{
  "$schema": "https://ui.shadcn.com/schema/registry-item.json",
  "name": "cable-tray",
  "type": "registry:component",
  "title": "Cable tray run",
  "description": "Ladder-type cable tray run after IEC 61537: 1 to 6 stacked trays (C-section side rails, rungs at 300 mm, splice plates at 3 m, copper earth bonding jumpers, laid cables at a set fill) on floor-standing 41 × 41 strut posts with gusseted cantilever arms, base plates and anchors, floor braces and an optional top cover. Run along X centred on the origin; posts on y = 0 on the −Z side; the lowest rungs at y = elevation, tiers every tierSpacing.",
  "dependencies": [
    "three",
    "@react-three/fiber",
    "@react-three/drei"
  ],
  "registryDependencies": [
    "https://deck-twin-library.demoareeb.workers.dev/r/core.json"
  ],
  "files": [
    {
      "path": "structure/cable-tray.tsx",
      "type": "registry:file",
      "target": "components/deck-twin/structure/cable-tray.tsx",
      "content": "// Ladder-type cable tray run (IEC 61537) on floor-standing strut supports: multi-tier trays at 300 mm, cantilever arms, laid cables, splice plates, earth bonding and optional covers.\nimport type { Kit, MatKey } from '../lib/kit'\nimport { KitMesh, useKit, type GroupProps } from '../lib/mesh'\nimport { anchorBolt, boxMM } from './_steel'\nimport { ladderTray } from './_tray'\n\nexport interface CableTrayProps {\n  /** along X, m */\n  length?: number\n  /** tray width, m */\n  width?: number\n  tiers?: number\n  /** tier spacing, m */\n  tierSpacing?: number\n  /** rung level of the lowest tier above y = 0, m */\n  elevation?: number\n  /** support spacing, m */\n  supportSpacing?: number\n  /** cable fill, 0…1 */\n  fill?: number\n  /** cover on the top tier */\n  cover?: boolean\n  material?: 'galvanised' | 'stainless'\n}\n\nexport const defaults = {\n  length: 6,\n  width: 0.6,\n  tiers: 3,\n  tierSpacing: 0.3,\n  elevation: 0.6,\n  supportSpacing: 2,\n  fill: 0.6,\n  cover: false,\n  material: 'galvanised' as 'galvanised' | 'stainless',\n}\n\ntype P = typeof defaults\n\nexport function CableTray(props: CableTrayProps & GroupProps) {\n  const { length, width, tiers, tierSpacing, elevation, supportSpacing, fill, cover, material, ...group } = { ...defaults, ...props }\n  const data = useKit((k) => build(k, { length, width, tiers, tierSpacing, elevation, supportSpacing, fill, cover, material }), [length, width, tiers, tierSpacing, elevation, supportSpacing, fill, cover, material])\n  return (\n    <group {...group}>\n      <KitMesh data={data} />\n    </group>\n  )\n}\n\nexport default CableTray\n\nconst STRUT = 0.041 // 41 × 41 slotted strut channel\n\nfunction build(k: Kit, p: P) {\n  const mat: MatKey = p.material === 'stainless' ? 