();
-      }
-    }
-
-    if (mass_springs.masses.empty()) {
-      std::this_thread::sleep_for(std::chrono::milliseconds(1));
-      continue;
-    }
-
-    // Physics update
-    if (physics_accumulator.count() > TIMESTEP) {
-      mass_springs.ClearForces();
-      mass_springs.CalculateSpringForces();
-      mass_springs.CalculateRepulsionForces();
-      mass_springs.VerletUpdate(TIMESTEP * SIM_SPEED);
-
-      ++loop_iterations;
-      physics_accumulator -= std::chrono::duration<double>(TIMESTEP);
-    }
-
-    // Publish the positions for the renderer (copy)
-#ifdef TRACY
-    FrameMarkStart("PhysicsThreadProduceLock");
-#endif
-    {
-#ifdef TRACY
-      std::unique_lock<LockableBase(std::mutex)> lock(state.data_mtx);
-#else
-      std::unique_lock<std::mutex> lock(state.data_mtx);
-#endif
-      state.data_consumed_cnd.wait(
-          lock, [&] { return state.data_consumed || !state.running.load(); });
-      if (!state.running.load()) {
-        // Running turned false while we were waiting for the condition
-        break;
-      }
-
-      if (ups_accumulator.count() > 1.0) {
-        // Update each second
-        state.ups = loop_iterations;
-        loop_iterations = 0;
-        ups_accumulator = std::chrono::duration<double>(0);
-      }
-
-      state.masses.clear();
-      state.masses.reserve(mass_springs.masses.size());
-      for (const auto &mass : mass_springs.masses) {
-        state.masses.emplace_back(mass.position);
-      }
-
-      state.data_ready = true;
-      state.data_consumed = false;
-    }
-    // Notify the rendering thread that new data is available
-    state.data_ready_cnd.notify_all();
-#ifdef TRACY
-    FrameMarkEnd("PhysicsThreadProduceLock");
-
-    FrameMarkEnd("PhysicsThread");
-#endif
-  }
-}
-
-auto ThreadedPhysics::AddMassCmd() -> void {
-  {
-#ifdef TRACY
-    std::lock_guard<LockableBase(std::mutex)> lock(state.command_mtx);
-#else
-    std::lock_guard<std::mutex> lock(state.command_mtx);
-#endif
-    state.pending_commands.push(AddMass{});
-  }
-}
-
-auto ThreadedPhysics::AddSpringCmd(std::size_t a, std::size_t b) -> void {
-  {
-#ifdef TRACY
-    std::lock_guard<LockableBase(std::mutex)> lock(state.command_mtx);
-#else
-    std::lock_guard<std::mutex> lock(state.command_mtx);
-#endif
-    state.pending_commands.push(AddSpring{a, b});
-  }
-}
-
-auto ThreadedPhysics::ClearCmd() -> void {
-  {
-#ifdef TRACY
-    std::lock_guard<LockableBase(std::mutex)> lock(state.command_mtx);
-#else
-    std::lock_guard<std::mutex> lock(state.command_mtx);
-#endif
-    state.pending_commands.push(ClearGraph{});
-  }
-}
-
-auto ThreadedPhysics::AddMassSpringsCmd(
-    std::size_t num_masses,
-    const std::vector<std::pair<std::size_t, std::size_t>> &springs) -> void {
-  {
-#ifdef TRACY
-    std::lock_guard<LockableBase(std::mutex)> lock(state.command_mtx);
-#else
-    std::lock_guard<std::mutex> lock(state.command_mtx);
-#endif
-    for (std::size_t i = 0; i < num_masses; ++i) {
-      state.pending_commands.push(AddMass{});
-    }
-    for (const auto &[from, to] : springs) {
-      state.pending_commands.push(AddSpring{from, to});
-    }
-  }
-}

src/renderer.cpp

@@ -1,244 +1,230 @@
 #include "renderer.hpp"
 #include "config.hpp"
-#include "puzzle.hpp"
 
-#include <algorithm>
 #include <raylib.h>
 #include <raymath.h>
 #include <rlgl.h>
 
 #ifdef TRACY
-#include "tracy.hpp"
-#include <tracy/Tracy.hpp>
+    #include <tracy/Tracy.hpp>
 #endif
 
-#ifdef BATCHING
-#include <cstring>
-#endif
-
-auto Renderer::UpdateTextureSizes() -> void {
-  if (!IsWindowResized()) {
-    return;
-  }
-
-  UnloadRenderTexture(render_target);
-  UnloadRenderTexture(klotski_target);
-  UnloadRenderTexture(menu_target);
-
-  int width = GetScreenWidth() / 2.0;
-  int height = GetScreenHeight() - MENU_HEIGHT;
-
-  render_target = LoadRenderTexture(width, height);
-  klotski_target = LoadRenderTexture(width, height);
-  menu_target = LoadRenderTexture(width * 2, MENU_HEIGHT);
-}
-
-auto Renderer::AllocateGraphInstancing(std::size_t size) -> void {
-  cube_instance = GenMeshCube(VERTEX_SIZE, VERTEX_SIZE, VERTEX_SIZE);
-
-  instancing_shader = LoadShader("shader/instancing_vertex.glsl",
-                                 "shader/instancing_fragment.glsl");
-  instancing_shader.locs[SHADER_LOC_MATRIX_MVP] =
-      GetShaderLocation(instancing_shader, "mvp");
-  instancing_shader.locs[SHADER_LOC_VECTOR_VIEW] =
-      GetShaderLocation(instancing_shader, "viewPos");
-
-  vertex_mat = LoadMaterialDefault();
-  vertex_mat.maps[MATERIAL_MAP_DIFFUSE].color = VERTEX_COLOR;
-  vertex_mat.shader = instancing_shader;
-
-  transforms = (Matrix *)MemAlloc(size * sizeof(Matrix));
-  transforms_size = size;
-}
-
-auto Renderer::ReallocateGraphInstancingIfNecessary(std::size_t size) -> void {
-  if (transforms_size != size) {
-    transforms = (Matrix *)MemRealloc(transforms, size * sizeof(Matrix));
-    transforms_size = size;
-  }
-}
-
-auto Renderer::DrawMassSprings(const std::vector<Vector3> &masses) -> void {
-#ifdef TRACY
-  ZoneScoped;
-#endif
-
-  // Prepare cube instancing
-  {
-#ifdef TRACY
-    ZoneNamedN(prepare_masses, "PrepareMasses", true);
-#endif
-    if (masses.size() < DRAW_VERTICES_LIMIT) {
-      if (transforms == nullptr) {
-        AllocateGraphInstancing(masses.size());
-      }
-      ReallocateGraphInstancingIfNecessary(masses.size());
-
-      int i = 0;
-      for (const Vector3 &mass : masses) {
-        transforms[i] = MatrixTranslate(mass.x, mass.y, mass.z);
-        ++i;
-      }
+auto renderer::update_texture_sizes() -> void
+{
+    if (!IsWindowResized()) {
+        return;
     }
-  }
 
-  BeginTextureMode(render_target);
-  ClearBackground(RAYWHITE);
+    UnloadRenderTexture(render_target);
+    UnloadRenderTexture(klotski_target);
+    UnloadRenderTexture(menu_target);
 
-  BeginMode3D(camera.camera);
+    const int width = GetScreenWidth() / 2;
+    const int height = GetScreenHeight() - MENU_HEIGHT;
 
-  // Draw springs (batched)
-  {
+    render_target = LoadRenderTexture(width, height);
+    klotski_target = LoadRenderTexture(width, height);
+    menu_target = LoadRenderTexture(width * 2, MENU_HEIGHT);
+}
+
+auto renderer::draw_mass_springs(const std::vector<Vector3>& masses) -> void
+{
 #ifdef TRACY
-    ZoneNamedN(draw_springs, "DrawSprings", true);
+    ZoneScoped;
 #endif
+
+    if (masses.size() != state.get_state_count()) {
+        // Because the physics run in a different thread, it might need time to catch up
+        return;
+    }
+
+    // Prepare connection batching
+    {
+#ifdef TRACY
+        ZoneNamedN(prepare_masses, "PrepareConnectionsBatching", true);
+#endif
+
+        connections.clear();
+        connections.reserve(state.get_target_count());
+        if (input.connect_solutions) {
+            for (const size_t& _state : state.get_winning_indices()) {
+                const Vector3& current_mass = masses.at(state.get_current_index());
+                const Vector3& winning_mass = masses.at(_state);
+                connections.emplace_back(current_mass, winning_mass);
+                DrawLine3D(current_mass, winning_mass, Fade(TARGET_BLOCK_COLOR, 0.5));
+            }
+        }
+    }
+
+    // Prepare cube instancing
+    {
+#ifdef TRACY
+        ZoneNamedN(prepare_masses, "PrepareMassInstancing", true);
+#endif
+
+        if (masses.size() < DRAW_VERTICES_LIMIT) {
+            // Don't have to reserve, capacity is already set to DRAW_VERTICES_LIMIT in constructor
+            transforms.clear();
+            colors.clear();
+
+            size_t mass = 0;
+            for (const auto& [x, y, z] : masses) {
+                transforms.emplace_back(MatrixTranslate(x, y, z));
+
+                // Normal vertex
+                Color c = VERTEX_COLOR;
+                if ((input.mark_solutions || input.mark_path) &&
+                    state.get_winning_indices().contains(mass)) {
+                    // Winning vertex
+                    c = VERTEX_TARGET_COLOR;
+                } else if ((input.mark_solutions || input.mark_path) &&
+                           state.get_path_indices().contains(mass)) {
+                    // Path vertex
+                    c = VERTEX_PATH_COLOR;
+                } else if (mass == state.get_starting_index()) {
+                    // Starting vertex
+                    c = VERTEX_START_COLOR;
+                } else if (state.get_visit_counts().at(mass) > 0) {
+                    // Visited vertex
+                    c = VERTEX_VISITED_COLOR;
+                }
+                // Current vertex is drawn as individual cube to increase its size
+
+                colors.emplace_back(c);
+                ++mass;
+            }
+        }
+
+        rlUpdateVertexBuffer(color_vbo_id, colors.data(), colors.size() * sizeof(Color), 0);
+    }
+
+    BeginTextureMode(render_target);
+    ClearBackground(RAYWHITE);
+    BeginMode3D(camera.camera);
+
+    // Draw springs (batched)
+    {
+#ifdef TRACY
+        ZoneNamedN(draw_springs, "DrawSprings", true);
+#endif
+
+        rlBegin(RL_LINES);
+        for (const auto& [from, to] : state.get_links()) {
+            if (masses.size() > from && masses.size() > to) {
+                const auto& [ax, ay, az] = masses.at(from);
+                const auto& [bx, by, bz] = masses.at(to);
+                rlColor4ub(EDGE_COLOR.r, EDGE_COLOR.g, EDGE_COLOR.b, EDGE_COLOR.a);
+                rlVertex3f(ax, ay, az);
+                rlVertex3f(bx, by, bz);
+            }
+        }
+        rlEnd();
+    }
+
+    // Draw masses (instanced)
+    {
+#ifdef TRACY
+        ZoneNamedN(draw_masses, "DrawMasses", true);
+#endif
+
+        if (masses.size() < DRAW_VERTICES_LIMIT) {
+            // NOTE: I don't know if drawing all this inside a shader would make it
+            //       much faster... The amount of data sent to the GPU would be
+            //       reduced (just positions instead of matrices), but is this
+            //       noticable for < 100000 cubes?
+            DrawMeshInstanced(cube_instance, vertex_mat, transforms.data(),
+                              masses.size()); // NOLINT(*-narrowing-conversions)
+        }
+    }
+
+    // Connect current to winning states (batched)
+    const auto [r, g, b, a] = Fade(VERTEX_CURRENT_COLOR, 0.3);
     rlBegin(RL_LINES);
-    for (const auto &[from, to] : state.springs) {
-      if (masses.size() > from && masses.size() > to) {
-        const Vector3 &a = masses.at(from);
-        const Vector3 &b = masses.at(to);
-        rlColor4ub(EDGE_COLOR.r, EDGE_COLOR.g, EDGE_COLOR.b, EDGE_COLOR.a);
-        rlVertex3f(a.x, a.y, a.z);
-        rlVertex3f(b.x, b.y, b.z);
-      }
+    for (const auto& [from, to] : connections) {
+        const auto& [ax, ay, az] = from;
+        const auto& [bx, by, bz] = to;
+        rlColor4ub(r, g, b, a);
+        rlVertex3f(ax, ay, az);
+        rlVertex3f(bx, by, bz);
     }
     rlEnd();
-  }
 
