wip: integrating threaded decoupled physics

Current Issues:
- HUGE memory leak
- HUGE amount of needles copying
- FillGraph() does thousands of lock_guards instead of one
- Can no longer rely on new states appearing immediately - have to check
each access
- Physics run as fast as possible, no constant sim speed`
- Irregular long freezes

include/physics.hpp

@@ -7,6 +7,7 @@
 #include <raylib.h>
 #include <raymath.h>
 #include <thread>
+#include <tracy/Tracy.hpp>
 #include <unordered_map>
 #include <variant>
 #include <vector>
@@ -146,10 +147,10 @@ class ThreadedPhysics {
   using Command = std::variant<AddMass, AddSpring, ClearGraph>;
 
   struct PhysicsState {
-    std::mutex command_mtx;
+    TracyLockable(std::mutex, command_mtx);
     std::queue<Command> pending_commands;
 
-    std::mutex pos_mtx;
+    TracyLockable(std::mutex, pos_mtx);
     std::vector<Mass> masses;                    // Read by renderer
     std::unordered_map<State, int> state_masses; // Read by renderer
     std::vector<Spring> springs;                 // Read by renderer
@@ -160,9 +161,11 @@ class ThreadedPhysics {
   };
 
 private:
-  PhysicsState state;
   std::thread physics;
 
+public:
+  PhysicsState state;
+
 public:
   ThreadedPhysics() : physics(PhysicsThread, std::ref(state)) {}
 
@@ -180,6 +183,11 @@ private:
   static auto PhysicsThread(PhysicsState &state) -> void;
 
 public:
+  auto AddMassCmd(const State &_state) -> void;
+
+  auto AddSpringCmd(const State &a, const State &b) -> void;
+
+  auto ClearCmd() -> void;
 };
 
 // https://en.cppreference.com/w/cpp/utility/variant/visit

include/renderer.hpp

@@ -61,25 +61,29 @@ public:
   }
 
 private:
-  auto AllocateGraphInstancing(const MassSpringSystem &mass_springs) -> void;
+  auto AllocateGraphInstancing(const std::vector<Mass> &masses) -> void;
 
-  auto
+  auto ReallocateGraphInstancingIfNecessary(const std::vector<Mass> &masses)
-  ReallocateGraphInstancingIfNecessary(const MassSpringSystem &mass_springs)
       -> void;
 
 public:
   auto UpdateTextureSizes() -> void;
 
-  auto DrawMassSprings(const MassSpringSystem &mass_springs,
+  auto DrawMassSprings(
-                       const State &current_state, const State &starting_state,
+      const std::vector<Mass> &masses,
-                       const std::unordered_set<State> &winning_states,
+      const std::unordered_map<State, int> &state_masses,
-                       const std::unordered_set<State> &visited_states) -> void;
+      const std::vector<Spring> &springs,
+      const std::unordered_map<std::pair<State, State>, int> state_springs,
+      const State &current_state, const State &starting_state,
+      const std::unordered_set<State> &winning_states,
+      const std::unordered_set<State> &visited_states) -> void;
 
   auto DrawKlotski(const State &state, int hov_x, int hov_y, int sel_x,
                    int sel_y, int block_add_x, int block_add_y,
                    const WinCondition win_condition) -> void;
 
-  auto DrawMenu(const MassSpringSystem &mass_springs, int current_preset,
+  auto DrawMenu(const std::vector<Mass> &masses,
+                const std::vector<Spring> &springs, int current_preset,
                 const State &current_state,
                 const std::unordered_set<State> &winning_states) -> void;
 

include/state.hpp

@@ -1,7 +1,6 @@
 #ifndef __STATE_HPP_
 #define __STATE_HPP_
 
-#include "config.hpp"
 #include "physics.hpp"
 #include "presets.hpp"
 #include "puzzle.hpp"
@@ -10,7 +9,7 @@
 
 class StateManager {
 public:
-  MassSpringSystem &mass_springs;
+  ThreadedPhysics &physics;
 
   int current_preset;
   State starting_state;
@@ -23,12 +22,12 @@ public:
   std::unordered_set<State> visited_states;
 
 public:
-  StateManager(MassSpringSystem &_mass_springs)
+  StateManager(ThreadedPhysics &_physics)
-      : mass_springs(_mass_springs), current_preset(0),
+      : physics(_physics), current_preset(0),
         starting_state(generators[current_preset]()),
         current_state(starting_state), previous_state(starting_state),
         edited(false) {
-    mass_springs.AddMass(MASS, false, current_state);
+    physics.AddMassCmd(current_state);
   }
 
