SCENEGOD/logs/laneB.md

Lane B log — append-only, newest at bottom

Format per session:

## <date> session N
DONE: …
DECISIONS: …
BLOCKED/REQUESTS: …
NEXT: …

2026-07-18 session 1

DONE: M1 complete. All files under scenegod/web/.

• timeline.js — model + clock, no DOM, no three import (self-contained quat/euler/slerp math so node can run it). load/toJSON lossless round-trip (unknown entity fields preserved via structuredClone + a WeakMap for cached quats). evaluate(t): transform (pos/scale lerp, rot slerp→euler, easing incl. step-hold), params (num lerp, color sRGB lerp), clip blocks (set-time exact scrubbing, fade-out ramp), camera cuts (fires only on change). Clock: play() rAF deltas, seek clamp, step(frame) pure/deterministic for Lane C render. Mutators addKey/moveKey/deleteKey/ addClipBlock/moveClipBlock/trimClipBlock/addCut + undo stack (undo() wired; Ctrl+Z hooked in tlui). capturekey window listener present. Clips need await tl.preload() before evaluate (prepareClip is async).
• tlui.js — canvas panel into #timeline. Ruler scrub, drag playhead, space=play/pause, dblclick lane=add key from stage state, drag key (snap to frame, Alt=free), right-click=delete, drag clip block/edge, Home/End, Ctrl+Z. Scene bar name/dur + Save/Load (POST/GET /scenes/{name}, localStorage fallback). Names column auto-syncs to stage.entities() via onChange.
• stagestub.js — full §4.2 Stage as plain objects; records effects into stage.applied[]. Dev-only, delete at SYNC 1.
• timeline_test.mjs — node scenegod/web/timeline_test.mjs → green (midpoint interp, step-ease hold, clip local time @3 frames, camera flip, lossless round-trip, unknown-field preservation).
• tldev.html — dev-only browser harness. Verified in browser: scrub moves entities (interp live in log), play runs to duration + auto-stops, camera cut flips camA→camB at t=3, keys/clips/cuts render. Delete at SYNC 1. DECISIONS:
• Timeline imports NO three.js — inlined euler↔quat + slerp (~30 lines) so the node self-check needs zero deps (there is no node_modules/three in this stack). setTransform rot is euler (matches entityTransform format).
• One <canvas> for all lanes (not canvas-per-lane); hit-testing via a hitbox list rebuilt each draw. Simpler, fast enough at this scale.
• CSS injected from tlui.js via a <style id=laneB-tl-css> rather than creating web/style.css — that file is Lane A's and didn't exist yet. Move into a /* === LANE B === */ block at SYNC if John wants it centralized. (See REQUEST below.)
• M1 crossfade = fade-OUT only; cross-block fade-IN is M2 "crossfade polish" per the milestone list. Marked with a ponytail comment in timeline.js. BLOCKED/REQUESTS:
• None blocking. Note for orchestrator/Lane A: my timeline styles live in an injected <style> in tlui.js. If you'd rather they sit in style.css, say so and I'll emit a /* === LANE B === */ block for Lane A to paste (I won't edit style.css directly — ownership).
• Lane A's files (index.html, stage.js, room3d.js, dock.js, style.css) are present untracked in the shared working dir but uncommitted — I staged ONLY my 5 files, left theirs alone. NEXT: Hold at M1 boundary. At SYNC 1 the stub swaps for the real Stage (one-line change in the page import) and tldev.html/stagestub.js get deleted. M2 (locked): clip crossfade polish, params/cut lane UI, snapping config, undo Ctrl+Z already stubbed, box-select multi-drag.