'stainless' : 'galvanised'\n  const L = Math.max(1, p.length)\n  const W = Math.max(0.1, p.width)\n  const n = Math.max(1, Math.round(p.tiers))\n  const sp = Math.max(0.2, p.tierSpacing)\n  const ys = Array.from({ length: n }, (_, i) => p.elevation + i * sp)\n  const top = ys[n - 1] + 0.1\n  // supports: a single back-to-back strut post at -Z with cantilever arms under each tier, braced to the floor\n  const zp = -W / 2 - 0.06\n  const m = Math.max(1, Math.ceil(L / Math.max(0.5, p.supportSpacing)))\n  for (let i = 0; i <= m; i++) {\n    const x = -L / 2 + 0.25 + ((L - 0.5) * i) / m\n    k.box(mat, [0.16, 0.01, 0.16], [x, 0.005, zp])\n    for (const a of [-1, 1]) anchorBolt(k, x + a * 0.055, 0.01, zp, 0.012)\n    boxMM(k, mat, [x - STRUT, 0.01, zp - STRUT / 2], [x + STRUT, top + 0.15, zp + STRUT / 2])\n    k.box('nut', [0.002, top + 0.12, 0.012], [x, (top + 0.15) / 2, zp + STRUT / 2 + 0.001]) // slot\n    k.box(mat, [0.09, 0.006, 0.09], [x, top + 0.153, zp])\n    for (const y of ys) {\n      // cantilever arm with a gusseted root bracket\n      boxMM(k, mat, [x - STRUT / 2, y - STRUT - 0.004, zp + STRUT / 2], [x + STRUT / 2, y - 0.004, zp + W + 0.12])\n      k.box(mat, [0.008, 0.12, 0.1], [x, y - 0.06, zp + STRUT / 2 + 0.05])\n      k.hex('nut', 0.018, 0.009, [x + STRUT / 2 + 0.005, y - 0.03, zp + STRUT / 2 + 0.03], 'x')\n    }\n    // floor brace on the open side\n    if (n > 1 || p.elevation > 0.8) {\n      const dx = Math.min(0.5, (L - 0.5) / m / 2)\n      const s = i === m ? -1 : 1\n      k.rod(mat, [x + s * dx, 0.02, zp], [x + s * STRUT, Math.min(ys[0] - 0.1, 0.9), zp], 0.012, 6)\n    }\n  }\n  for (const y of ys) ladderTray(k, -L / 2, L / 2, zp + STRUT / 2 + 0.06 + W / 2, y, W, { fill: p.fill, mat: p.material === 'stainless' ? 'stainless' : 'cableTray' })\n  const zc = zp + STRUT / 2 + 0.06 + W / 2\n  // earth bonding jumpers across the splices on each tier\n  for (const y of ys)\n    for (let x = -L / 2 + 3; x < L / 2 - 0.2; x += 3) k.tube('copper', [[x - 0.12, y + 0.05, zc - W / 2 - 0.006], [x, y + 0.02, zc - W / 2 - 0.02], [x + 0.12, y + 0.05, zc - W / 2 - 0.006]], 0.005, 6, 0.03)\n  if (p.cover) {\n    const yc = ys[n - 1] + 0.1 + 0.004\n    k.box(mat, [L, 0.0015, W + 0.03], [0, yc, zc])\n    for (const s of [-1, 1]) k.box(mat, [L, 0.025, 0.0015], [0, yc - 0.012, zc + s * (W / 2 + 0.015)])\n  }\n}\n"
    },
    {
      "path": "structure/_steel.ts",
      "type": "registry:file",
      "target": "components/deck-twin/structure/_steel.ts",
      "content": "// Shared structural steel details: sections placed by top of steel, plate girders, base/cap/end/fin plates, bolts, gussets, grating bays, ISO 14122 guard rails and gates.\nimport * as THREE from 'three'\nimport { mat4, uvScale, type Kit, type MatKey, type V3 } from '../lib/kit'\nimport { sectionShape } from '../lib/parts'\nimport { ACCESS, SECTIONS, type Section } from '../lib/standards'\nimport { gratingMaterial, hazardStripeMaterial } from '../lib/textures'\n\nexport const clamp = (v: number, a: number, b: number) => Math.min(b, Math.max(a, v))\n\n/** Section by name. Also accepts welded plate girders \"PG <depth mm>[x<flange mm>]\", e.g. \"PG 1200\" or \"PG 1500x500\". */\nexport function sec(name: string): Section {\n  const m = /^PG\\s*(\\d+)(?:\\s*[xX]\\s*(\\d+))?$/.exec(String(name).trim())\n  if (m) {\n    const d = +m[1] / 1000\n    const b = m[2] ? +m[2] / 1000 : Math.round(d * 0.38 * 20) / 20 // typical\n    const tw = clamp(Math.round(d / 70 / 0.002) * 0.002, 0.012, 0.03) // typical\n    const tf = clamp(Math.round(d / 32 / 0.005) * 0.005, 0.025, 0.07) // typical\n    return { kind: 'I', d, b, tw, tf, r: 0, mass: (2 * b * tf + (d - 2 * tf) * tw) * 7850 }\n  }\n  return SECTIONS[name] ?? SECTIONS['HEB 300']\n}\n\nfunction shapeOf(name: string): THREE.Shape {\n  if (!