   StateManager(const StateManager &copy) = delete;

src/main.cpp

@@ -1,3 +1,4 @@
+#include <mutex>
 #include <raylib.h>
 #include <raymath.h>
 #include <tracy/Tracy.hpp>
@@ -37,20 +38,27 @@ auto main(int argc, char *argv[]) -> int {
   // Game setup
   OrbitCamera3D camera;
   Renderer renderer(camera);
-  MassSpringSystem mass_springs;
+  ThreadedPhysics physics;
-  StateManager state(mass_springs);
+  StateManager state(physics);
   InputHandler input(state, renderer);
 
+  std::vector<Mass> masses;                    // Read from physics
+  std::unordered_map<State, int> state_masses; // Read from physics
+  std::vector<Spring> springs;                 // Read from physics
+  std::unordered_map<std::pair<State, State>, int>
+      state_springs; // Read from physics
+
   // Game loop
-  double timestep_accumulator = 0.0;
+  // double timestep_accumulator = 0.0;
   while (!WindowShouldClose()) {
-    timestep_accumulator += GetFrameTime();
+    // timestep_accumulator += GetFrameTime();
 
     // Input update
     state.previous_state = state.current_state;
     input.HandleInput();
     state.UpdateGraph(); // Add state added after user input
 
+    /*
     // Physics update
     if (timestep_accumulator > TIMESTEP) {
       // Do not try to catch up if we're falling behind. Frametimes would get
@@ -63,21 +71,43 @@ auto main(int argc, char *argv[]) -> int {
 
       timestep_accumulator -= TIMESTEP;
     }
+    */
+
+    // Read positions from physics thread
+    // TODO: We're reading a HUGE amount of SHIT, because the state
+    //       representations (std::string, ~100 Bytes) are copied ~3 times per
+    //       spring: state_masses<State, int> and state_springs<<State, State>,
+    //       int>
+    // TODO: Don't download each frame if nothing changed, check for update
+    //       first
+    {
+      std::lock_guard<LockableBase(std::mutex)> lock(physics.state.pos_mtx);
+      masses = physics.state.masses;
+      state_masses = physics.state.state_masses;
+      springs = physics.state.springs;
+      state_springs = physics.state.state_springs;
+    }
 
     // Update the camera after the physics, so target lock is smooth
-    camera.Update(mass_springs.GetMass(state.current_state).position);
+    if (state_masses.contains(state.current_state)) {
+      const Mass &current_mass =
+          masses.at(state_masses.at(state.current_state));
+      camera.Update(current_mass.position);
+    }
 
     // Rendering
     renderer.UpdateTextureSizes();
-    renderer.DrawMassSprings(mass_springs, state.current_state,
+    if (masses.size() > 0 && state_masses.contains(state.current_state)) {
-                             state.starting_state, state.winning_states,
+      renderer.DrawMassSprings(masses, state_masses, springs, state_springs,
-                             state.visited_states);
+                               state.current_state, state.starting_state,
+                               state.winning_states, state.visited_states);
+    }
 
     renderer.DrawKlotski(state.current_state, input.hov_x, input.hov_y,
                          input.sel_x, input.sel_y, input.block_add_x,
                          input.block_add_y, state.CurrentWinCondition());
-    renderer.DrawMenu(mass_springs, state.current_preset, state.current_state,
+    renderer.DrawMenu(masses, springs, state.current_preset,
-                      state.winning_states);
+                      state.current_state, state.winning_states);
     renderer.DrawTextures();
   }
 

src/physics.cpp

@@ -344,15 +344,15 @@ auto ThreadedPhysics::PhysicsThread(ThreadedPhysics::PhysicsState &state)
   MassSpringSystem mass_springs;
 