-  // Draw masses (instanced)
-  {
-#ifdef TRACY
-    ZoneNamedN(draw_masses, "DrawMasses", true);
-#endif
-    if (masses.size() < DRAW_VERTICES_LIMIT) {
-      // NOTE: I don't know if drawing all this inside a shader would make it
-      //       much faster... The amount of data sent to the GPU would be
-      //       reduced (just positions instead of matrices), but is this
-      //       noticable for < 100000 cubes?
-      DrawMeshInstanced(cube_instance, vertex_mat, transforms, masses.size());
+    // Mark current state
+    const size_t current_index = state.get_current_index();
+    if (masses.size() > current_index) {
+        const Vector3& current_mass = masses.at(current_index);
+        DrawCube(current_mass, VERTEX_SIZE * 2, VERTEX_SIZE * 2, VERTEX_SIZE * 2,
+                 VERTEX_CURRENT_COLOR);
     }
-  }
 
-  // Mark winning states
-  if (input.mark_solutions || input.connect_solutions) {
-    for (const State &_state : state.winning_states) {
-
-      std::size_t winning_index = state.states.at(_state);
-      if (masses.size() > winning_index) {
-
-        const Vector3 &winning_mass = masses.at(winning_index);
-        if (input.mark_solutions) {
-          DrawCube(winning_mass, 2 * VERTEX_SIZE, 2 * VERTEX_SIZE,
-                   2 * VERTEX_SIZE, TARGET_BLOCK_COLOR);
-        }
-
-        std::size_t current_index = state.CurrentMassIndex();
-        if (input.connect_solutions && masses.size() > current_index) {
-          const Vector3 &current_mass = masses.at(current_index);
-          DrawLine3D(winning_mass, current_mass, ORANGE);
-        }
-      }
-    }
-  }
-
-  // Mark visited states
-  for (const auto &[_state, visits] : state.visited_states) {
-    std::size_t visited_index = state.states.at(_state);
-
-    if (masses.size() > visited_index) {
-      const Vector3 &visited_mass = masses.at(visited_index);
-      DrawCube(visited_mass, VERTEX_SIZE * 1.5, VERTEX_SIZE * 1.5,
-               VERTEX_SIZE * 1.5, PURPLE);
-    }
-  }
-
-  // Mark winning path
-  if (input.mark_path) {
-    for (const std::size_t &_state : state.winning_path) {
-      if (masses.size() > _state) {
-        const Vector3 &path_mass = masses.at(_state);
-        DrawCube(path_mass, VERTEX_SIZE * 1.75, VERTEX_SIZE * 1.75,
-                 VERTEX_SIZE * 1.75, YELLOW);
-      }
-    }
-  }
-
-  // Mark starting state
-  std::size_t starting_index = state.states.at(state.starting_state);
-  if (masses.size() > starting_index) {
-    const Vector3 &starting_mass = masses.at(starting_index);
-    DrawCube(starting_mass, VERTEX_SIZE * 2, VERTEX_SIZE * 2, VERTEX_SIZE * 2,
-             ORANGE);
-  }
-
-  // Mark current state
-  std::size_t current_index = state.states.at(state.current_state);
-  if (masses.size() > current_index) {
-    const Vector3 &current_mass = masses.at(current_index);
-    DrawCube(current_mass, VERTEX_SIZE * 2, VERTEX_SIZE * 2, VERTEX_SIZE * 2,
-             BLUE);
-  }
-
-  EndMode3D();
-  EndTextureMode();
+    EndMode3D();
+    EndTextureMode();
 }
 
-auto Renderer::DrawKlotski() -> void {
+auto renderer::draw_klotski() const -> void
+{
 #ifdef TRACY
-  ZoneScoped;
+    ZoneScoped;
 #endif
 
-  BeginTextureMode(klotski_target);
-  ClearBackground(RAYWHITE);
+    BeginTextureMode(klotski_target);
+    ClearBackground(RAYWHITE);
 
-  gui.DrawPuzzleBoard();
+    gui.draw_puzzle_board();
 
-  EndTextureMode();
+    EndTextureMode();
 }
 
-auto Renderer::DrawMenu(const std::vector<Vector3> &masses) -> void {
+auto renderer::draw_menu() const -> void
+{
 #ifdef TRACY
-  ZoneScoped;
+    ZoneScoped;
 #endif
 
-  BeginTextureMode(menu_target);
-  ClearBackground(RAYWHITE);
+    BeginTextureMode(menu_target);
+    ClearBackground(RAYWHITE);
 
-  gui.DrawMainMenu();
+    gui.draw_main_menu();
 
-  EndTextureMode();
+    EndTextureMode();
 }
 
-auto Renderer::DrawTextures(int fps, int ups) -> void {
-  BeginDrawing();
+auto renderer::draw_textures(const int fps, const int ups, const size_t mass_count,
+                             const size_t spring_count) const -> void
+{
+    BeginDrawing();
 
-  DrawTextureRec(menu_target.texture,
-                 Rectangle(0, 0, menu_target.texture.width,
-                           -1 * menu_target.texture.height),
-                 Vector2(0, 0), WHITE);
-  DrawTextureRec(klotski_target.texture,
-                 Rectangle(0, 0, klotski_target.texture.width,
-                           -1 * klotski_target.texture.height),
-                 Vector2(0, MENU_HEIGHT), WHITE);
-  DrawTextureRec(render_target.texture,
-                 Rectangle(0, 0, render_target.texture.width,
-                           -1 * render_target.texture.height),
-                 Vector2(GetScreenWidth() / 2.0, MENU_HEIGHT), WHITE);
+    DrawTextureRec(menu_target.texture,
+                   Rectangle(0, 0, menu_target.texture.width, -menu_target.texture.height),
+                   Vector2(0, 0), WHITE);
+    DrawTextureRec(klotski_target.texture,
+                   Rectangle(0, 0, klotski_target.texture.width, -klotski_target.texture.height),
+                   Vector2(0, MENU_HEIGHT), WHITE);
+    DrawTextureRec(render_target.texture,
+                   Rectangle(0, 0, render_target.texture.width, -render_target.texture.height),
+                   Vector2(GetScreenWidth() / 2.0f, MENU_HEIGHT), WHITE);
 
-  // Draw borders
-  DrawRectangleLinesEx(Rectangle(0, 0, GetScreenWidth(), MENU_HEIGHT), 1.0,
-                       BLACK);
-  DrawRectangleLinesEx(Rectangle(0, MENU_HEIGHT, GetScreenWidth() / 2.0,
-                                 GetScreenHeight() - MENU_HEIGHT),
-                       1.0, BLACK);
-  DrawRectangleLinesEx(Rectangle(GetScreenWidth() / 2.0, MENU_HEIGHT,
-                                 GetScreenWidth() / 2.0,
-                                 GetScreenHeight() - MENU_HEIGHT),
-                       1.0, BLACK);
+    // Draw borders
+    DrawRectangleLinesEx(Rectangle(0, 0, GetScreenWidth(), MENU_HEIGHT), 1.0f, BLACK);
+    DrawRectangleLinesEx(
+        Rectangle(0, MENU_HEIGHT, GetScreenWidth() / 2.0f, GetScreenHeight() - MENU_HEIGHT), 1.0f,
+        BLACK);
+    DrawRectangleLinesEx(Rectangle(GetScreenWidth() / 2.0f, MENU_HEIGHT, GetScreenWidth() / 2.0f,
+                                   GetScreenHeight() - MENU_HEIGHT),
+                         1.0f, BLACK);
 
-  gui.DrawGraphOverlay(fps, ups);
-  gui.DrawSavePresetPopup();
-  gui.Update();
+    gui.draw(fps, ups, mass_count, spring_count);
 
-  EndDrawing();
+    EndDrawing();
+}
+
+auto renderer::render(const std::vector<Vector3>& masses, const int fps, const int ups,
+                      const size_t mass_count, const size_t spring_count) -> void
+{
+    update_texture_sizes();
+
+    draw_mass_springs(masses);
+    draw_klotski();
+    draw_menu();
+    draw_textures(fps, ups, mass_count, spring_count);
 }