/^PG/i.test(String(name).trim())) return sectionShape(SECTIONS[name] ? name : 'HEB 300')\n  const { d, b, tw, tf } = sec(name)\n  const sh = new THREE.Shape()\n  sh.moveTo(-b / 2, -d / 2).lineTo(b / 2, -d / 2).lineTo(b / 2, -d / 2 + tf).lineTo(tw / 2, -d / 2 + tf)\n  sh.lineTo(tw / 2, d / 2 - tf).lineTo(b / 2, d / 2 - tf).lineTo(b / 2, d / 2).lineTo(-b / 2, d / 2)\n  sh.lineTo(-b / 2, d / 2 - tf).lineTo(-tw / 2, d / 2 - tf).lineTo(-tw / 2, -d / 2 + tf).lineTo(-b / 2, -d / 2 + tf).closePath()\n  return sh\n}\n\n/** Member of any section (incl. plate girders) between a and b; `up` is the depth (web) direction. */\nexport function bar(k: Kit, a: V3, b: V3, name: string, mat: MatKey = 'structSteel', up: V3 = [0, 1, 0]) {\n  const A = new THREE.Vector3(...a)\n  const z = new THREE.Vector3(...b).sub(A)\n  const L = z.length()\n  if (L < 1e-4) return\n  z.normalize()\n  let u = new THREE.Vector3(...up).normalize()\n  if (Math.abs(u.dot(z)) > 0.99) u = Math.abs(z.y) > 0.9 ? new THREE.Vector3(1, 0, 0) : new THREE.Vector3(0, 1, 0)\n  const x = new THREE.Vector3().crossVectors(u, z).normalize()\n  const y = new THREE.Vector3().crossVectors(z, x).normalize()\n  const s = sec(name)\n  k.extrude(mat, shapeOf(name), L, new THREE.Matrix4().makeBasis(x, y, z).setPosition(A), s.kind === 'CHS' ? 10 : 4)\n}\n\n/** Horizontal beam with its top of steel at `tos`, web vertical. */\nexport function beamTOS(k: Kit, x0: number, z0: number, x1: number, z1: number, tos: number, name: string, mat: MatKey = 'structSteel') {\n  const h = sec(name).d / 2\n  bar(k, [x0, tos - h, z0], [x1, tos - h, z1], name, mat, [0, 1, 0])\n}\n\n/** Vertical column from y0 to y1; `web` is the axis the web (depth) runs along. */\nexport function column(k: Kit, x: number, z: number, y0: number, y1: number, name: string, mat: MatKey = 'structSteel', web: 'x' | 'z' = 'x') {\n  bar(k, [x, y0, z], [x, y1, z], name, mat, web === 'x' ? [1, 0, 0] : [0, 0, 1])\n}\n\n/** Axis-aligned box from min to max corner. */\nexport function boxMM(k: Kit, mat: MatKey, a: V3, b: V3) {\n  const s: V3 = [Math.abs(b[0] - a[0]), Math.abs(b[1] - a[1]), Math.abs(b[2] - a[2])]\n  if (s[0] < 1e-5 || s[1] < 1e-5 || s[2] < 1e-5) return\n  k.box(mat, s, [(a[0] + b[0]) / 2, (a[1] + b[1]) / 2, (a[2] + b[2]) / 2])\n}\n\n/** Box oriented along a→b (length), with cross-section w (horizontal, ⟂) × h (in the plane containing `up`). */\nexport function strip(k: Kit, mat: MatKey, a: V3, b: V3, w: number, h: number, up: V3 = [0, 1, 0]) {\n  const A = new THREE.Vector3(...a)\n  const z = new THREE.Vector3(...b).sub(A)\n  const L = z.length()\n  if (L < 1e-5) return\n  z.normalize()\n  let u = new THREE.Vector3(...up).normalize()\n  if (Math.abs(u.dot(z)) > 0.99) u = new THREE.Vector3(1, 0, 0)\n  const x = new THREE.Vector3().crossVectors(u, z).normalize()\n  const y = new THREE.Vector3().crossVectors(z, x).normalize()\n  const m = new