   const auto visitor = overloads{
-      [&](const AddMass &am) { mass_springs.AddMass(am.s); },
+      [&](const struct AddMass &am) { mass_springs.AddMass(am.s); },
-      [&](const AddSpring &as) { mass_springs.AddSpring(as.a, as.b); },
+      [&](const struct AddSpring &as) { mass_springs.AddSpring(as.a, as.b); },
-      [&](const ClearGraph &cg) { mass_springs.Clear(); },
+      [&](const struct ClearGraph &cg) { mass_springs.Clear(); },
   };
 
   while (state.running) {
     // Handle queued commands
     {
-      std::lock_guard<std::mutex> lock(state.command_mtx);
+      std::lock_guard<LockableBase(std::mutex)> lock(state.command_mtx);
       while (!state.pending_commands.empty()) {
         Command &cmd = state.pending_commands.front();
         cmd.visit(visitor);
@@ -373,7 +373,7 @@ auto ThreadedPhysics::PhysicsThread(ThreadedPhysics::PhysicsState &state)
 
     // Publish the positions for the renderer (copy)
     {
-      std::lock_guard<std::mutex> lock(state.pos_mtx);
+      std::lock_guard<LockableBase(std::mutex)> lock(state.pos_mtx);
       state.masses = mass_springs.masses;
       state.state_masses = mass_springs.state_masses;
       state.springs = mass_springs.springs;
@@ -381,3 +381,24 @@ auto ThreadedPhysics::PhysicsThread(ThreadedPhysics::PhysicsState &state)
     }
   }
 }
+
+auto ThreadedPhysics::AddMassCmd(const State &_state) -> void {
+  {
+    std::lock_guard<LockableBase(std::mutex)> lock(state.command_mtx);
+    state.pending_commands.push(AddMass{_state});
+  }
+}
+
+auto ThreadedPhysics::AddSpringCmd(const State &a, const State &b) -> void {
+  {
+    std::lock_guard<LockableBase(std::mutex)> lock(state.command_mtx);
+    state.pending_commands.push(AddSpring{a, b});
+  }
+}
+
+auto ThreadedPhysics::ClearCmd() -> void {
+  {
+    std::lock_guard<LockableBase(std::mutex)> lock(state.command_mtx);
+    state.pending_commands.push(ClearGraph{});
+  }
+}

src/renderer.cpp

@@ -33,7 +33,7 @@ auto Renderer::UpdateTextureSizes() -> void {
   menu_target = LoadRenderTexture(width * 2, MENU_HEIGHT);
 }
 
-auto Renderer::AllocateGraphInstancing(const MassSpringSystem &mass_springs)
+auto Renderer::AllocateGraphInstancing(const std::vector<Mass> &masses)
     -> void {
   cube_instance = GenMeshCube(VERTEX_SIZE, VERTEX_SIZE, VERTEX_SIZE);
 
@@ -48,38 +48,40 @@ auto Renderer::AllocateGraphInstancing(const MassSpringSystem &mass_springs)
   vertex_mat.maps[MATERIAL_MAP_DIFFUSE].color = VERTEX_COLOR;
   vertex_mat.shader = instancing_shader;
 
-  transforms = (Matrix *)MemAlloc(mass_springs.masses.size() * sizeof(Matrix));
+  transforms = (Matrix *)MemAlloc(masses.size() * sizeof(Matrix));
-  transforms_size = mass_springs.masses.size();
+  transforms_size = masses.size();
 }
 
 auto Renderer::ReallocateGraphInstancingIfNecessary(
-    const MassSpringSystem &mass_springs) -> void {
+    const std::vector<Mass> &masses) -> void {
-  if (transforms_size != mass_springs.masses.size()) {
+  if (transforms_size != masses.size()) {
-    transforms = (Matrix *)MemRealloc(transforms, mass_springs.masses.size() *
+    transforms =
-                                                      sizeof(Matrix));
+        (Matrix *)MemRealloc(transforms, masses.size() * sizeof(Matrix));
-    transforms_size = mass_springs.masses.size();
+    transforms_size = masses.size();
   }
 }
 
-auto Renderer::DrawMassSprings(const MassSpringSystem &mass_springs,
+auto Renderer::DrawMassSprings(
-                               const State &current_state,
+    const std::vector<Mass> &masses,
-                               const State &starting_state,
+    const std::unordered_map<State, int> &state_masses,
-                               const std::unordered_set<State> &winning_states,
+    const std::vector<Spring> &springs,
-                               const std::unordered_set<State> &visited_states)
+    const std::unordered_map<std::pair<State, State>, int> state_springs,
-    -> void {
+    const State &current_state, const State &starting_state,
+    const std::unordered_set<State> &winning_states,
+    const std::unordered_set<State> &visited_states) -> void {
   ZoneScoped;
 
