Merge pull request #694 from got-feedback/perf/highway-frame-hotspots

perf: eliminate per-frame layout thrash, shader-compile spikes, and per-frame allocations in the player

CHANGELOG.md

@@ -7,6 +7,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+- **Player frame-time hotspots removed (trace-backed) + weak-hardware hardening.** A Chrome performance trace of a 3D-highway session surfaced two core per-frame layout-thrash sources, now fixed: the highway's visibility check read `canvas.offsetParent` every rAF frame (forces style/layout recalc — now sampled every 10th frame with a cached value, force-refreshed on init/canvas-replace/resize/override-clear), and the v3 player chrome loop called `matches(':hover')` per frame and unconditionally rewrote the Up-Next pill's `textContent`/bar width at 6 Hz (now hover-tracked via mouseenter/mouseleave, DOM writes only on value change, progress bar moved from `width` to compositor-only `scaleX`). The 3D highway pre-warms shader programs (`ren.compile`) and deterministic label textures at init — and chart-dependent chord/section label textures on first draw — so first-appearance shader-compile/texture-upload frame spikes move into the load spinner. For weaker hardware: the per-frame renderer bundle is now a single reused object instead of a fresh ~35-field allocation per frame (object identity is stable and meaningless; array fields still swap reference on chart changes), custom viz get `bundle.lowerBoundT`/`bundle.lowerBoundTime` binary-search helpers for visible-window culling, the default 2D highway's beat lines no longer scan every beat in the song per frame, and the 3D highway stops reading `localStorage` per frame (1 Hz poll) and caches its lyrics text-measurement layout per displayed line instead of re-measuring every syllable every frame. A second, throttled-CPU trace pass additionally removed: shader-program re-resolution churn from label texture swaps (`material.needsUpdate` is now only set on a null↔texture transition — swapping between two cached label textures never changes the compiled program), the 3D highway's per-frame `getBoundingClientRect` layout read in its canvas-size self-check (now every 10th frame, still immediate on backing-store change), and the core 60 Hz HUD clock rewriting `textContent` on every tick (now write-on-change, ~1/s). The dominant residual — steady `getParameters` shader-program re-resolution (~4% of throttled main thread) — turned out to be Three r158+'s transparent-DoubleSide two-pass rendering, which sets `material.needsUpdate` twice per object per frame; all 18 of the 3D highway's transparent DoubleSide materials are flat unlit quads (labels, rails, chord frames, lanes), so they now declare `forceSinglePass: true`, eliminating the recompile churn and halving those objects' draw calls.
+
 ### Added
 - **3D Drum Highway: hit FX — sparks, timing-colored lane flashes, kick camera pulse, approach glow, and open hi-hat notation (parity slice 2).** Striking a pad now *feels* struck: a pooled additive **spark burst** fires at the lane (ported from the guitar highway's Points-cloud system, pool 160), colored by **timing** — on-time green, early cyan, late amber (same `_timingHex` vocabulary as `highway_3d`, classified against the ±50 ms hit window with the inner 40% reading as on-time); with **Streak feedback** on, bursts grow with your combo. The **lane flash** feedback that was removed when note-recoloring landed is resurrected properly: pooled additive quads with a soft gaussian falloff light up the struck lane at the hit line (timing-colored; red for wrong-pad hits), and a **kick** hit fires triple amber bursts across the bar plus a subtle **camera dip + amber floor wash** that decays exponentially. Lanes also glow ahead of time: each stripe brightens as its next note approaches the hit line, so the eye is led to where the next hit lands. **Open hi-hat finally renders distinctly** — `hh_open` chart hits get a thin warm ring around the cymbal gem (standard notation's "o"), closing the long-standing TODO; the flag is orthogonal to accents/ghosts/flams so combined cues stack. All of it is settings-gated (Graphics → Hit sparks / Timing colours / Streak feedback / a 0–1 **Hit feedback intensity** slider driving flashes, approach glow and the kick pulse; everything on by default, `drum_h3d_bg_*` keys, live-applying) and GPU-frugal: every new visual is pooled or shares geometry/materials — zero per-note allocation on top of the per-frame notes rebuild, all registered in both dispose paths (kit-change renderer recreation included). Tests: timing-classifier boundaries + FX defaults added to `plugins/drum_highway_3d/tests/data_layer.test.js` (10 total).
 - **3D Drum Highway: bloom glow + adaptive-resolution support — the first slice of visual parity with the guitar highway.** The drum highway now renders through the same post-processing path as `highway_3d`: an `UnrealBloomPass` (strength 0.65, radius 0.5, threshold 0.82 — high, so only emissive/bright surfaces bleed) on a multisampled HalfFloat target with ACES filmic tone mapping, so the white hit-line bar and proximity-lit notes get a real glow instead of a flat emissive tint. **On by default**, with a new **Graphics → "Glow (bloom)"** toggle in the plugin settings (`drum_h3d_bg_bloom`, applies live, no reload); if the vendored postprocessing addons can't load (older self-hosted core), the plugin silently falls back to the direct render path. The plugin also now honors the host's **adaptive render scale** (`bundle.renderScale` — the Quality/"Min res" controls that the guitar highway already respected), multiplying it into the device pixel ratio, and caps DPR at 1.25 when more than one viz instance is live (splitscreen) so two panels don't double the GPU fill cost. Groundwork for the rest of the parity series: an FX-settings scaffold (`FX_DEFAULTS`/`readFxSettings`/`window.drumH3dSetFx`, `drum_h3d_bg_*` localStorage keys) that the sparks/themes/backgrounds PRs extend, plus a first node test suite for the plugin (`plugins/drum_highway_3d/tests/data_layer.test.js` — vm-loaded like the keys plugin's, covering the hit-variant precedence, the Auto-mode steal-guard predicate, and FX defaults; 8 tests, runs in CI via the `plugins/*/tests/*.test.js` glob).