src/state.cpp

@@ -1,281 +0,0 @@
-#include "state.hpp"
-#include "config.hpp"
-#include "distance.hpp"
-
-#include <fstream>
-#include <ios>
-#include <print>
-#include <raymath.h>
-
-#ifdef TRACY
-#include "tracy.hpp"
-#include <tracy/Tracy.hpp>
-#endif
-
-auto StateManager::ParsePresetFile(const std::string &_preset_file) -> bool {
-  preset_file = _preset_file;
-
-  std::ifstream file(preset_file);
-  if (!file) {
-    std::println("Preset file \"{}\" couldn't be loaded.", preset_file);
-    return false;
-  }
-
-  std::string line;
-  std::vector<std::string> comment_lines;
-  std::vector<std::string> preset_lines;
-  while (std::getline(file, line)) {
-    if (line.starts_with("F") || line.starts_with("R")) {
-      preset_lines.push_back(line);
-    } else if (line.starts_with("#")) {
-      comment_lines.push_back(line);
-    }
-  }
-
-  if (preset_lines.size() == 0 || comment_lines.size() != preset_lines.size()) {
-    std::println("Preset file \"{}\" couldn't be loaded.", preset_file);
-    return false;
-  }
-
-  presets.clear();
-  for (const auto &preset : preset_lines) {
-    presets.emplace_back(preset);
-  }
-  comments = comment_lines;
-
-  std::println("Loaded {} presets from \"{}\".", preset_lines.size(),
-               preset_file);
-
-  return true;
-}
-
-auto StateManager::AppendPresetFile(const std::string preset_name) -> void {
-  std::println("Saving preset \"{}\" to \"{}\"", preset_name, preset_file);
-
-  std::ofstream file(preset_file, std::ios_base::app | std::ios_base::out);
-  if (!file) {
-    std::println("Preset file \"{}\" couldn't be loaded.", preset_file);
-    return;
-  }
-
-  file << "\n# " << preset_name << "\n" << current_state.state << std::flush;
-
-  std::println("Refreshing presets...");
-  if (ParsePresetFile(preset_file)) {
-    LoadPreset(presets.size() - 1);
-  }
-}
-
-auto StateManager::LoadPreset(int preset) -> void {
-  current_preset = preset;
-  current_state = presets.at(current_preset);
-  ClearGraph();
-  edited = false;
-}
-
-auto StateManager::ResetState() -> void {
-  current_state = presets.at(current_preset);
-  previous_state = current_state;
-  for (auto &[state, visits] : visited_states) {
-    visits = 0;
-  }
-  visited_states[current_state]++;
-  total_moves = 0;
-  if (edited) {
-    // We also need to clear the graph in case the state has been edited
-    // because the graph could contain states that are impossible to reach
-    // now.
-    ClearGraph();
-    edited = false;
-  }
-}
-
-auto StateManager::PreviousPreset() -> void {
-  LoadPreset((presets.size() + current_preset - 1) % presets.size());
-}
-
-auto StateManager::NextPreset() -> void {
-  LoadPreset((current_preset + 1) % presets.size());
-}
-
-auto StateManager::NextPath() -> void {
-  if (target_distances.Empty()) {
-    return;
-  }
-
-  // Already there
-  if (target_distances.distances[CurrentMassIndex()] == 0) {
-    return;
-  }
-
-  std::size_t parent = target_distances.parents[CurrentMassIndex()];
-  current_state = masses.at(parent);
-  FindTargetPath();
-}
-
-auto StateManager::FillGraph() -> void {
-#ifdef TRACY
-  ZoneScoped;
-#endif
-
-  ClearGraph();
-
-  std::pair<std::vector<State>,
-            std::vector<std::pair<std::size_t, std::size_t>>>
-      closure = current_state.Closure();
-
-  physics.ClearCmd();
-  physics.AddMassSpringsCmd(closure.first.size(), closure.second);
-  for (const State &state : closure.first) {
-    states.insert(std::make_pair(state, states.size()));
-    masses.insert(std::make_pair(states.size() - 1, state));
-  }
-  for (const auto &[from, to] : closure.second) {
-    springs.emplace_back(from, to);
-  }
-  FindWinningStates();
-  FindTargetDistances();
-  FindTargetPath();
-
-  // Sanity check. Both values need to be equal
-  // for (const auto &[mass, state] : masses) {
-  //   std::println("Masses: {}, States: {}", mass, states.at(state));
-  // }
-}
-
-auto StateManager::UpdateGraph() -> void {
-  if (previous_state == current_state) {
-    return;
-  }
-
-  if (!states.contains(current_state)) {
-    states.insert(std::make_pair(current_state, states.size()));
-    masses.insert(std::make_pair(states.size() - 1, current_state));
-    springs.emplace_back(states.at(current_state), states.at(previous_state));
-    physics.AddMassCmd();
-    physics.AddSpringCmd(states.at(current_state), states.at(previous_state));
-
-    if (current_state.IsWon()) {
-      winning_states.insert(current_state);
-    }
-    FindTargetDistances();
-  }
-
-  // Adds the element with 0 if it doesn't exist
-  visited_states[current_state]++;
-  total_moves++;
-
-  if (history.size() > 0 && history.top() == current_state) {
-    // We don't pop the stack when moving backwards to indicate if we need to
-    // push or pop here
-    history.pop();
-  } else {
-    history.push(previous_state);
-  }
-
-  FindTargetPath();
-  previous_state = current_state;
-}
-
-auto StateManager::ClearGraph() -> void {
-  states.clear();
-  winning_states.clear();
-  visited_states.clear();
-  masses.clear();
-  winning_path.clear();
-  springs.clear();
-  history = std::stack<State>();
-  target_distances.Clear();
-  physics.ClearCmd();
-
-  // Re-add the default stuff to the graph
-  states.insert(std::make_pair(current_state, states.size()));
-  masses.insert(std::make_pair(states.size() - 1, current_state));
-  visited_states.insert(std::make_pair(current_state, 1));
-  physics.AddMassCmd();
-
-  // These states are no longer in the graph
-  previous_state = current_state;
-  starting_state = current_state;
-}
-
-auto StateManager::FindWinningStates() -> void {
-  winning_states.clear();
-  for (const auto &[state, mass] : states) {
-    if (state.IsWon()) {
-      winning_states.insert(state);
-    }
-  }
-}
-
-auto StateManager::FindTargetDistances() -> void {
-#ifdef TRACY
-  ZoneScoped;
-#endif
-
-  if (springs.size() == 0 || winning_states.size() == 0) {
-    return;
-  }
-
-  // Find target indices
-  std::vector<std::size_t> targets;
-  targets.reserve(winning_states.size());
-  for (const auto &_state : winning_states) {
-    targets.push_back(states.at(_state));
-  }
-
-  target_distances = CalculateDistances(states.size(), springs, targets);
-
-  // std::println("Calculated {} distances to {} targets.",
-  //              target_distances.distances.size(), targets.size());
-}
-
-auto StateManager::FindTargetPath() -> void {
-  if (target_distances.Empty()) {
-    return;
-  }
-
-  winning_path = GetPath(target_distances, CurrentMassIndex());
-  // std::println("Nearest target is {} moves away.", winning_path.size());
-}
-
-auto StateManager::FindWorstState() -> State {
-  if (target_distances.Empty()) {
-    return current_state;
-  }
-
-  int max = 0;
-  int index = 0;
-  for (std::size_t i = 0; i < target_distances.distances.size(); ++i) {
-    if (target_distances.distances.at(i) > max) {
-      max = target_distances.distances.at(i);
-      index = i;
-    }
-  }
-
-  return masses.at(index);
-}
-
-auto StateManager::GoToWorst() -> void { current_state = FindWorstState(); }
-
-auto StateManager::GoToNearestTarget() -> void {
-  if (target_distances.Empty()) {
-    return;
-  }
-
-  current_state =
-      masses.at(target_distances.nearest_targets.at(CurrentMassIndex()));
-}
-
-auto StateManager::PopHistory() -> void {
-  if (history.size() == 0) {
-    return;
-  }
-
-  current_state = history.top();
-  // history.pop(); // Done in UpdateGraph();
-}
-
-auto StateManager::CurrentMassIndex() const -> std::size_t {
-  return states.at(current_state);
-}

src/state_manager.cpp

@@ -0,0 +1,492 @@
+#include "state_manager.hpp"
+#include "graph_distances.hpp"
+#include "util.hpp"
+
+#include <fstream>
+#include <ios>
+
+#ifdef TRACY
+#include <tracy/Tracy.hpp>
+#endif
+
+auto state_manager::synced_try_insert_state(const puzzle& state) -> size_t
+{
+    if (state_indices.contains(state)) {
+        return state_indices.at(state);
+    }
+
+    const size_t index = state_pool.size();
+    state_pool.emplace_back(state);
+    state_indices.emplace(state, index);
+    visit_counts[index] = 0;
+
+    // Queue an update to the physics engine state to keep in sync
+    physics.add_mass_cmd();
+
+    return index;
+}
+
+auto state_manager::synced_insert_link(size_t first_index, size_t second_index) -> void
+{
+    links.emplace_back(first_index, second_index);
+
+    // Queue an update to the physics engine state to keep in sync
+    physics.add_spring_cmd(first_index, second_index);
+}
+
+auto state_manager::synced_insert_statespace(const std::vector<puzzle>& states,
+                                             const std::vector<std::pair<size_t, size_t>>& _links) -> void
+{
+    if (!state_pool.empty() || !state_indices.empty() || !links.empty()) {
+        warnln("Inserting statespace but collections haven't been cleared");
+    }
+
+    for (const puzzle& state : states) {
+        const size_t index = state_pool.size();
+        state_pool.emplace_back(state);
+        state_indices.emplace(state, index);
+        visit_counts[index] = 0;
+    }
+    for (const auto& [from, to] : _links) {
+        links.emplace_back(from, to);
+    }
+
+    // Queue an update to the physics engine state to keep in sync
+    physics.add_mass_springs_cmd(state_pool.size(), links);
+}
+
+auto state_manager::synced_clear_statespace() -> void
+{
+    // Those are invalid without any states
+    current_state_index = -1;
+    previous_state_index = -1;
+    starting_state_index = -1;
+
+    state_pool.clear();
+    state_indices.clear();
+    links.clear();
+    node_target_distances.clear();
+    winning_indices.clear();
+    winning_path.clear();
+    path_indices.clear();
+
+    move_history.clear();
+    visit_counts.clear();
+
+    // Queue an update to the physics engine state to keep in sync
+    physics.clear_cmd();
+}
+
+auto state_manager::parse_preset_file(const std::string& _preset_file) -> bool
+{
+    preset_file = _preset_file;
+
+    std::ifstream file(preset_file);
+    if (!file) {
+        infoln("Preset file \"{}\" couldn't be loaded.", preset_file);
+        return false;
+    }
+
+    std::string line;
+    std::vector<std::string> comment_lines;
+    std::vector<std::string> preset_lines;
+    while (std::getline(file, line)) {
+        if (line.starts_with("S")) {
+            preset_lines.push_back(line);
+        } else if (line.starts_with("#")) {
+            comment_lines.push_back(line);
+        }
+    }
+
+    if (preset_lines.empty() || comment_lines.size() != preset_lines.size()) {
+        infoln("Preset file \"{}\" couldn't be loaded.", preset_file);
+        return false;
+    }
+
+    preset_states.clear();
+    for (const auto& preset : preset_lines) {
+        // Each char is a bit
+        const puzzle& p = puzzle(preset);
+
+        if (const std::optional<std::string>& reason = p.try_get_invalid_reason()) {
+            preset_states = {puzzle(4, 5, 0, 0, true, false)};
+            infoln("Preset file \"{}\" contained invalid presets: {}", preset_file, *reason);
+            return false;
+        }
+        preset_states.emplace_back(p);
+    }
+    preset_comments = comment_lines;
+
+    infoln("Loaded {} presets from \"{}\".", preset_lines.size(), preset_file);
+
+    return true;
+}
+
+auto state_manager::append_preset_file(const std::string& preset_name) -> bool
+{
+    infoln(R"(Saving preset "{}" to "{}")", preset_name, preset_file);
+
+    if (get_current_state().try_get_invalid_reason()) {
+        return false;
+    }
+
+    std::ofstream file(preset_file, std::ios_base::app | std::ios_base::out);
+    if (!file) {
+        infoln("Preset file \"{}\" couldn't be loaded.", preset_file);
+        return false;
+    }
+
+    file << "\n# " << preset_name << "\n" << get_current_state().string_repr() << std::flush;
+
+    infoln("Refreshing presets...");
+    if (parse_preset_file(preset_file)) {
+        load_preset(preset_states.size() - 1);
+    }
+
+    return true;
+}
+
+auto state_manager::load_preset(const size_t preset) -> void
+{
+    clear_graph_and_add_current(preset_states.at(preset));
+    current_preset = preset;
+    edited = false;
+}
+
+auto state_manager::load_previous_preset() -> void
+{
+    load_preset((preset_states.size() + current_preset - 1) % preset_states.size());
+}
+
+auto state_manager::load_next_preset() -> void
+{
+    load_preset((current_preset + 1) % preset_states.size());
+}
+
+auto state_manager::update_current_state(const puzzle& p) -> void
+{
+    if (!p.valid()) {
+        return;
+    }
+
+    const size_t size_before = state_pool.size();
+
+    // If state is a duplicate, index will be the existing index,
+    // if state is new, index will be state_pool.size() - 1
+    const size_t index = synced_try_insert_state(p);
+
+    // Because synced_insert_link does not check for duplicates we do it here,
+    // if the size grows, it was not a duplicate, and we can add the spring
+    if (state_pool.size() > size_before) {
+        // The order is important, as the position of the second mass will be updated depending on
+        // the first
+        synced_insert_link(current_state_index, index);
+    }
+
+    previous_state_index = current_state_index;
+    current_state_index = index;
+
+    if (current_state_index != previous_state_index) {
+        move_history.emplace_back(previous_state_index);
+    }
+
+    if (p.goal_reached()) {
+        winning_indices.insert(current_state_index);
+    }
+
+    // Adds the element with 0 if it doesn't exist
+    visit_counts[current_state_index]++;
+    total_moves++;
+
+    // Recalculate distances only if the graph changed
+    if (state_pool.size() > size_before) {
+        populate_node_target_distances();
+    }
+    populate_winning_path();
+}
+
+auto state_manager::edit_starting_state(const puzzle& p) -> void
+{
+    clear_graph_and_add_current(p);
+
+    move_history.clear();
+    total_moves = 0;
+    for (int& visits : visit_counts | std::views::values) {
+        visits = 0;
+    }
+    visit_counts[current_state_index]++;
+
+    edited = true;
+}
+
+auto state_manager::goto_starting_state() -> void
+{
+    update_current_state(get_state(starting_state_index));
+
+    // Reset previous movement data since we're starting over (because we're fucking stupid)
+    previous_state_index = current_state_index;
+    for (int& visits : visit_counts | std::views::values) {
+        visits = 0;
+    }
+    visit_counts[current_state_index]++;
+    move_history.clear();
+    total_moves = 0;
+}
+
+auto state_manager::goto_optimal_next_state() -> void
+{
+    if (node_target_distances.empty()) {
+        return;
+    }
+
+    // Already there
+    if (node_target_distances.distances[current_state_index] == 0) {
+        return;
+    }
+
+    const size_t parent_index = node_target_distances.parents[current_state_index];
+    update_current_state(get_state(parent_index));
+}
+
+auto state_manager::goto_previous_state() -> void
+{
+    if (move_history.empty()) {
+        return;
+    }
+
+    update_current_state(get_state(move_history.back()));
+
+    // Pop twice because update_current_state adds the state again...
+    move_history.pop_back();
+    move_history.pop_back();
+}
+
+auto state_manager::goto_most_distant_state() -> void
+{
+    if (node_target_distances.empty()) {
+        return;
+    }
+
+    int max_distance = 0;
+    size_t max_distance_index = 0;
+    for (size_t i = 0; i < node_target_distances.distances.size(); ++i) {
+        if (node_target_distances.distances.at(i) > max_distance) {
+            max_distance = node_target_distances.distances.at(i);
+            max_distance_index = i;
+        }
+    }
+
+    update_current_state(get_state(max_distance_index));
+}
+
+auto state_manager::goto_closest_target_state() -> void
+{
+    if (node_target_distances.empty()) {
+        return;
+    }
+
+    update_current_state(get_state(node_target_distances.nearest_targets.at(current_state_index)));
+}
+
+auto state_manager::populate_graph() -> void
+{
+    #ifdef TRACY
+    ZoneScoped;
+    #endif
+
+    // Need to make a copy before clearing the state_pool
+    const puzzle s = get_starting_state();
+    const puzzle p = get_current_state();
+
+
+    // Clear the graph first so we don't add duplicates somehow
+    synced_clear_statespace();
+
+    // Explore the entire statespace starting from the current state
+    const auto& [states, _links] = s.explore_state_space();
+    synced_insert_statespace(states, _links);
+
+    current_state_index = state_indices.at(p);
+    previous_state_index = current_state_index;
+    starting_state_index = state_indices.at(s);
+
+    // Search for cool stuff
+    populate_winning_indices();
+    populate_node_target_distances();
+    populate_winning_path();
+}
+
+auto state_manager::clear_graph_and_add_current(const puzzle& p) -> void
+{
+    // We need to make a copy before clearing the state_pool
+    const puzzle _p = p; // NOLINT(*-unnecessary-copy-initialization)
+
+    synced_clear_statespace();
+
+    // Re-add the current state
+    current_state_index = synced_try_insert_state(_p);
+
+    // These states are no longer in the graph
+    previous_state_index = current_state_index;
+    starting_state_index = current_state_index;
+
+    visit_counts[current_state_index]++;
+}
+
+auto state_manager::clear_graph_and_add_current() -> void
+{
+    clear_graph_and_add_current(get_current_state());
+}
+
+auto state_manager::populate_winning_indices() -> void
+{
+    winning_indices.clear();
+    for (const auto& [state, index] : state_indices) {
+        if (state.goal_reached()) {
+            winning_indices.insert(index);
+        }
+    }
+}
+
+auto state_manager::populate_node_target_distances() -> void
+{
+    #ifdef TRACY
+    ZoneScoped;
+    #endif
+
+    if (links.empty() || winning_indices.empty()) {
+        return;
+    }
+
+    const std::vector<size_t> targets(winning_indices.begin(), winning_indices.end());
+    node_target_distances.calculate_distances(state_pool.size(), links, targets);
+}
+
+auto state_manager::populate_winning_path() -> void
+{
+    if (node_target_distances.empty()) {
+        return;
+    }
+
+    winning_path = node_target_distances.get_shortest_path(current_state_index);
+
+    path_indices.clear();
+    for (const size_t index : winning_path) {
+        path_indices.insert(index);
+    }
+}
+
+auto state_manager::get_index(const puzzle& state) const -> size_t
+{
+    return state_indices.at(state);
+}
+
+auto state_manager::get_current_index() const -> size_t
+{
+    return current_state_index;
+}
+
+auto state_manager::get_starting_index() const -> size_t
+{
+    return starting_state_index;
+}
+
+auto state_manager::get_state(const size_t index) const -> const puzzle&
+{
+    return state_pool.at(index);
+}
+
+auto state_manager::get_current_state() const -> const puzzle&
+{
+    return get_state(current_state_index);
+}
+
+auto state_manager::get_starting_state() const -> const puzzle&
+{
+    return get_state(starting_state_index);
+}
+
+auto state_manager::get_state_count() const -> size_t
+{
+    return state_pool.size();
+}
+
+auto state_manager::get_target_count() const -> size_t
+{
+    return winning_indices.size();
+}
+
+auto state_manager::get_link_count() const -> size_t
+{
+    return links.size();
+}
+
+auto state_manager::get_path_length() const -> size_t
+{
+    return winning_path.size();
+}
+
+auto state_manager::get_links() const -> const std::vector<std::pair<size_t, size_t>>&
+{
+    return links;
+}
+
+auto state_manager::get_winning_indices() const -> const boost::unordered_flat_set<size_t>&
+{
+    return winning_indices;
+}
+
+auto state_manager::get_visit_counts() const -> const boost::unordered_flat_map<size_t, int>&
+{
+    return visit_counts;
+}
+
+auto state_manager::get_winning_path() const -> const std::vector<size_t>&
+{
+    return winning_path;
+}
+
+auto state_manager::get_path_indices() const -> const boost::unordered_flat_set<size_t>&
+{
+    return path_indices;
+}
+
+auto state_manager::get_current_visits() const -> int
+{
+    return visit_counts.at(current_state_index);
+}
+
+auto state_manager::get_current_preset() const -> size_t
+{
+    return current_preset;
+}
+
+auto state_manager::get_preset_count() const -> size_t
+{
+    return preset_states.size();
+}
+
+auto state_manager::get_current_preset_comment() const -> const std::string&
+{
+    return preset_comments.at(current_preset);
+}
+
+auto state_manager::has_history() const -> bool
+{
+    return !move_history.empty();
+}
+
+auto state_manager::has_distances() const -> bool
+{
+    return !node_target_distances.empty();
+}
+
+auto state_manager::get_total_moves() const -> size_t
+{
+    return total_moves;
+}
+
+auto state_manager::was_edited() const -> bool
+{
+    return edited;
+}

