From 6698ace0c646fedcdda1a222272e601fded3f1df Mon Sep 17 00:00:00 2001
From: Christoph Urlacher <christoph.urlacher@protonmail.com>
Date: Mon, 23 Feb 2026 14:27:56 +0100
Subject: [PATCH] implement smooth camera

---
 include/camera.hpp | 14 +++++++++++---
 include/config.hpp |  3 ++-
 src/camera.cpp     | 45 +++++++++++++++++++++++++++++++--------------
 src/main.cpp       |  1 -
 4 files changed, 44 insertions(+), 19 deletions(-)

diff --git a/include/camera.hpp b/include/camera.hpp
index 2c3666b..cc9e31a 100644
--- a/include/camera.hpp
+++ b/include/camera.hpp
@@ -11,19 +11,25 @@ class OrbitCamera3D {
 
 private:
   Camera camera;
+
+  Vector3 position;
   Vector3 target;
+  Vector3 target_target;
   float distance;
   float angle_x;
   float angle_y;
+
+  // Input
   Vector2 last_mouse;
-  bool dragging;
+  bool rotating;
   bool panning;
   bool target_lock;
 
 public:
   OrbitCamera3D()
-      : camera({0}), target(Vector3Zero()), distance(CAMERA_DISTANCE),
-        angle_x(0.0), angle_y(0.0), last_mouse(Vector2Zero()), dragging(false),
+      : camera({0}), position(Vector3Zero()), target(Vector3Zero()),
+        target_target(Vector3Zero()), distance(CAMERA_DISTANCE), angle_x(0.0),
+        angle_y(0.0), last_mouse(Vector2Zero()), rotating(false),
         panning(false), target_lock(true) {
     camera.position = Vector3(0, 0, -1.0 * distance);
     camera.target = target;
@@ -35,6 +41,8 @@ public:
   ~OrbitCamera3D() {}
 
 public:
+  auto HandleCameraInput() -> Vector2;
+
   auto Update(const Vector3 &current_target) -> void;
 };
 
diff --git a/include/config.hpp b/include/config.hpp
index 46c4f6d..3f999eb 100644
--- a/include/config.hpp
+++ b/include/config.hpp
@@ -28,6 +28,7 @@ constexpr float ZOOM_MULTIPLIER = 4.0;
 constexpr float PAN_SPEED = 2.0;
 constexpr float PAN_MULTIPLIER = 10.0;
 constexpr float ROT_SPEED = 1.0;
+constexpr float CAMERA_SMOOTH_SPEED = 15.0;
 
 // Physics Engine
 constexpr float SIM_SPEED = 4.0;          // How large each update should be
@@ -38,7 +39,7 @@ constexpr float DAMPENING_CONSTANT = 1.0; // Mass spring system
 constexpr float REST_LENGTH = 2.0;        // Mass spring system
 constexpr float VERLET_DAMPENING = 0.05;  // [0, 1]
 constexpr float BH_FORCE = 2.0;           // BH: [1.0, 3.0]
-constexpr float THETA = 1.0;              // Barnes-Hut [0.5, ~]
+constexpr float THETA = 1.0;              // Barnes-Hut [0.5, 1.0]
 constexpr float SOFTENING = 0.01;         // Barnes-Hut [0.01, 1.0]
 constexpr float GRID_FORCE = 0.02;        // Grid: [0.0, ~0.05]
 constexpr float REPULSION_RANGE = 5.0 * REST_LENGTH; // Grid
diff --git a/src/camera.cpp b/src/camera.cpp
index c0673f2..b4629d9 100644
--- a/src/camera.cpp
+++ b/src/camera.cpp
@@ -1,20 +1,34 @@
 #include "camera.hpp"
+#include "config.hpp"
+#include "util.hpp"
 
-auto OrbitCamera3D::Update(const Vector3 &current_target) -> void {
+#include <iostream>
+#include <raylib.h>
+#include <raymath.h>
+
+auto OrbitCamera3D::HandleCameraInput() -> Vector2 {
   Vector2 mouse = GetMousePosition();
   if (mouse.x >= GetScreenWidth() / 2.0 && mouse.y >= MENU_HEIGHT) {
     if (IsMouseButtonPressed(MOUSE_RIGHT_BUTTON)) {
-      dragging = true;
+      rotating = true;
       last_mouse = mouse;
     } else if (IsMouseButtonPressed(MOUSE_LEFT_BUTTON)) {
       panning = true;
       target_lock = false;
       last_mouse = mouse;
     }
+
+    // Zoom
+    float wheel = GetMouseWheelMove();
+    if (IsKeyDown(KEY_LEFT_SHIFT)) {
+      distance -= wheel * ZOOM_SPEED * ZOOM_MULTIPLIER;
+    } else {
+      distance -= wheel * ZOOM_SPEED;
+    }
   }
 
   if (IsMouseButtonReleased(MOUSE_RIGHT_BUTTON)) {
-    dragging = false;
+    rotating = false;
   }
   if (IsMouseButtonReleased(MOUSE_LEFT_BUTTON)) {
     panning = false;
@@ -23,8 +37,13 @@ auto OrbitCamera3D::Update(const Vector3 &current_target) -> void {
   if (IsKeyPressed(KEY_L)) {
     target_lock = !target_lock;
   }
+  return mouse;
+}
 
-  if (dragging) {
+auto OrbitCamera3D::Update(const Vector3 &current_target) -> void {
+  Vector2 mouse = HandleCameraInput();
+
+  if (rotating) {
     Vector2 dx = Vector2Subtract(mouse, last_mouse);
     last_mouse = mouse;
 
@@ -38,13 +57,15 @@ auto OrbitCamera3D::Update(const Vector3 &current_target) -> void {
     Vector2 dx = Vector2Subtract(mouse, last_mouse);
     last_mouse = mouse;
 
-    // float speed = PAN_SPEED;
     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));
@@ -57,17 +78,13 @@ auto OrbitCamera3D::Update(const Vector3 &current_target) -> void {
   }
 
   if (target_lock) {
-    target = current_target;
+    target_target = current_target;
+    target = Vector3MoveTowards(
+        target, target_target,
+        CAMERA_SMOOTH_SPEED * GetFrameTime() *
+            Vector3Length(Vector3Subtract(target, target_target)));
   }
 
-  if (mouse.x >= GetScreenWidth() / 2.0 && mouse.y >= MENU_HEIGHT) {
-    float wheel = GetMouseWheelMove();
-    if (IsKeyDown(KEY_LEFT_SHIFT)) {
-      distance -= wheel * ZOOM_SPEED * ZOOM_MULTIPLIER;
-    } else {
-      distance -= wheel * ZOOM_SPEED;
-    }
-  }
   distance = Clamp(distance, MIN_CAMERA_DISTANCE, MAX_CAMERA_DISTANCE);
 
   // Spherical coordinates
diff --git a/src/main.cpp b/src/main.cpp
index 9b6cfbe..2a4794a 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -23,7 +23,6 @@
 //       - Click states to display them in the board
 //       - Find shortest path to any winning state and mark it in the graph
 //         - Also mark the next move along the path on the board
-// TODO: Smooth camera (on target change)
 // TODO: Mark the starting state
 // TODO: Mark the visited states