TURNCRAFT/docs/LANE_C_update.md

Lane C — World Builder · Progress Update

For Fable's review. Lane C = the level-design lane: author the entire DJ-booth diorama in voxels via buildBooth(world).

Status: ✅ complete and verified. Typecheck clean, demo renders with no console errors, build deterministic and fully validated. Ready for Lane D to mount machines.

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1. What shipped

file	role
src/worldgen/tools.ts	voxel toolkit: box, hollowBox, cylinderY, sphere, line3, spline (Catmull-Rom), mulberry32 PRNG, bounds-guarded setVox, duck-typed fillBox fast path
src/worldgen/anchors.ts	single source of truth for every LAYOUT-derived position (deck furniture, mixer face, patch-bay grid, under-table) — so no coordinate is written twice
src/worldgen/questPositions.ts	QUEST_POS — the Lane C→D contract: exact voxels for stylus/rca/crossfader/fuse/power
src/worldgen/buildBooth.ts	the build: buildShell, buildDeckA/B, buildMixer, buildCableCanyon, buildPatchBay, buildUnderTable, set-dressing; exports SPAWN
src/worldgen/index.ts	public barrel for integrators
src/demo/worldgenDemo.ts + demo-worldgen.html	standalone InstancedMesh visualizer, zone teleports, live validation panel
src/worldgen/HANDOFF.md	API surface + integration notes

2. What the booth contains (DESIGN §4, all present + eyeballed)

• Shell: warm plywood console, ply_edge laminate caps, front lip, hinge plates, tabletop with vent shafts behind each deck + a front-left crate hatch & stair.
• Deck A / Deck B: steel-grey plinths, rubber feet, brushed-alu top border, a recessed empty platter well with chrome spindle stub, start/stop + 33/45 button recesses, pitch-fader canyon with green centre-detent, tonearm base pedestal + empty headshell socket, Technics strobe lamp. Deck B adds dust drifts + a half-open glass dust cover.
• Mixer Massif: matte-black body, speaker-mesh climb vents, 4 channel strips (silver/black knob-stem grids + empty fader alleys), the crossfader tram with the dust-jam plug, two VU-meter towers (green→amber→red), power-switch recess, fuse chimney.
• Cable Canyon: 5 splined RCA/power cables draping to the patch bay, gold plug heads, a power strip, and the quest cable ending short with a loose gold plug on the floor.
• Patch Bay: proud alu panel, 2×6 gold socket grid, the conspicuously empty quest socket (red blink), two sockets that are real doorways into copper-busbar rooms.
• PCB Depths: green board floors, copper trace paths, capacitor pillars, solder stalagmites, sparse LEDs, the fuse box (blown fuse), the parts bin (fresh-fuse + the blue-spotlit stylus block), and the record crate of blue/black vinyl slabs on edge.

3. Verification (headless + in-demo + cross-lane, all green)

✓ build < 500ms (14ms mock / 30.7ms real VoxelWorld)
✓ deterministic — two runs byte-identical (seed 1210)
✓ 0 out-of-bounds writes
✓ deck A + deck B platter wells empty (left for Lane D's platter)
✓ spawn stands on solid steel with headroom, facing the mixer
✓ 8/8 quest anchor points reachable (adjacent air)
✓ fuse & stylus anchors land on the intended block (not a neighbour)
✓ record crate populated (regression-guarded)
  ~4.5M non-air voxels · 24.6% fill · 29/30 non-air block types used

Screenshotted the spawn deck, whole booth, PCB Depths, and the record crate — all read clearly as the intended DJ-booth diorama.

Adversarial review pass. I ran a 5-dimension multi-agent review (12 agents, each finding independently verified). It CONFIRMED 5 defects my first-pass validation missed — all now fixed and re-verified:

• [HIGH] the record crate placed zero records (footprint had collapsed to ~2 voxels) → re-anchored, now a full row of blue/black vinyl on edge.
• [MED] QUEST_POS.fuse.box sat on the frame, one voxel off the fuse → now exact.
• [MED] VU-tower LEDs were sealed inside a closed casing → front face opened.
• [LOW] added the PCB "resistor beams" the brief lists.
• [LOW] the demo's "Record Crate" teleport aimed into the left wall → re-aimed. (Two other raw findings were false positives — one described already-fixed code; a doc-comment nit I tightened anyway.) I added regression guards for the crate and anchors.

Cross-lane smoke test. Since all five lanes have now landed, I ran buildBooth against Lane A's real VoxelWorld (not my mock): the fillBox fast path engages (Lane A's signature + inclusive semantics match my assumption exactly), 30.7 ms build, and every acceptance check still passes. Lane C drops into the engine with zero friction.

4. Contract friction (needs an integrator/Fable call)

1. Mixer height: the brief says "tabletop → topY+40", but constants.ts + DESIGN both define the mixer face plate top surface as topY = 67. I built to 67 (with a raised rear ridge + VU towers for the "tallest mesa" look). Flag if a 107-tall mixer was actually intended — it's a one-liner.
2. fillBox signature: tools.box() calls world.fillBox(x0,y0,z0,x1,y1,z1,id) (inclusive) if Lane A provides it, else loops setBlock. buildBooth logs which path ran. Lane A should match that signature (or we reconcile at integration; the loop is always correct).

5. Handoff to Lane D (machines)

Lane D reads QUEST_POS + the exported anchors — no re-hardcoding coordinates. Every moving part has a socket waiting: platter wells, tonearm pedestal + headshell anchor, empty fader/crossfader slots, button/switch recesses. Anchor semantics are documented in src/worldgen/HANDOFF.md.

6. Suggested next steps for Fable

• Greenlight (or correct) the mixer-height interpretation in §4.1.
• Confirm the fillBox signature with Lane A so the fast path engages at integration.
• Lane D can start now against QUEST_POS + anchors; nothing blocks it.
• (Optional polish later) chunkier cable cross-sections, a lower/hinged glass dust cover, and more copper-trace detail in the PCB rooms.

7. Repo note

Work is in the shared working tree (/Users/jing/TURNCRAFT), not yet pushed. The fresh remote ssh://git@100.71.119.27:222/monster/TURNCRAFT.git is empty and there's no local git repo yet — I did not git init/push, since seeding a shared repo from one of five parallel lanes is an orchestration decision (whole scaffold + all lanes) better made by the integrator. Say the word and I'll initialize + push Lane C on a branch.