src/threaded_physics.cpp

@@ -0,0 +1,194 @@
+#include "threaded_physics.hpp"
+#include "config.hpp"
+#include "mass_spring_system.hpp"
+
+#include <chrono>
+#include <raylib.h>
+#include <raymath.h>
+#include <utility>
+#include <vector>
+
+#ifdef TRACY
+#include <tracy/Tracy.hpp>
+#endif
+
+auto threaded_physics::physics_thread(physics_state& state) -> void
+{
+    #ifdef THREADPOOL
+    BS::this_thread::set_os_thread_name("physics");
+    #endif
+
+    mass_spring_system mass_springs;
+
+    const auto visitor = overloads{
+        [&](const struct add_mass& am)
+        {
+            mass_springs.add_mass();
+        },
+        [&](const struct add_spring& as)
+        {
+            mass_springs.add_spring(as.a, as.b);
+        },
+        [&](const struct clear_graph& cg)
+        {
+            mass_springs.clear();
+        },
+    };
+
+    std::chrono::time_point last = std::chrono::high_resolution_clock::now();
+    std::chrono::duration<double> physics_accumulator(0);
+    std::chrono::duration<double> ups_accumulator(0);
+    int loop_iterations = 0;
+
+    while (state.running.load()) {
+        #ifdef TRACY
+        FrameMarkStart("PhysicsThread");
+        #endif
+
+        // Time tracking
+        std::chrono::time_point now = std::chrono::high_resolution_clock::now();
+        const std::chrono::duration<double> deltatime = now - last;
+        physics_accumulator += deltatime;
+        ups_accumulator += deltatime;
+        last = now;
+
+        // Handle queued commands
+        {
+            #ifdef TRACY
+            std::lock_guard<LockableBase(std::mutex)> lock(state.command_mtx);
+            #else
+            std::lock_guard<std::mutex> lock(state.command_mtx);
+            #endif
+            while (!state.pending_commands.empty()) {
+                command& cmd = state.pending_commands.front();
+                cmd.visit(visitor);
+                state.pending_commands.pop();
+            }
+        }
+
+        if (mass_springs.masses.empty()) {
+            std::this_thread::sleep_for(std::chrono::milliseconds(1));
+            continue;
+        }
+
+        // Physics update
+        if (physics_accumulator.count() > TIMESTEP) {
+            mass_springs.clear_forces();
+            mass_springs.calculate_spring_forces();
+            mass_springs.calculate_repulsion_forces();
+            mass_springs.verlet_update(TIMESTEP * SIM_SPEED);
+
+            // This is only helpful if we're drawing a grid at (0, 0, 0). Otherwise, it's just
+            // expensive and yields no benefit since we can lock the camera to the center of mass
+            // cheaply. mass_springs.center_masses();
+
+            ++loop_iterations;
+            physics_accumulator -= std::chrono::duration<double>(TIMESTEP);
+        }
+
+        // Publish the positions for the renderer (copy)
+        #ifdef TRACY
+        FrameMarkStart("PhysicsThreadProduceLock");
+        #endif
+        {
+            #ifdef TRACY
+            std::unique_lock<LockableBase(std::mutex)> lock(state.data_mtx);
+            #else
+            std::unique_lock<std::mutex> lock(state.data_mtx);
+            #endif
+            state.data_consumed_cnd.wait(lock, [&]
+            {
+                return state.data_consumed || !state.running.load();
+            });
+            if (!state.running.load()) {
+                // Running turned false while we were waiting for the condition
+                break;
+            }
+
+            if (ups_accumulator.count() > 1.0) {
+                // Update each second
+                state.ups = loop_iterations;
+                loop_iterations = 0;
+                ups_accumulator = std::chrono::duration<double>(0);
+            }
+            if (mass_springs.tree.nodes.empty()) {
+                state.mass_center = Vector3Zero();
+            } else {
+                state.mass_center = mass_springs.tree.nodes.at(0).mass_center;
+            }
+
+            state.masses.clear();
+            state.masses.reserve(mass_springs.masses.size());
+            for (const auto& mass : mass_springs.masses) {
+                state.masses.emplace_back(mass.position);
+            }
+
+            state.mass_count = mass_springs.masses.size();
+            state.spring_count = mass_springs.springs.size();
+
+            state.data_ready = true;
+            state.data_consumed = false;
+        }
+        // Notify the rendering thread that new data is available
+        state.data_ready_cnd.notify_all();
+        #ifdef TRACY
+        FrameMarkEnd("PhysicsThreadProduceLock");
+
+        FrameMarkEnd("PhysicsThread");
+        #endif
+    }
+}
+
+auto threaded_physics::add_mass_cmd() -> void
+{
+    {
+        #ifdef TRACY
+        std::lock_guard<LockableBase(std::mutex)> lock(state.command_mtx);
+        #else
+        std::lock_guard<std::mutex> lock(state.command_mtx);
+        #endif
+        state.pending_commands.emplace(add_mass{});
+    }
+}
+
+auto threaded_physics::add_spring_cmd(const size_t a, const size_t b) -> void
+{
+    {
+        #ifdef TRACY
+        std::lock_guard<LockableBase(std::mutex)> lock(state.command_mtx);
+        #else
+        std::lock_guard<std::mutex> lock(state.command_mtx);
+        #endif
+        state.pending_commands.emplace(add_spring{a, b});
+    }
+}
+
+auto threaded_physics::clear_cmd() -> void
+{
+    {
+        #ifdef TRACY
+        std::lock_guard<LockableBase(std::mutex)> lock(state.command_mtx);
+        #else
+        std::lock_guard<std::mutex> lock(state.command_mtx);
+        #endif
+        state.pending_commands.emplace(clear_graph{});
+    }
+}
+
+auto threaded_physics::add_mass_springs_cmd(const size_t num_masses,
+                                            const std::vector<std::pair<size_t, size_t>>& springs) -> void
+{
+    {
+        #ifdef TRACY
+        std::lock_guard<LockableBase(std::mutex)> lock(state.command_mtx);
+        #else
+        std::lock_guard<std::mutex> lock(state.command_mtx);
+        #endif
+        for (size_t i = 0; i < num_masses; ++i) {
+            state.pending_commands.emplace(add_mass{});
+        }
+        for (const auto& [from, to] : springs) {
+            state.pending_commands.emplace(add_spring{from, to});
+        }
+    }
+}

src/tracy.cpp

@@ -1,22 +0,0 @@
-#include "config.hpp"
-
-#ifdef TRACY
-
-#include "tracy.hpp"
-#include <tracy/Tracy.hpp>
-
-void *operator new(std::size_t count) {
-  auto ptr = malloc(count);
-  TracyAllocS(ptr, count, 20);
-  return ptr;
-}
-void operator delete(void *ptr) noexcept {
-  TracyFreeS(ptr, 20);
-  free(ptr);
-}
-void operator delete(void *ptr, std::size_t count) noexcept {
-  TracyFreeS(ptr, 20);
-  free(ptr);
-}
-
-#endif