THREE.Matrix4().makeBasis(x, y, z).setPosition(A.add(new THREE.Vector3(...b)).multiplyScalar(0.5))\n  k.add(mat, new THREE.BoxGeometry(w, h, L), m)\n}\n\n/** Bolt (stud + nut each side) through a plate pack centred at p, along `axis`. */\nexport function bolt(k: Kit, p: V3, axis: V3, dia = 0.02, grip = 0.03, mat: MatKey = 'galvanised') {\n  const v = new THREE.Vector3(...axis).normalize()\n  const P = new THREE.Vector3(...p)\n  const e = grip / 2 + dia * 0.5\n  k.rod(mat, P.clone().addScaledVector(v, -e - dia * 0.3).toArray() as V3, P.clone().addScaledVector(v, e + dia * 0.3).toArray() as V3, dia / 2, 6)\n  for (const s of [-1, 1]) k.hex('nut', dia * 1.8, dia * 0.8, P.clone().addScaledVector(v, s * (grip / 2 + dia * 0.4)).toArray() as V3, axis)\n}\n\n/** Anchor bolt projecting above a base plate whose top is at y: stud, washer and nut. */\nexport function anchorBolt(k: Kit, x: number, y: number, z: number, dia = 0.024) {\n  k.cyl('galvanised', dia / 2, dia * 3, [x, y + dia * 1.5 - 0.01, z], 'y', 6)\n  k.cyl('galvanised', dia * 1.1, 0.004, [x, y + 0.002, z], 'y', 10)\n  k.hex('nut', dia * 1.8, dia * 0.8, [x, y + 0.004 + dia * 0.4, z], 'y')\n}\n\n/** Base plate (bottom at y) with anchor bolts at the corners and an optional grout bed below. Returns the plate top. */\nexport function basePlate(k: Kit, x: number, y: number, z: number, sx: number, sz: number, t = 0.025, dia = 0.024, mat: MatKey = 'structSteel', grout = 0) {\n  if (grout > 0) k.box('concrete', [sx + 0.08, grout, sz + 0.08], [x, y - grout / 2, z])\n  k.box(mat, [sx, t, sz], [x, y + t / 2, z])\n  const e = Math.max(0.045, dia * 2)\n  for (const a of [-1, 1]) for (const b of [-1, 1]) anchorBolt(k, x + a * (sx / 2 - e), y + t, z + b * (sz / 2 - e), dia)\n  return y + t\n}\n\n/** Triangular gusset plate: right angle at `corner`, legs la along dirA and lb along dirB, thickness t. */\nexport function gusset(k: Kit, corner: V3, dirA: V3, dirB: V3, la: number, lb: number, t = 0.012, mat: MatKey = 'structSteel') {\n  const a = new THREE.Vector3(...dirA).normalize()\n  const b = new THREE.Vector3(...dirB).normalize()\n  const n = new THREE.Vector3().crossVectors(a, b).normalize()\n  const c = Math.min(la, lb) * 0.12 // snipe at the root\n  const sh = new THREE.Shape()\n  sh.moveTo(c, 0).lineTo(la, 0).lineTo(la, lb * 0.1).lineTo(la * 0.1, lb).lineTo(0, lb).lineTo(0, c).closePath()\n  const o = new THREE.Vector3(...corner).addScaledVector(n, -t / 2)\n  k.extrude(mat, sh, t, new THREE.Matrix4().makeBasis(a, b, n).setPosition(o), 1)\n}\n\n/** Full-depth web stiffener pair on a horizontal beam (along `along` = 'x'|'z') at position p (centre of the beam). */\nexport function webStiffeners(k: Kit, p: V3, along: 'x' | 'z', s: Section, mat: MatKey = 'structSteel') {\n  const h = s.d - 2 * s.tf\n  const w = (s.b - s.tw) / 2 - 0.004\n  const t = clamp(s.tw * 1.2, 0.008, 0.025)\n  for (const sg of [-1, 1]) {\n    const off = sg * (s.tw / 2 + w / 2)\n    if (along === 'x') k.box(mat, [t, h, w], [p[0], p[1], p[2] + off])\n    else k.box(mat, [w, h, t], [p[0] + off, p[1], p[2]])\n  }\n}\n\n/**\n * Bolted end-plate connection at the end of a horizontal beam (along x or z): the beam ends at `p` (web centre) and the\n * plate runs from p to p + dir·t, where `dir` = +1/-1 points from the beam out through the plate.