2.3 KiB
2.3 KiB
lofivor - build roadmap
survivor-like optimized for weak hardware. finding the performance ceiling first, then building the game.
phase 1: sandbox stress test
- create sandbox.zig (separate from existing game code)
- entity struct (x, y, vx, vy, color)
- flat array storage for entities
- spawn entities at random screen edges
- update loop: move toward center, respawn on arrival
- render: filled circles (4px radius, cyan)
- metrics overlay (entity count, frame time, update time, render time)
- controls: +/- 100, shift +/- 1000, space pause, r reset
phase 2: find the ceiling
- test on i5-6500T / HD 530 @ 1280x1024
- record entity count where 60fps breaks
- identify bottleneck (CPU update vs GPU render)
- document findings
findings (AMD Radeon test):
- 60fps breaks at ~5000 entities
- render-bound: update stays <1ms even at 30k entities, render time dominates
- individual drawCircle calls are the bottleneck
phase 3: optimization experiments
based on phase 2 results:
- batch rendering via texture blitting (10x improvement)
- rlgl quad batching (2x improvement on top)
if cpu-bound: SIMD, struct-of-arrays, multithreading(not needed)- re-test after each change
findings:
- texture blitting: pre-render circle to texture, drawTexture() per entity
- rlgl batching: submit vertices directly via rl.gl, bypass drawTexture overhead
- baseline: 60fps @ ~5k entities
- after texture blitting: 60fps @ ~50k entities
- after rlgl batching: 60fps @ ~100k entities
- total: ~20x improvement from baseline
- see journal.txt for detailed benchmarks
further options (if needed):
- increase raylib batch buffer (currently 8192 vertices = 2048 quads per flush)
- GPU instancing (single draw call for all entities)
- or just move on - 100k @ 60fps is a solid ceiling
phase 4: add collision
- spatial partitioning (grid or quadtree)
- projectile-to-enemy collision
- measure new ceiling with collision enabled
phase 5: game loop
- player entity (keyboard controlled)
- enemy spawning waves
- player attacks / projectiles
- enemy death on hit
- basic game feel
future
- different enemy types
- player upgrades
- actual game design (after we know the constraints)