src/user_interface.cpp

@@ -0,0 +1,867 @@
+#include "user_interface.hpp"
+#include "config.hpp"
+#include "input_handler.hpp"
+
+#include <raylib.h>
+
+#define RAYGUI_IMPLEMENTATION
+#include <raygui.h>
+
+#ifdef TRACY
+#include <tracy/Tracy.hpp>
+#endif
+
+auto user_interface::grid::update_bounds(const int _x, const int _y, const int _width, const int _height,
+                                         const int _columns, const int _rows) -> void
+{
+    x = _x;
+    y = _y;
+    width = _width;
+    height = _height;
+    columns = _columns;
+    rows = _rows;
+}
+
+auto user_interface::grid::update_bounds(const int _x, const int _y, const int _width, const int _height) -> void
+{
+    x = _x;
+    y = _y;
+    width = _width;
+    height = _height;
+}
+
+auto user_interface::grid::update_bounds(const int _x, const int _y) -> void
+{
+    x = _x;
+    y = _y;
+}
+
+auto user_interface::grid::bounds() const -> Rectangle
+{
+    Rectangle bounds{0, 0, static_cast<float>(columns), static_cast<float>(rows)};
+    bounds.x -= padding;
+    bounds.y -= padding;
+    bounds.width += 2 * padding;
+    bounds.height += 2 * padding;
+    return bounds;
+}
+
+auto user_interface::grid::bounds(const int _x, const int _y, const int _width, const int _height) const -> Rectangle
+{
+    if (_x < 0 || _x + _width > columns || _y < 0 || _y + _height > rows) {
+        throw std::invalid_argument("Grid bounds out of range");
+    }
+
+    const int cell_width = (width - padding) / columns;
+    const int cell_height = (height - padding) / rows;
+
+    return Rectangle(x + _x * cell_width + padding, y + _y * cell_height + padding, _width * cell_width - padding,
+                     _height * cell_height - padding);
+}
+
+auto user_interface::grid::square_bounds() const -> Rectangle
+{
+    Rectangle bounds = square_bounds(0, 0, columns, rows);
+    bounds.x -= padding;
+    bounds.y -= padding;
+    bounds.width += 2 * padding;
+    bounds.height += 2 * padding;
+    return bounds;
+}
+
+auto user_interface::grid::square_bounds(const int _x, const int _y, const int _width,
+                                         const int _height) const -> Rectangle
+{
+    // Assumes each cell is square, so either width or height are not completely
+    // filled
+
+    if (_x < 0 || _x + _width > columns || _y < 0 || _y + _height > rows) {
+        throw std::invalid_argument("Grid bounds out of range");
+    }
+
+    const int available_width = width - padding * (columns + 1);
+    const int available_height = height - padding * (rows + 1);
+    const int cell_size = std::min(available_width / columns, available_height / rows);
+
+    const int grid_width = cell_size * columns + padding * (columns + 1);
+    const int grid_height = cell_size * rows + padding * (rows + 1);
+    const int x_offset = (width - grid_width) / 2;
+    const int y_offset = (height - grid_height) / 2;
+
+    return Rectangle(x_offset + _x * (cell_size + padding) + padding, y_offset + _y * (cell_size + padding) + padding,
+                     _width * cell_size + padding * (_width - 1), _height * cell_size + padding * (_height - 1));
+}
+
+auto user_interface::init() -> void
+{
+    const Font font = LoadFontEx(FONT, FONT_SIZE, nullptr, 0);
+    SetTextureFilter(font.texture, TEXTURE_FILTER_BILINEAR);
+    GuiSetFont(font);
+
+    default_style style = get_default_style();
+    style.text_size = FONT_SIZE;
+    apply_color(style, GRAY);
+
+    set_default_style(style);
+}
+
+auto user_interface::apply_color(style& style, const Color color) -> void
+{
+    style.base_color_normal = ColorToInt(Fade(color, 0.8));
+    style.base_color_focused = ColorToInt(Fade(color, 0.3));
+    style.base_color_pressed = ColorToInt(Fade(color, 0.8));
+    style.base_color_disabled = ColorToInt(Fade(color, 0.5));
+
+    style.border_color_normal = ColorToInt(Fade(color, 1.0));
+    style.border_color_focused = ColorToInt(Fade(color, 0.7));
+    style.border_color_pressed = ColorToInt(Fade(color, 1.0));
+    style.border_color_disabled = ColorToInt(Fade(GRAY, 0.5));
+
+    style.text_color_normal = ColorToInt(Fade(BLACK, 1.0));
+    style.text_color_focused = ColorToInt(Fade(BLACK, 1.0));
+    style.text_color_pressed = ColorToInt(Fade(BLACK, 1.0));
+    style.text_color_disabled = ColorToInt(Fade(BLACK, 0.5));
+}
+
+auto user_interface::apply_block_color(style& style, const Color color) -> void
+{
+    style.base_color_normal = ColorToInt(Fade(color, 0.5));
+    style.base_color_focused = ColorToInt(Fade(color, 0.3));
+    style.base_color_pressed = ColorToInt(Fade(color, 0.8));
+    style.base_color_disabled = ColorToInt(Fade(color, 0.5));
+
+    style.border_color_normal = ColorToInt(Fade(color, 1.0));
+    style.border_color_focused = ColorToInt(Fade(color, 0.7));
+    style.border_color_pressed = ColorToInt(Fade(color, 1.0));
+    style.border_color_disabled = ColorToInt(Fade(GRAY, 0.5));
+}
+
+auto user_interface::apply_text_color(style& style, const Color color) -> void
+{
+    style.text_color_normal = ColorToInt(Fade(color, 1.0));
+    style.text_color_focused = ColorToInt(Fade(color, 1.0));
+    style.text_color_pressed = ColorToInt(Fade(color, 1.0));
+    style.text_color_disabled = ColorToInt(Fade(BLACK, 0.5));
+}
+
+auto user_interface::get_default_style() -> default_style
+{
+    // Could've iterated over the values, but then it wouldn't be as nice to
+    // access...
+    return {
+        {
+            GuiGetStyle(DEFAULT, BORDER_COLOR_NORMAL), GuiGetStyle(DEFAULT, BASE_COLOR_NORMAL),
+            GuiGetStyle(DEFAULT, TEXT_COLOR_NORMAL), GuiGetStyle(DEFAULT, BORDER_COLOR_FOCUSED),
+            GuiGetStyle(DEFAULT, BASE_COLOR_FOCUSED), GuiGetStyle(DEFAULT, TEXT_COLOR_FOCUSED),
+            GuiGetStyle(DEFAULT, BORDER_COLOR_PRESSED), GuiGetStyle(DEFAULT, BASE_COLOR_PRESSED),
+            GuiGetStyle(DEFAULT, TEXT_COLOR_PRESSED), GuiGetStyle(DEFAULT, BORDER_COLOR_DISABLED),
+            GuiGetStyle(DEFAULT, BASE_COLOR_DISABLED), GuiGetStyle(DEFAULT, TEXT_COLOR_DISABLED)
+        },
+        GuiGetStyle(DEFAULT, BACKGROUND_COLOR), GuiGetStyle(DEFAULT, LINE_COLOR), GuiGetStyle(DEFAULT, TEXT_SIZE),
+        GuiGetStyle(DEFAULT, TEXT_SPACING), GuiGetStyle(DEFAULT, TEXT_LINE_SPACING),
+        GuiGetStyle(DEFAULT, TEXT_ALIGNMENT_VERTICAL), GuiGetStyle(DEFAULT, TEXT_WRAP_MODE)
+    };
+}
+
+auto user_interface::set_default_style(const default_style& style) -> void
+{
+    GuiSetStyle(DEFAULT, BORDER_COLOR_NORMAL, style.border_color_normal);
+    GuiSetStyle(DEFAULT, BASE_COLOR_NORMAL, style.base_color_normal);
+    GuiSetStyle(DEFAULT, TEXT_COLOR_NORMAL, style.text_color_normal);
+
+    GuiSetStyle(DEFAULT, BORDER_COLOR_FOCUSED, style.border_color_focused);
+    GuiSetStyle(DEFAULT, BASE_COLOR_FOCUSED, style.base_color_focused);
+    GuiSetStyle(DEFAULT, TEXT_COLOR_FOCUSED, style.text_color_focused);
+
+    GuiSetStyle(DEFAULT, BORDER_COLOR_PRESSED, style.border_color_pressed);
+    GuiSetStyle(DEFAULT, BASE_COLOR_PRESSED, style.base_color_pressed);
+    GuiSetStyle(DEFAULT, TEXT_COLOR_PRESSED, style.text_color_pressed);
+
+    GuiSetStyle(DEFAULT, BORDER_COLOR_DISABLED, style.border_color_disabled);
+    GuiSetStyle(DEFAULT, BASE_COLOR_DISABLED, style.base_color_disabled);
+    GuiSetStyle(DEFAULT, TEXT_COLOR_DISABLED, style.text_color_disabled);
+
+    GuiSetStyle(DEFAULT, BACKGROUND_COLOR, style.background_color);
+    GuiSetStyle(DEFAULT, LINE_COLOR, style.line_color);
+
+    GuiSetStyle(DEFAULT, TEXT_SIZE, style.text_size);
+    GuiSetStyle(DEFAULT, TEXT_SPACING, style.text_spacing);
+    GuiSetStyle(DEFAULT, TEXT_LINE_SPACING, style.text_line_spacing);
+    GuiSetStyle(DEFAULT, TEXT_ALIGNMENT_VERTICAL, style.text_alignment_vertical);
+    GuiSetStyle(DEFAULT, TEXT_WRAP_MODE, style.text_wrap_mode);
+}
+
+auto user_interface::get_component_style(const int component) -> component_style
+{
+    return {
+        {
+            GuiGetStyle(component, BORDER_COLOR_NORMAL), GuiGetStyle(component, BASE_COLOR_NORMAL),
+            GuiGetStyle(component, TEXT_COLOR_NORMAL), GuiGetStyle(component, BORDER_COLOR_FOCUSED),
+            GuiGetStyle(component, BASE_COLOR_FOCUSED), GuiGetStyle(component, TEXT_COLOR_FOCUSED),
+            GuiGetStyle(component, BORDER_COLOR_PRESSED), GuiGetStyle(component, BASE_COLOR_PRESSED),
+            GuiGetStyle(component, TEXT_COLOR_PRESSED), GuiGetStyle(component, BORDER_COLOR_DISABLED),
+            GuiGetStyle(component, BASE_COLOR_DISABLED), GuiGetStyle(component, TEXT_COLOR_DISABLED)
+        },
+        GuiGetStyle(component, BORDER_WIDTH), GuiGetStyle(component, TEXT_PADDING),
+        GuiGetStyle(component, TEXT_ALIGNMENT)
+    };
+}
+
+auto user_interface::set_component_style(const int component, const component_style& style) -> void
+{
+    GuiSetStyle(component, BORDER_COLOR_NORMAL, style.border_color_normal);
+    GuiSetStyle(component, BASE_COLOR_NORMAL, style.base_color_normal);
+    GuiSetStyle(component, TEXT_COLOR_NORMAL, style.text_color_normal);
+
+    GuiSetStyle(component, BORDER_COLOR_FOCUSED, style.border_color_focused);
+    GuiSetStyle(component, BASE_COLOR_FOCUSED, style.base_color_focused);
+    GuiSetStyle(component, TEXT_COLOR_FOCUSED, style.text_color_focused);
+
+    GuiSetStyle(component, BORDER_COLOR_PRESSED, style.border_color_pressed);
+    GuiSetStyle(component, BASE_COLOR_PRESSED, style.base_color_pressed);
+    GuiSetStyle(component, TEXT_COLOR_PRESSED, style.text_color_pressed);
+
+    GuiSetStyle(component, BORDER_COLOR_DISABLED, style.border_color_disabled);
+    GuiSetStyle(component, BASE_COLOR_DISABLED, style.base_color_disabled);
+    GuiSetStyle(component, TEXT_COLOR_DISABLED, style.text_color_disabled);
+
+    GuiSetStyle(component, BORDER_WIDTH, style.border_width);
+    GuiSetStyle(component, TEXT_PADDING, style.text_padding);
+    GuiSetStyle(component, TEXT_ALIGNMENT, style.text_alignment);
+}
+
+auto user_interface::popup_bounds() -> Rectangle
+{
+    return Rectangle(static_cast<float>(GetScreenWidth()) / 2.0f - POPUP_WIDTH / 2.0f,
+                     static_cast<float>(GetScreenHeight()) / 2.0f - POPUP_HEIGHT / 2.0f, POPUP_WIDTH, POPUP_HEIGHT);
+}
+
+auto user_interface::draw_button(const Rectangle bounds, const std::string& label, const Color color,
+                                 const bool enabled, const int font_size) const -> int
+{
+    // Save original styling
+    const default_style original_default = get_default_style();
+    const component_style original_button = get_component_style(BUTTON);
+
+    // Change styling
+    default_style style_default = original_default;
+    component_style style_button = original_button;
+    style_default.text_size = font_size;
+    apply_color(style_button, color);
+    set_default_style(style_default);
+    set_component_style(BUTTON, style_button);
+
+    const int _state = GuiGetState();
+    if (!enabled || window_open()) {
+        GuiSetState(STATE_DISABLED);
+    }
+    const int pressed = GuiButton(bounds, label.data());
+    if (!enabled || window_open()) {
+        GuiSetState(_state);
+    }
+
+    // Restore original styling
+    set_default_style(original_default);
+    set_component_style(BUTTON, original_button);
+
+    return pressed;
+}
+
+auto user_interface::draw_menu_button(const int x, const int y, const int width, const int height,
+                                      const std::string& label, const Color color, const bool enabled,
