Updated game structure

src/graphics/Starfield3D.h

@@ -0,0 +1,63 @@
+// Starfield3D.h - 3D Parallax Starfield Effect (canonical)
+#pragma once
+
+#include <SDL3/SDL.h>
+#include <vector>
+#include <random>
+#include <array>
+
+class Starfield3D {
+public:
+    Starfield3D();
+    ~Starfield3D() = default;
+
+    void init(int width, int height, int starCount = 160);
+    void update(float deltaTime);
+    void draw(SDL_Renderer* renderer);
+    void resize(int width, int height);
+
+private:
+    struct Star3D {
+        float x, y, z;
+        float vx, vy, vz;
+        float targetVx, targetVy, targetVz;
+        float changeTimer;
+        bool changing;
+        int type;
+    };
+
+    // Helpers used by the implementation
+    void createStarfield();
+    void updateStar(int index);
+    void setRandomDirection(Star3D& star);
+    float randomFloat(float min, float max);
+    int randomRange(int min, int max);
+    void drawStar(SDL_Renderer* renderer, float x, float y, int type);
+
+    std::vector<Star3D> stars;
+    int width{0}, height{0};
+    float centerX{0}, centerY{0};
+
+    // Random number generator
+    std::mt19937 rng;
+
+    // Visual / behavioral constants (tweakable)
+    inline static constexpr float MAX_VELOCITY = 0.5f;
+    inline static constexpr float REVERSE_PROBABILITY = 0.12f;
+    inline static constexpr float STAR_SPEED = 0.6f;
+    inline static constexpr float MAX_DEPTH = 120.0f;
+    inline static constexpr float DIRECTION_CHANGE_PROBABILITY = 0.002f;
+    inline static constexpr float VELOCITY_CHANGE = 0.02f;
+    inline static constexpr float MIN_Z = 0.1f;
+    inline static constexpr float MAX_Z = MAX_DEPTH;
+    inline static constexpr float DEPTH_FACTOR = 320.0f;
+
+    inline static constexpr int COLOR_COUNT = 5;
+    inline static const std::array<SDL_Color, COLOR_COUNT> STAR_COLORS = {
+        SDL_Color{255,255,255,255},
+        SDL_Color{200,200,255,255},
+        SDL_Color{255,220,180,255},
+        SDL_Color{180,220,255,255},
+        SDL_Color{255,180,200,255}
+    };
+};