run.sh:
- phase() wrapper logs elapsed seconds per build step.
- Tracks total build+startup at the end.
- Output is "==> phase / [Ns] phase" so the slow steps are obvious.
test/run.py:
- Per-step time.perf_counter() around each scenario step.
- "slowest steps" summary printed at the end so the worst
offenders are immediately visible.
- Total wall-clock time at scenario end.
src/render/mod.rs:
- browser_now() helper: web_sys::performance().now() on wasm,
Instant-based on native. Monotonic ms timestamps for tick/toc.
- Renderer::rebuild_chunk wraps build_chunk_mesh in a t0/t1
measurement and logs anything over 5ms with vertex/index counts.
Surfaces sky_visibility cost in the browser console.
web/main.js:
- Exposes window.voxel_game = wasm after init so the test
harness can drive scenarios declaratively (set_scene_time,
teleport, look_at, get_position, etc.).
src/shader.wgsl:
- Fix duplicate `let to_eye` declaration introduced in Round D
(specular's normalized to_eye conflicted with fog's raw version).
Renamed fog's local to_eye_raw. The test harness caught this
immediately — first WGSL compile error, first scenario run.
Findings from running scenarios/lighting-times-of-day.yaml:
- 289 chunks × ~100ms avg = ~29s mesh-build on main thread.
- Page-ready latency dominated by this. window.voxel_game appears
almost immediately (init resolves before chunks build), but
the world is invisible until meshes are uploaded.
- sky_visibility (8 cosine rays × HashMap voxel lookups) is the
hot path inside build_chunk_mesh.
Next: make chunk-mesh build progressive (one or two chunks per tick
instead of all up-front), so the world becomes visible immediately
and pops in over a few seconds.