+                                      const int font_size) const -> int
+{
+    const Rectangle bounds = menu_grid.bounds(x, y, width, height);
+    return draw_button(bounds, label, color, enabled, font_size);
+}
+
+auto user_interface::draw_toggle_slider(const Rectangle bounds, const std::string& off_label,
+                                        const std::string& on_label, int* active, Color color, bool enabled,
+                                        int font_size) const -> int
+{
+    // Save original styling
+    const default_style original_default = get_default_style();
+    const component_style original_slider = get_component_style(SLIDER);
+    const component_style original_toggle = get_component_style(TOGGLE);
+
+    // Change styling
+    default_style style_default = original_default;
+    component_style style_slider = original_slider;
+    component_style style_toggle = original_toggle;
+    style_default.text_size = font_size;
+    apply_color(style_slider, color);
+    apply_color(style_toggle, color);
+    set_default_style(style_default);
+    set_component_style(SLIDER, style_slider);
+    set_component_style(TOGGLE, style_toggle);
+
+    const int _state = GuiGetState();
+    if (!enabled || window_open()) {
+        GuiSetState(STATE_DISABLED);
+    }
+    int pressed = GuiToggleSlider(bounds, std::format("{};{}", off_label, on_label).data(), active);
+    if (!enabled || window_open()) {
+        GuiSetState(_state);
+    }
+
+    // Restore original styling
+    set_default_style(original_default);
+    set_component_style(SLIDER, original_slider);
+    set_component_style(TOGGLE, original_toggle);
+
+    return pressed;
+}
+
+auto user_interface::draw_menu_toggle_slider(const int x, const int y, const int width, const int height,
+                                             const std::string& off_label, const std::string& on_label, int* active,
+                                             const Color color, const bool enabled, const int font_size) const -> int
+{
+    const Rectangle bounds = menu_grid.bounds(x, y, width, height);
+    return draw_toggle_slider(bounds, off_label, on_label, active, color, enabled, font_size);
+}
+
+auto user_interface::draw_spinner(Rectangle bounds, const std::string& label, int* value, int min, int max, Color color,
+                                  bool enabled, int font_size) const -> int
+{
+    // Save original styling
+    const default_style original_default = get_default_style();
+    const component_style original_valuebox = get_component_style(VALUEBOX);
+    const component_style original_button = get_component_style(BUTTON);
+
+    // Change styling
+    default_style style_default = original_default;
+    component_style style_valuebox = original_valuebox;
+    component_style style_button = original_button;
+    style_default.text_size = font_size;
+    apply_color(style_valuebox, color);
+    apply_color(style_button, color);
+    set_default_style(style_default);
+    set_component_style(VALUEBOX, style_valuebox);
+    set_component_style(BUTTON, style_button);
+
+    const int _state = GuiGetState();
+    if (!enabled || window_open()) {
+        GuiSetState(STATE_DISABLED);
+    }
+    int pressed = GuiSpinner(bounds, "", label.data(), value, min, max, false);
+    if (!enabled || window_open()) {
+        GuiSetState(_state);
+    }
+
+    // Restore original styling
+    set_default_style(original_default);
+    set_component_style(VALUEBOX, original_valuebox);
+    set_component_style(BUTTON, style_button);
+
+    return pressed;
+}
+
+auto user_interface::draw_menu_spinner(const int x, const int y, const int width, const int height,
+                                       const std::string& label, int* value, const int min, const int max,
+                                       const Color color, const bool enabled, const int font_size) const -> int
+{
+    const Rectangle bounds = menu_grid.bounds(x, y, width, height);
+    return draw_spinner(bounds, label, value, min, max, color, enabled, font_size);
+}
+
+auto user_interface::draw_label(const Rectangle bounds, const std::string& text, const Color color, const bool enabled,
+                                const int font_size) const -> int
+{
+    // Save original styling
+    const default_style original_default = get_default_style();
+    const component_style original_label = get_component_style(LABEL);
+
+    // Change styling
+    default_style style_default = original_default;
+    component_style style_label = original_label;
+    style_default.text_size = font_size;
+    apply_text_color(style_label, color);
+    set_default_style(style_default);
+    set_component_style(LABEL, style_label);
+
+    const int _state = GuiGetState();
+    if (!enabled || window_open()) {
+        GuiSetState(STATE_DISABLED);
+    }
+    const int pressed = GuiLabel(bounds, text.data());
+    if (!enabled || window_open()) {
+        GuiSetState(_state);
+    }
+
+    // Restore original styling
+    set_default_style(original_default);
+    set_component_style(LABEL, original_label);
+
+    return pressed;
+}
+
+auto user_interface::draw_board_block(const int x, const int y, const int width, const int height, const Color color,
+                                      const bool enabled) const -> bool
+{
+    component_style s = get_component_style(BUTTON);
+    apply_block_color(s, color);
+
+    const Rectangle bounds = board_grid.square_bounds(x, y, width, height);
+
+    const bool focused = CheckCollisionPointRec(input.mouse - Vector2(0, MENU_HEIGHT), bounds);
+    const bool pressed = puzzle::block(x, y, width, height, false).covers(input.sel_x, input.sel_y);
+
+    // Background to make faded colors work
+    DrawRectangleRec(bounds, RAYWHITE);
+
+    Color base = GetColor(s.base_color_normal);
+    Color border = GetColor(s.base_color_normal);
+    if (pressed) {
+        base = GetColor(s.base_color_pressed);
+        border = GetColor(s.base_color_pressed);
+    }
+    if (focused) {
+        base = GetColor(s.base_color_focused);
+        border = GetColor(s.base_color_focused);
+    }
+    if (focused && IsMouseButtonDown(MOUSE_BUTTON_LEFT)) {
+        base = GetColor(s.base_color_pressed);
+        border = GetColor(s.base_color_pressed);
+    }
+    if (!enabled) {
+        base = BOARD_COLOR_RESTRICTED;
+    }
+    DrawRectangleRec(bounds, base);
+    if (enabled) {
+        DrawRectangleLinesEx(bounds, 2.0, border);
+    }
+
+    return focused && enabled;
+}
+
+auto user_interface::window_open() const -> bool
+{
+    return save_window || help_window || ok_message || yes_no_message;
+}
+
+auto user_interface::draw_menu_header(const Color color) const -> void
+{
+    int preset = static_cast<int>(state.get_current_preset());
+    draw_menu_spinner(0, 0, 1, 1, "Preset: ", &preset, -1, static_cast<int>(state.get_preset_count()), color,
+                      !input.editing);
+    if (preset > static_cast<int>(state.get_current_preset())) {
+        input.load_next_preset();
+    } else if (preset < static_cast<int>(state.get_current_preset())) {
+        input.load_previous_preset();
+    }
+
+    draw_menu_button(1, 0, 1, 1, std::format("{}: {}/{} Blocks",
+                                             state.was_edited()
+                                                 ? "Modified"
+                                                 : std::format("\"{}\"", state.get_current_preset_comment().substr(2)),
+                                             state.get_current_state().block_count(), puzzle::MAX_BLOCKS), color);
+
+    int editing = input.editing;
+    draw_menu_toggle_slider(2, 0, 1, 1, "Puzzle Mode (Tab)", "Edit Mode (Tab)", &editing, color);
+    if (editing != input.editing) {
+        input.toggle_editing();
+    }
+}
+
+auto user_interface::draw_graph_info(const Color color) const -> void
+{
+    draw_menu_button(0, 1, 1, 1, std::format("Found {} States ({} Winning)", state.get_state_count(),
+                                             state.get_target_count()), color);
+
+    draw_menu_button(1, 1, 1, 1, std::format("Found {} Transitions", state.get_link_count()), color);
+
+    draw_menu_button(2, 1, 1, 1, std::format("{} Moves to Nearest Solution",
+                                             state.get_path_length() > 0 ? state.get_path_length() - 1 : 0), color);
+}
+
+auto user_interface::draw_graph_controls(const Color color) const -> void
+{
+    if (draw_menu_button(0, 2, 1, 1, "Populate Graph (G)", color)) {
+        input.populate_graph();
+    }
+
+    // int mark_path = input.mark_path;
+    // DrawMenuToggleSlider(2, 2, 1, 1, "Path Hidden (U)", "Path Shown (U)",
+    //                      &mark_path, color);
+    // if (mark_path != input.mark_path) {
+    //   input.ToggleMarkPath();
+    // }
+
+    if (draw_menu_button(1, 2, 1, 1, "Clear Graph (C)", color)) {
+        input.clear_graph();
+    }
+
+    int mark_solutions = input.mark_solutions;
+    draw_menu_toggle_slider(2, 2, 1, 1, "Solution Hidden (I)", "Solution Shown (I)", &mark_solutions, color);
+    if (mark_solutions != input.mark_solutions) {
+        input.toggle_mark_solutions();
+    }
+    input.mark_path = input.mark_solutions;
+}
+
+auto user_interface::draw_camera_controls(const Color color) const -> void
+{
+    int lock_camera = input.camera_lock;
+    draw_menu_toggle_slider(0, 3, 1, 1, "Free Camera (L)", "Locked Camera (L)", &lock_camera, color);
+    if (lock_camera != input.camera_lock) {
+        input.toggle_camera_lock();
+    }
+
+    int lock_camera_mass_center = input.camera_mass_center_lock;
+    draw_menu_toggle_slider(1, 3, 1, 1, "Current Block (U)", "Graph Center (U)", &lock_camera_mass_center, color,
+                            input.camera_lock);
+    if (lock_camera_mass_center != input.camera_mass_center_lock) {
+        input.toggle_camera_mass_center_lock();
+    }
+
+    int projection = camera.projection == CAMERA_ORTHOGRAPHIC;
+    draw_menu_toggle_slider(2, 3, 1, 1, "Perspective (Alt)", "Orthographic (Alt)", &projection, color);
+    if (projection != (camera.projection == CAMERA_ORTHOGRAPHIC)) {
+        input.toggle_camera_projection();
+    }
+}
+
+auto user_interface::draw_puzzle_controls(const Color color) const -> void
+{
+    auto nth = [&](const int n)
+    {
+        if (n == 11 || n == 12 || n == 13) {
+            return "th";
+        }
+        if (n % 10 == 1) {
+            return "st";
+        }
+        if (n % 10 == 2) {
+            return "nd";
+        }
+        if (n % 10 == 3) {
+            return "rd";
+        }
+        return "th";
+    };
+
+    const int visits = state.get_current_visits();
+    draw_menu_button(0, 4, 1, 1, std::format("{} Moves ({}{} Time at this State)", state.get_total_moves(), visits,
+                                             nth(visits)), color);
+
+    if (draw_menu_button(1, 4, 1, 1, "Make Optimal Move (Space)", color, state.has_distances())) {
+        input.goto_optimal_next_state();
+    }
+
+    if (draw_menu_button(2, 4, 1, 1, "Undo Last Move (Backspace)", color, state.has_history())) {
+        input.goto_previous_state();
+    }
+
+    if (draw_menu_button(0, 5, 1, 1, "Go to Nearest Solution (B)", color, state.has_distances())) {
+        input.goto_closest_target_state();
+    }
+