   // Prepare cube instancing
   {
     ZoneNamedN(prepare_masses, "PrepareMasses", true);
-    if (mass_springs.masses.size() < DRAW_VERTICES_LIMIT) {
+    if (masses.size() < DRAW_VERTICES_LIMIT) {
       if (transforms == nullptr) {
-        AllocateGraphInstancing(mass_springs);
+        AllocateGraphInstancing(masses);
       }
-      ReallocateGraphInstancingIfNecessary(mass_springs);
+      ReallocateGraphInstancingIfNecessary(masses);
 
       int i = 0;
-      for (const auto &mass : mass_springs.masses) {
+      for (const auto &mass : masses) {
         transforms[i] =
             MatrixTranslate(mass.position.x, mass.position.y, mass.position.z);
         ++i;
@@ -96,10 +98,10 @@ auto Renderer::DrawMassSprings(const MassSpringSystem &mass_springs,
   {
     ZoneNamedN(draw_springs, "DrawSprings", true);
     rlBegin(RL_LINES);
-    for (const auto &spring : mass_springs.springs) {
+    for (const auto &spring : springs) {
       // We have to do a lookup of the actual mass object, which is slow :(
-      const Mass &a = mass_springs.masses.at(spring.mass_a);
+      const Mass &a = masses.at(spring.mass_a);
-      const Mass &b = mass_springs.masses.at(spring.mass_b);
+      const Mass &b = masses.at(spring.mass_b);
       rlColor4ub(EDGE_COLOR.r, EDGE_COLOR.g, EDGE_COLOR.b, EDGE_COLOR.a);
       rlVertex3f(a.position.x, a.position.y, a.position.z);
       rlVertex3f(b.position.x, b.position.y, b.position.z);
@@ -110,20 +112,19 @@ auto Renderer::DrawMassSprings(const MassSpringSystem &mass_springs,
   // Draw masses (instanced)
   {
     ZoneNamedN(draw_masses, "DrawMasses", true);
-    if (mass_springs.masses.size() < DRAW_VERTICES_LIMIT) {
+    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,
+      DrawMeshInstanced(cube_instance, vertex_mat, transforms, masses.size());
-                        mass_springs.masses.size());
     }
   }
 
   // Mark winning states
   if (mark_solutions || connect_solutions) {
     for (const auto &state : winning_states) {
-      const Mass &winning_mass = mass_springs.GetMass(state);
+      const Mass &winning_mass = masses.at(state_masses.at(state));
       if (mark_solutions) {
         DrawCube(winning_mass.position, 2 * VERTEX_SIZE, 2 * VERTEX_SIZE,
                  2 * VERTEX_SIZE, BLUE);
@@ -131,26 +132,26 @@ auto Renderer::DrawMassSprings(const MassSpringSystem &mass_springs,
 
       if (connect_solutions) {
         DrawLine3D(winning_mass.position,
-                   mass_springs.GetMass(current_state).position, PURPLE);
+                   masses.at(state_masses.at(current_state)).position, PURPLE);
       }
     }
   }
 
   // Mark visited states
   for (const auto &state : visited_states) {
-    const Mass &visited_mass = mass_springs.GetMass(state);
+    const Mass &visited_mass = masses.at(state_masses.at(state));
 
     DrawCube(visited_mass.position, VERTEX_SIZE * 1.5, VERTEX_SIZE * 1.5,
              VERTEX_SIZE * 1.5, PURPLE);
   }
 
   // Mark starting state
-  const Mass &starting_mass = mass_springs.GetMass(starting_state);
+  const Mass &starting_mass = masses.at(state_masses.at(starting_state));
   DrawCube(starting_mass.position, VERTEX_SIZE * 2, VERTEX_SIZE * 2,
            VERTEX_SIZE * 2, ORANGE);
 
   // Mark current state
-  const Mass &current_mass = mass_springs.GetMass(current_state);
+  const Mass &current_mass = masses.at(state_masses.at(current_state));
   DrawCube(current_mass.position, VERTEX_SIZE * 2, VERTEX_SIZE * 2,
            VERTEX_SIZE * 2, RED);
 
