Major improvements:
- NumPy-based collision system supporting 200+ units (~3ms/frame)
- Spatial hashing with vectorized distance calculations
- 4-pass game loop ensuring correct collision timing
- Blood overlay system with pre-generated stain pool
- Cached render positions and viewport bounds
- Spawn protection preventing rats spawning on weapons
Bug fixes:
- Fixed bombs not killing rats (collision system timing)
- Fixed gas not affecting rats (collision system timing)
- Fixed rats spawning on weapons (added has_weapon_at check)
- Fixed AttributeError with Gas collisions (added isinstance check)
- Fixed blood stain transparency (RGBA + SDL_BLENDMODE_BLEND)
- Reduced point lifetime from 200 to 90 frames (~1.5s)
- Blood layer now clears on game restart
Technical changes:
- Added engine/collision_system.py with CollisionLayer enum
- Updated all units to use collision layers
- Pre-allocate NumPy arrays with capacity management
- Hybrid collision approach (<10 simple, ≥10 vectorized)
- Python 3.13 compatibility
- Introduced a hybrid collision detection approach that utilizes NumPy for vectorized operations, improving performance for games with many entities (200+).
- Added a spatial grid for efficient lookups and AABB (Axis-Aligned Bounding Box) collision detection.
- Implemented a new `CollisionSystem` class with methods for registering units, checking collisions, and managing spatial data.
- Created performance tests to benchmark the new collision system against the old O(n²) method, demonstrating significant speed improvements.
- Updated existing code to integrate the new collision detection system and ensure compatibility with game logic.
Matteo Benedetto