+    if (draw_menu_button(1, 5, 1, 1, "Go to Worst State (V)", color, state.has_distances())) {
+        input.goto_most_distant_state();
+    }
+
+    if (draw_menu_button(2, 5, 1, 1, "Go to Starting State (R)", color,
+                         state.get_current_index() != state.get_starting_index())) {
+        input.goto_starting_state();
+    }
+}
+
+auto user_interface::draw_edit_controls(const Color color) const -> void
+{
+    const puzzle& current = state.get_current_state();
+
+    // Toggle Target Block
+    if (draw_menu_button(0, 4, 1, 1, "Toggle Target Block (T)", color)) {
+        input.toggle_target_block();
+    }
+
+    // Toggle Wall Block
+    if (draw_menu_button(0, 5, 1, 1, "Toggle Wall Block (Y)", color)) {
+        input.toggle_wall_block();
+    }
+
+    // Toggle Restricted/Free Block Movement
+    int free = !current.get_restricted();
+    draw_menu_toggle_slider(1, 4, 1, 1, "Restricted (F)", "Free (F)", &free, color);
+    if (free != !current.get_restricted()) {
+        input.toggle_restricted_movement();
+    }
+
+    // Clear Goal
+    if (draw_menu_button(1, 5, 1, 1, "Clear Goal (X)", color)) {}
+
+    // Column Count Spinner
+    int columns = current.get_width();
+    draw_menu_spinner(2, 4, 1, 1, "Cols: ", &columns, puzzle::MIN_WIDTH, puzzle::MAX_WIDTH, color);
+    if (columns > current.get_width()) {
+        input.add_board_column();
+    } else if (columns < current.get_width()) {
+        input.remove_board_column();
+    }
+
+    // Row Count Spinner
+    int rows = current.get_height();
+    draw_menu_spinner(2, 5, 1, 1, "Rows: ", &rows, puzzle::MIN_WIDTH, puzzle::MAX_WIDTH, color);
+    if (rows > current.get_height()) {
+        input.add_board_row();
+    } else if (rows < current.get_height()) {
+        input.remove_board_row();
+    }
+}
+
+auto user_interface::draw_menu_footer(const Color color) -> void
+{
+    draw_menu_button(0, 6, 2, 1, state.get_current_state().string_repr().data(), color);
+
+    if (draw_menu_button(2, 6, 1, 1, "Save as Preset", color)) {
+        if (const std::optional<std::string>& reason = state.get_current_state().try_get_invalid_reason()) {
+            message_title = "Can't Save Preset";
+            message_message = std::format("Invalid Board: {}.", *reason);
+            ok_message = true;
+        } else {
+            save_window = true;
+        }
+    }
+}
+
+auto user_interface::get_background_color() -> Color
+{
+    return GetColor(GuiGetStyle(DEFAULT, BACKGROUND_COLOR));
+}
+
+auto user_interface::help_popup() -> void {}
+
+auto user_interface::draw_save_preset_popup() -> void
+{
+    if (!save_window) {
+        return;
+    }
+
+    // Returns the pressed button index
+    const int button = GuiTextInputBox(popup_bounds(), "Save as Preset", "Enter Preset Name", "Ok;Cancel",
+                                       preset_name.data(), 255, nullptr);
+    if (button == 1) {
+        state.append_preset_file(preset_name.data());
+    }
+    if (button == 0 || button == 1 || button == 2) {
+        save_window = false;
+        TextCopy(preset_name.data(), "\0");
+    }
+}
+
+auto user_interface::draw_ok_message_box() -> void
+{
+    if (!ok_message) {
+        return;
+    }
+
+    const int button = GuiMessageBox(popup_bounds(), message_title.data(), message_message.data(), "Ok");
+    if (button == 0 || button == 1) {
+        message_title = "";
+        message_message = "";
+        ok_message = false;
+    }
+}
+
+auto user_interface::draw_yes_no_message_box() -> void
+{
+    if (!yes_no_message) {
+        return;
+    }
+
+    const int button = GuiMessageBox(popup_bounds(), message_title.data(), message_message.data(), "Yes;No");
+    if (button == 1) {
+        yes_no_handler();
+    }
+    if (button == 0 || button == 1 || button == 2) {
+        message_title = "";
+        message_message = "";
+        yes_no_message = false;
+    }
+}
+
+auto user_interface::draw_main_menu() -> void
+{
+    menu_grid.update_bounds(0, 0, GetScreenWidth(), MENU_HEIGHT);
+
+    draw_menu_header(GRAY);
+    draw_graph_info(ORANGE);
+    draw_graph_controls(RED);
+    draw_camera_controls(DARKGREEN);
+
+    if (input.editing) {
+        draw_edit_controls(PURPLE);
+    } else {
+        draw_puzzle_controls(BLUE);
+    }
+
+    draw_menu_footer(GRAY);
+}
+
+auto user_interface::draw_puzzle_board() -> void
+{
+    const puzzle& current = state.get_current_state();
+
+    board_grid.update_bounds(0, MENU_HEIGHT, GetScreenWidth() / 2, GetScreenHeight() - MENU_HEIGHT, current.get_width(),
+                             current.get_height());
+
+    // Draw outer border
+    const Rectangle bounds = board_grid.square_bounds();
+    DrawRectangleRec(bounds, current.goal_reached() ? BOARD_COLOR_WON : BOARD_COLOR_RESTRICTED);
+
+    // Draw inner borders
+    DrawRectangle(bounds.x + BOARD_PADDING, bounds.y + BOARD_PADDING, bounds.width - 2 * BOARD_PADDING,
+                  bounds.height - 2 * BOARD_PADDING,
+                  current.get_restricted() ? BOARD_COLOR_RESTRICTED : BOARD_COLOR_FREE);
+
+    // Draw target opening
+    // TODO: Only draw single direction (in corner) if restricted (use target block principal
+    // direction)
+    const std::optional<puzzle::block> target_block = current.try_get_target_block();
+    const int target_x = current.get_goal_x();
+    const int target_y = current.get_goal_y();
+    if (current.get_goal() && target_block) {
+        auto [x, y, width, height] = board_grid.square_bounds(target_x, target_y, target_block->get_width(),
+                                                              target_block->get_height());
+
+        const Color opening_color = Fade(current.goal_reached() ? BOARD_COLOR_WON : BOARD_COLOR_RESTRICTED, 0.3);
+
+        if (target_x == 0) {
+            // Left opening
+            DrawRectangle(x - BOARD_PADDING, y, BOARD_PADDING, height, RAYWHITE);
+            DrawRectangle(x - BOARD_PADDING, y, BOARD_PADDING, height, opening_color);
+        }
+        if (target_x + target_block->get_width() == current.get_width()) {
+            // Right opening
+            DrawRectangle(x + width, y, BOARD_PADDING, height, RAYWHITE);
+            DrawRectangle(x + width, y, BOARD_PADDING, height, opening_color);
+        }
+        if (target_y == 0) {
+            // Top opening
+            DrawRectangle(x, y - BOARD_PADDING, width, BOARD_PADDING, RAYWHITE);
+            DrawRectangle(x, y - BOARD_PADDING, width, BOARD_PADDING, opening_color);
+        }
+        if (target_y + target_block->get_height() == current.get_height()) {
+            // Bottom opening
+            DrawRectangle(x, y + height, width, BOARD_PADDING, RAYWHITE);
+            DrawRectangle(x, y + height, width, BOARD_PADDING, opening_color);
+        }
+    }
+
+    // Draw empty cells. Also set hovered blocks
+    input.hov_x = -1;
+    input.hov_y = -1;
+    for (int x = 0; x < board_grid.columns; ++x) {
+        for (int y = 0; y < board_grid.rows; ++y) {
+            DrawRectangleRec(board_grid.square_bounds(x, y, 1, 1), RAYWHITE);
+
+            Rectangle hov_bounds = board_grid.square_bounds(x, y, 1, 1);
+            hov_bounds.x -= BOARD_PADDING;
+            hov_bounds.y -= BOARD_PADDING;
+            hov_bounds.width += BOARD_PADDING;
+            hov_bounds.height += BOARD_PADDING;
+            if (CheckCollisionPointRec(GetMousePosition() - Vector2(0, MENU_HEIGHT), hov_bounds)) {
+                input.hov_x = x;
+                input.hov_y = y;
+            }
+        }
+    }
+
+    // Draw blocks
+    for (const puzzle::block b : current.block_view()) {
+        Color c = BLOCK_COLOR;
+        if (b.get_target()) {
+            c = TARGET_BLOCK_COLOR;
+        } else if (b.get_immovable()) {
+            c = WALL_COLOR;
+        }
+
+        const auto [x, y, w, h, t, i] = b.unpack_repr();
+
+        draw_board_block(x, y, w, h, c, !i);
+    }
+
+    // Draw block placing
+    if (input.editing && input.has_block_add_xy) {
+        if (current.covers(input.block_add_x, input.block_add_y) && input.hov_x >= input.block_add_x && input.hov_y >=
+            input.block_add_y) {
+            bool collides = false;
+            for (const puzzle::block b : current.block_view()) {
+                if (b.collides(puzzle::block(input.block_add_x, input.block_add_y, input.hov_x - input.block_add_x + 1,
+                                             input.hov_y - input.block_add_y + 1, false))) {
+                    collides = true;
+                    break;
+                }
+            }
+            if (!collides) {
+                draw_board_block(input.block_add_x, input.block_add_y, input.hov_x - input.block_add_x + 1,
+                                 input.hov_y - input.block_add_y + 1, PURPLE);
+            }
+        }
+    }
+
+    // TODO: In edit mode
+    //       - Clear Goal button doesn't work
+    //       - Toggle Target Block button throws "Grid bounds out of range"
+    //       - Clicking the goal to remove it throws "Grid bounds out of range"
+    // Draw goal boundaries when editing
+    if (input.editing && current.get_goal() && target_block) {
+        DrawRectangleLinesEx(
+            board_grid.square_bounds(target_x, target_y, target_block->get_width(), target_block->get_height()), 2.0,
+            TARGET_BLOCK_COLOR);
+    }
+}
+
+auto user_interface::draw_graph_overlay(int fps, int ups, size_t mass_count, size_t spring_count) -> void
+{
+    graph_overlay_grid.update_bounds(GetScreenWidth() / 2, MENU_HEIGHT);
+    debug_overlay_grid.update_bounds(GetScreenWidth() / 2, GetScreenHeight() - 75);
+
+    draw_label(graph_overlay_grid.bounds(0, 0, 1, 1), std::format("Dist: {:0>7.2f}", camera.distance), BLACK);
+    draw_label(graph_overlay_grid.bounds(0, 1, 1, 1), std::format("FoV:  {:0>6.2f}", camera.fov), BLACK);
+    draw_label(graph_overlay_grid.bounds(0, 2, 1, 1), std::format("FPS:  {:0>3}", fps), LIME);
+    draw_label(graph_overlay_grid.bounds(0, 3, 1, 1), std::format("UPS:  {:0>3}", ups), ORANGE);
+
+    // Debug
+    draw_label(debug_overlay_grid.bounds(0, 0, 1, 1), std::format("Physics Debug:"), BLACK);
+    draw_label(debug_overlay_grid.bounds(0, 1, 1, 1), std::format("Masses:  {}", mass_count), BLACK);
+    draw_label(debug_overlay_grid.bounds(0, 2, 1, 1), std::format("Springs: {}", spring_count), BLACK);
+}
+
+auto user_interface::draw(const int fps, const int ups, const size_t mass_count, const size_t spring_count) -> void
+{
+    const auto visitor = overloads{
+        [&](const show_ok_message& msg)
+        {
+            message_title = msg.title;
+            message_message = msg.message;
+            ok_message = true;
+        },
+        [&](const show_yes_no_message& msg)
+        {
+            message_title = msg.title;
+            message_message = msg.message;
+            yes_no_handler = msg.on_yes;
+            yes_no_message = true;
+        },
+        [&](const show_save_preset_window& msg)
+        {
+            save_window = true;
+        }
+    };
+
+    while (!input.ui_commands.empty()) {
+        const ui_command& cmd = input.ui_commands.front();
+
+        cmd.visit(visitor);
+
+        input.ui_commands.pop();
+    }
+
+    input.disable = window_open();
+
+    draw_graph_overlay(fps, ups, mass_count, spring_count);
+    draw_save_preset_popup();
+    draw_ok_message_box();
+    draw_yes_no_message_box();
+}