@@ -250,8 +251,9 @@ auto Renderer::DrawKlotski(const State &state, int hov_x, int hov_y, int sel_x,
   EndTextureMode();
 }
 
-auto Renderer::DrawMenu(const MassSpringSystem &mass_springs,
+auto Renderer::DrawMenu(const std::vector<Mass> &masses,
-                        int current_preset, const State &current_state,
+                        const std::vector<Spring> &springs, int current_preset,
+                        const State &current_state,
                         const std::unordered_set<State> &winning_states)
     -> void {
   ZoneScoped;
@@ -277,8 +279,7 @@ auto Renderer::DrawMenu(const MassSpringSystem &mass_springs,
 
   draw_btn(0, 0,
            std::format("States: {}, Transitions: {}, Winning: {}",
-                       mass_springs.masses.size(), mass_springs.springs.size(),
+                       masses.size(), springs.size(), winning_states.size()),
-                       winning_states.size()),
            DARKGREEN);
   draw_btn(
       0, 1,

src/state.cpp

@@ -1,8 +1,8 @@
 #include "state.hpp"
-#include "config.hpp"
 #include "presets.hpp"
 #include "tracy.hpp"
 
+#include <mutex>
 #include <raymath.h>
 
 auto StateManager::LoadPreset(int preset) -> void {
@@ -38,30 +38,18 @@ auto StateManager::FillGraph() -> void {
   std::pair<std::unordered_set<State>, std::vector<std::pair<State, State>>>
       closure = current_state.Closure();
   for (const auto &state : closure.first) {
-    mass_springs.AddMass(MASS, false, state);
+    physics.AddMassCmd(state);
   }
   for (const auto &[from, to] : closure.second) {
-    mass_springs.AddSpring(from, to, SPRING_CONSTANT, DAMPENING_CONSTANT,
+    physics.AddSpringCmd(from, to);
-                           REST_LENGTH);
   }
-  std::cout << "Inserted " << mass_springs.masses.size() << " masses and "
-            << mass_springs.springs.size() << " springs." << std::endl;
   FindWinningStates();
-  std::cout << "Consuming "
-            << sizeof(decltype(*mass_springs.masses.begin())) *
-                   mass_springs.masses.size()
-            << " Bytes for masses." << std::endl;
-  std::cout << "Consuming "
-            << sizeof(decltype(*mass_springs.springs.begin())) *
-                   mass_springs.springs.size()
-            << " Bytes for springs." << std::endl;
 }
 
 auto StateManager::UpdateGraph() -> void {
   if (previous_state != current_state) {
-    mass_springs.AddMass(MASS, false, current_state);
+    physics.AddMassCmd(current_state);
-    mass_springs.AddSpring(current_state, previous_state, SPRING_CONSTANT,
+    physics.AddSpringCmd(current_state, previous_state);
-                           DAMPENING_CONSTANT, REST_LENGTH);
     if (win_conditions[current_preset](current_state)) {
       winning_states.insert(current_state);
     }
@@ -72,8 +60,8 @@ auto StateManager::UpdateGraph() -> void {
 auto StateManager::ClearGraph() -> void {
   winning_states.clear();
   visited_states.clear();
-  mass_springs.Clear();
+  physics.ClearCmd();
-  mass_springs.AddMass(MASS, false, current_state);
+  physics.AddMassCmd(current_state);
 
   // The previous_state is no longer in the graph
   previous_state = current_state;
@@ -84,14 +72,16 @@ auto StateManager::ClearGraph() -> void {
 
 auto StateManager::FindWinningStates() -> void {
   winning_states.clear();
-  for (const auto &[state, mass] : mass_springs.state_masses) {
+  std::unordered_map<State, int> state_masses;
+  {
+    std::lock_guard<LockableBase(std::mutex)> lock(physics.state.pos_mtx);
+    state_masses = physics.state.state_masses;
+  }
+  for (const auto &[state, mass] : state_masses) {
     if (win_conditions[current_preset](state)) {
       winning_states.insert(state);
     }
   }
-
-  std::cout << "Found " << winning_states.size() << " winning states."
-            << std::endl;
 }
 
 auto StateManager::CurrentGenerator() -> StateGenerator {