test/bits.cpp

@@ -0,0 +1,267 @@
+#include <catch2/catch_test_macros.hpp>
+#include <catch2/catch_template_test_macros.hpp>
+#include <cstdint>
+
+#include "util.hpp"
+
+// =============================================================================
+// Catch2
+// =============================================================================
+//
+// 1. TEST_CASE(name, tags)
+//    The basic unit of testing in Catch2. Each TEST_CASE is an independent test
+//    function. The first argument is a descriptive name (must be unique), and
+//    the second is a string of tags in square brackets (e.g. "[set_bits]")
+//    used to filter and group tests when running.
+//
+// 2. SECTION(name)
+//    Sections allow multiple subtests within a single TEST_CASE. Each SECTION
+//    runs the TEST_CASE from the top, so any setup code before the SECTION is
+//    re-executed fresh for every section. This gives each section an isolated
+//    starting state without needing separate TEST_CASEs or explicit teardown.
+//    Sections can also be nested.
+//
+// 3. REQUIRE(expression)
+//    The primary assertion macro. If the expression evaluates to false, the
+//    test fails immediately and Catch2 reports the actual values of both sides
+//    of the comparison (e.g. "0xF5 == 0xF0" on failure). There is also
+//    CHECK(), which records a failure but continues executing the rest of the
+//    test; REQUIRE() aborts the current test on failure.
+//
+// 4. TEMPLATE_TEST_CASE(name, tags, Type1, Type2, ...)
+//    A parameterised test that is instantiated once for each type listed.
+//    Inside the test body, the alias `TestType` refers to the current type.
+//    This avoids duplicating identical logic for uint8_t, uint16_t, uint32_t,
+//    and uint64_t. Catch2 automatically appends the type name to the test name
+//    in the output so you can see which instantiation failed.
+//
+// 5. Tags (e.g. "[create_mask]", "[round-trip]")
+//    Tags let you selectively run subsets of tests from the command line.
+//    For example:
+//      ./tests "[set_bits]"        -- runs only tests tagged [set_bits]
+//      ./tests "~[round-trip]"     -- runs everything except [round-trip]
+//      ./tests "[get_bits],[set_bits]" -- runs tests matching either tag
+//
+// =============================================================================
+
+// ---------------------------------------------------------------------------
+// create_mask
+// ---------------------------------------------------------------------------
+
+TEMPLATE_TEST_CASE("create_mask produces correct masks", "[create_mask]",
+                   uint8_t, uint16_t, uint32_t, uint64_t)
+{
+    SECTION("single bit mask at bit 0") {
+        auto m = create_mask<TestType>(0, 0);
+        REQUIRE(m == TestType{0b1});
+    }
+
+    SECTION("single bit mask at bit 3") {
+        auto m = create_mask<TestType>(3, 3);
+        REQUIRE(m == TestType{0b1000});
+    }
+
+    SECTION("mask spanning bits 0..7 gives 0xFF") {
+        auto m = create_mask<TestType>(0, 7);
+        REQUIRE(m == TestType{0xFF});
+    }
+
+    SECTION("mask spanning bits 4..7") {
+        auto m = create_mask<TestType>(4, 7);
+        REQUIRE(m == TestType{0xF0});
+    }
+
+    SECTION("full-width mask returns all ones") {
+        constexpr uint8_t last = sizeof(TestType) * 8 - 1;
+        auto m = create_mask<TestType>(0, last);
+        REQUIRE(m == static_cast<TestType>(~TestType{0}));
+    }
+}
+
+TEST_CASE("create_mask 32-bit specific cases", "[create_mask]") {
+    REQUIRE(create_mask<uint32_t>(0, 15)  == 0x0000FFFF);
+    REQUIRE(create_mask<uint32_t>(0, 31)  == 0xFFFFFFFF);
+    REQUIRE(create_mask<uint32_t>(16, 31) == 0xFFFF0000);
+}
+
+// ---------------------------------------------------------------------------
+// clear_bits
+// ---------------------------------------------------------------------------
+
+TEMPLATE_TEST_CASE("clear_bits zeroes the specified range", "[clear_bits]",
+                   uint8_t, uint16_t, uint32_t, uint64_t)
+{
+    SECTION("clear all bits") {
+        TestType val = static_cast<TestType>(~TestType{0});
+        constexpr uint8_t last = sizeof(TestType) * 8 - 1;
+        clear_bits(val, 0, last);
+        REQUIRE(val == TestType{0});
+    }
+
+    SECTION("clear lower nibble") {
+        TestType val = static_cast<TestType>(0xFF);
+        clear_bits(val, 0, 3);
+        REQUIRE(val == static_cast<TestType>(0xF0));
+    }
+
+    SECTION("clear upper nibble") {
+        TestType val = static_cast<TestType>(0xFF);
+        clear_bits(val, 4, 7);
+        REQUIRE(val == static_cast<TestType>(0x0F));
+    }
+
+    SECTION("clear single bit") {
+        TestType val = static_cast<TestType>(0xFF);
+        clear_bits(val, 0, 0);
+        REQUIRE(val == static_cast<TestType>(0xFE));
+    }
+
+    SECTION("clearing already-zero bits is a no-op") {
+        TestType val = TestType{0};
+        clear_bits(val, 0, 3);
+        REQUIRE(val == TestType{0});
+    }
+}
+
+// ---------------------------------------------------------------------------
+// set_bits
+// ---------------------------------------------------------------------------
+
+TEMPLATE_TEST_CASE("set_bits writes value into the specified range", "[set_bits]",
+                   uint8_t, uint16_t, uint32_t, uint64_t)
+{
+    SECTION("set lower nibble on zero") {
+        TestType val = TestType{0};
+        set_bits(val, uint8_t{0}, uint8_t{3}, static_cast<TestType>(0xA));
+        REQUIRE(val == static_cast<TestType>(0x0A));
+    }
+
+    SECTION("set upper nibble on zero") {
+        TestType val = TestType{0};
+        set_bits(val, uint8_t{4}, uint8_t{7}, static_cast<TestType>(0xB));
+        REQUIRE(val == static_cast<TestType>(0xB0));
+    }
+
+    SECTION("set_bits replaces existing bits") {
+        TestType val = static_cast<TestType>(0xFF);
+        set_bits(val, uint8_t{0}, uint8_t{3}, static_cast<TestType>(0x5));
+        REQUIRE(val == static_cast<TestType>(0xF5));
+    }
+
+    SECTION("set single bit to 1") {
+        TestType val = TestType{0};
+        set_bits(val, uint8_t{3}, uint8_t{3}, static_cast<TestType>(1));
+        REQUIRE(val == static_cast<TestType>(0x08));
+    }
+
+    SECTION("set single bit to 0") {
+        TestType val = static_cast<TestType>(0xFF);
+        set_bits(val, uint8_t{3}, uint8_t{3}, static_cast<TestType>(0));
+        REQUIRE(val == static_cast<TestType>(0xF7));
+    }
+
+    SECTION("setting value 0 clears the range") {
+        TestType val = static_cast<TestType>(0xFF);
+        set_bits(val, uint8_t{0}, uint8_t{7}, static_cast<TestType>(0));
+        REQUIRE(val == TestType{0});
+    }
+}
+
+TEST_CASE("set_bits with different value type (U != T)", "[set_bits]") {
+    uint32_t val = 0;
+    constexpr uint8_t small_val = 0x3F;
+    set_bits(val, uint8_t{8}, uint8_t{13}, small_val);
+    REQUIRE(val == (uint32_t{0x3F} << 8));
+}
+
+TEST_CASE("set_bits preserves surrounding bits in 32-bit", "[set_bits]") {
+    uint32_t val = 0xDEADBEEF;
+    set_bits(val, uint8_t{8}, uint8_t{15}, uint32_t{0x42});
+    REQUIRE(val == 0xDEAD42EF);
+}
+
+// ---------------------------------------------------------------------------
+// get_bits
+// ---------------------------------------------------------------------------
+
+TEMPLATE_TEST_CASE("get_bits extracts the specified range", "[get_bits]",
+                   uint8_t, uint16_t, uint32_t, uint64_t)
+{
+    SECTION("get lower nibble") {
+        TestType val = static_cast<TestType>(0xAB);
+        auto result = get_bits(val, uint8_t{0}, uint8_t{3});
+        REQUIRE(result == TestType{0xB});
+    }
+
+    SECTION("get upper nibble") {
+        TestType val = static_cast<TestType>(0xAB);
+        auto result = get_bits(val, uint8_t{4}, uint8_t{7});
+        REQUIRE(result == TestType{0xA});
+    }
+
+    SECTION("get single bit that is set") {
+        TestType val = static_cast<TestType>(0x08);
+        auto result = get_bits(val, uint8_t{3}, uint8_t{3});
+        REQUIRE(result == TestType{1});
+    }
+
+    SECTION("get single bit that is clear") {
+        TestType val = static_cast<TestType>(0xF7);
+        auto result = get_bits(val, uint8_t{3}, uint8_t{3});
+        REQUIRE(result == TestType{0});
+    }
+
+    SECTION("get all bits") {
+        TestType val = static_cast<TestType>(~TestType{0});
+        constexpr uint8_t last = sizeof(TestType) * 8 - 1;
+        auto result = get_bits(val, uint8_t{0}, last);
+        REQUIRE(result == val);
+    }
+
+    SECTION("get from zero returns zero") {
+        TestType val = TestType{0};
+        auto result = get_bits(val, uint8_t{0}, uint8_t{7});
+        REQUIRE(result == TestType{0});
+    }
+}
+
+TEST_CASE("get_bits 32-bit specific extractions", "[get_bits]") {
+    constexpr uint32_t val = 0xDEADBEEF;
+
+    REQUIRE(get_bits(val, uint8_t{0},  uint8_t{7})  == 0xEF);
+    REQUIRE(get_bits(val, uint8_t{8},  uint8_t{15}) == 0xBE);
+    REQUIRE(get_bits(val, uint8_t{16}, uint8_t{23}) == 0xAD);
+    REQUIRE(get_bits(val, uint8_t{24}, uint8_t{31}) == 0xDE);
+}
+
+// ---------------------------------------------------------------------------
+// Round-trip: set then get
+// ---------------------------------------------------------------------------
+
+TEST_CASE("set_bits then get_bits round-trips correctly", "[round-trip]") {
+    uint32_t reg = 0;
+
+    set_bits(reg, uint8_t{4}, uint8_t{11}, uint32_t{0xAB});
+    REQUIRE(get_bits(reg, uint8_t{4}, uint8_t{11}) == 0xAB);
+
+    REQUIRE(get_bits(reg, uint8_t{0},  uint8_t{3})  == 0x0);
+    REQUIRE(get_bits(reg, uint8_t{12}, uint8_t{31}) == 0x0);
+}
+
+TEST_CASE("multiple set_bits on different ranges", "[round-trip]") {
+    uint32_t reg = 0;
+
+    set_bits(reg, uint8_t{0},  uint8_t{7},  uint32_t{0x01});
+    set_bits(reg, uint8_t{8},  uint8_t{15}, uint32_t{0x02});
+    set_bits(reg, uint8_t{16}, uint8_t{23}, uint32_t{0x03});
+    set_bits(reg, uint8_t{24}, uint8_t{31}, uint32_t{0x04});
+
+    REQUIRE(reg == 0x04030201);
+}
+
+TEST_CASE("64-bit round-trip", "[round-trip]") {
+    uint64_t reg = 0;
+    set_bits(reg, uint8_t{32}, uint8_t{63}, uint64_t{0xCAFEBABE});
+    REQUIRE(get_bits(reg, uint8_t{32}, uint8_t{63}) == uint64_t{0xCAFEBABE});
+    REQUIRE(get_bits(reg, uint8_t{0},  uint8_t{31}) == uint64_t{0});
+}