\n */\nexport function endPlate(k: Kit, p: V3, along: 'x' | 'z', dir: number, s: Section, mat: MatKey = 'structSteel') {\n  const t = s.d > 0.5 ? 0.025 : 0.02\n  const h = s.d + 0.03\n  const w = s.b + 0.02\n  const c: V3 = along === 'x' ? [p[0] + dir * t / 2, p[1], p[2]] : [p[0], p[1], p[2] + dir * t / 2]\n  k.box(mat, along === 'x' ? [t, h, w] : [w, h, t], c)\n  const rows = Math.max(2, Math.min(6, Math.floor((s.d - 0.06) / 0.09)))\n  const g = Math.min(w * 0.6, 0.14) / 2\n  const dia = s.d > 0.5 ? 0.024 : 0.02\n  for (let i = 0; i < rows; i++) {\n    const y = p[1] - s.d / 2 + 0.05 + ((s.d - 0.1) * i) / (rows - 1)\n    for (const sg of [-1, 1]) {\n      const q: V3 = along === 'x' ? [c[0], y, c[2] + sg * g] : [c[0] + sg * g, y, c[2]]\n      bolt(k, q, along === 'x' ? [1, 0, 0] : [0, 0, 1], dia, t * 2)\n    }\n  }\n}\n\n/** Fin-plate shear connection: plate welded to a supporting web face at `p`, projecting `len` along ±x|z, bolted to the supported web. */\nexport function finPlate(k: Kit, p: V3, along: 'x' | 'z', dir: number, depth: number, len = 0.13, mat: MatKey = 'structSteel') {\n  const h = clamp(depth * 0.7, 0.12, 0.6)\n  const t = 0.01\n  const c: V3 = along === 'x' ? [p[0] + dir * len / 2, p[1], p[2] + 0.011] : [p[0] + 0.011, p[1], p[2] + dir * len / 2]\n  k.box(mat, along === 'x' ? [len, h, t] : [t, h, len], c)\n  const n = Math.max(2, Math.floor(h / 0.075))\n  for (let i = 0; i < n; i++) {\n    const y = p[1] - h / 2 + 0.04 + ((h - 0.08) * i) / Math.max(1, n - 1)\n    const q: V3 = along === 'x' ? [p[0] + dir * (len - 0.045), y, p[2] + 0.006] : [p[0] + 0.006, y, p[2] + dir * (len - 0.045)]\n    bolt(k, q, along === 'x' ? [0, 0, 1] : [1, 0, 0], 0.016, 0.026)\n  }\n}\n\n/**\n * Bar-grating bay from (x0,z0) to (x1,z1), top at `top`: one textured box plus flat-bar banding.\n * `bars` = direction the bearing bars run (they span between the supports).\n */\nexport function gratingBay(k: Kit, x0: number, z0: number, x1: number, z1: number, top: number, bars: 'x' | 'z' = 'z', t = 0.03, band = true) {\n  const sx = Math.abs(x1 - x0)\n  const sz = Math.abs(z1 - z0)\n  if (sx < 0.02 || sz < 0.02) return\n  const g = new THREE.BoxGeometry(sx, t, sz)\n  uvScale(g, sx / 0.3, sz / 0.3)\n  if (bars === 'x') {\n    const uv = g.getAttribute('uv') as THREE.BufferAttribute\n    for (let i = 0; i < uv.count; i++) uv.setXY(i, uv.getY(i), uv.getX(i))\n  }\n  const cx = (x0 + x1) / 2\n  const cz = (z0 + z1) / 2\n  k.add(gratingMaterial(), g, mat4([cx, top - t / 2, cz]))\n  if (!band) return\n  const bt = 0.004\n  for (const s of [-1, 1]) {\n    k.box('galvanised', [sx, t, bt], [cx, top - t / 2, cz + s * (sz / 2 - bt / 2)])\n    k.box('galvanised', [bt, t, sz - 2 * bt], [cx + s * (sx / 2 - bt / 2), top - t / 2, cz])\n  }\n}\n\n/** Hazard-striped (black/yellow) band from a to b, w wide and h tall, oriented like strip(). Stripe pitch ~0.2 m. */\nexport function hazardBand(k: Kit, a: V3, b: V3, w: number, h: number, up: V3 = [0, 1, 0]) {\n  const L = Math.hypot(b[0] - a[0], b[1] - a[1], b[2] - a[2])\n  const A = new THREE.Vector3(...a)\n  const z = new THREE.Vector3(...b).sub(A).normalize()\n  let u = new THREE.Vector3(...up).normalize()\n  if (Math.abs(u.dot(z)) > 0.99) u = new THREE.Vector3(1, 0, 0)\n  const x = new THREE.Vector3().crossVectors(u, z).normalize()\n  const y = new THREE.Vector3().crossVectors(z, x).normalize()\n  // box with its length along local X so the stripe texture repeats along U\n  const g = new THREE.BoxGeometry(L, h, w)\n  uvScale(g, L / 0.25, 1)\n  const m = new THREE.Matrix4().makeBasis(z, y, x.clone().negate()).setPosition(A.add(new THREE.Vector3(...b)).multiplyScalar(0.5))\n  k.add(hazardStripeMaterial(), g, m)\n}\n\n// ------------------------------------------------------------------ guard rails (ISO 14122-3)\n\nexport const RAIL = {\n  top: ACCESS.handrail.height,\n  knee: ACCESS.handrail.kneeRail,\n  toe: ACCESS.handrail.toePlate,\n  postR: 0.0242, // 48.3 mm tube\n  railR: 0.0212, // 42.4 mm\n  kneeR: 0.0169, // 33.7 mm\n  maxPost: ACCESS.handrail.postSpacingMax,\n}\n\nexport interface RailOpts {\n  top?: number\n  knee?: number\n  /** toe plate on the walking edge */\n  toe?: boolean\n  startPost?: boolean\n  endPost?: boolean\n  /** square base plate under each post */\n  basePlates?: boolean\n  mat?: MatKey\n}\n\n/** Straight guard-rail run a → b; a and b are on the walking surface (may slope). */\nexport function railRun(k: Kit, a: V3, b: V3, o: RailOpts = {}) {\n  const { top = RAIL.top, knee = RAIL.knee, toe = true, startPost = true, endPost = true, basePlates = true, mat = 'safetyYellow' } = o\n  const dx = b[0] - a[0]\n  const dy = b[1] - a[1]\n  const dz = b[2] - a[2]\n  const L = Math.hypot(dx, dz)\n  if (L < 0.08) return\n  const n = Math.max(1, Math.ceil(L / RAIL.maxPost))\n  for (let i = 0; i <= n; i++) {\n    if ((i === 0 && !startPost) || (i === n && !endPost)) continue\n    const t = i / n\n    const p: V3 = [a[0] + dx * t, a[1] + dy * t, a[2] + dz * t]\n    k.rod(mat, p, [p[0], p[1] + top, p[2]], RAIL.postR, 8)\n    if (basePlates) k.box(mat, [0.1, 0.01, 0.1], [p[0], p[1] + 0.005, p[2]])\n  }\n  k.rod(mat, [a[0], a[1] + top, a[2]], [b[0], b[1] + top, b[2]], RAIL.railR, 8)\n  k.rod(mat, [a[0], a[1] + knee, a[2]], [b[0], b[1] + knee, b[2]], RAIL.kneeR, 8)\n  if (startPost) k.sphere(mat, RAIL.railR * 1.15, [a[0], a[1] + top, a[2]], undefined, 8)\n  if (endPost) k.sphere(mat, RAIL.railR * 1.15, [b[0], b[1] + top, b[2]], undefined, 8)\n  if (toe) strip(k, mat, [a[0], a[1] + 0.005 + RAIL.toe / 2, a[2]], [b[0], b[1] + 0.005 + RAIL.toe / 2, b[2]], 0.006, RAIL.toe)\n}\n\n/**\n * Guard rail along a polyline of (x, z) points at height y, leaving gaps [s0, s1] (metres along the line) open.\n * `ends` drops the post at the very start / end of the polyline (where a neighbouring run already has one).\n */\nexport function railPath(k: Kit, pts: [number, number][], y: number, gaps: [number, number][] = [], closed = false, o: RailOpts = {}, ends: [boolean, boolean] = [true, true]) {\n  const P = closed ? [...pts, pts[0]] : pts\n  let s = 0\n  for (let i = 0; i < P.length - 1; i++) {\n    const [x0, z0] = P[i]\n    const [x1, z1] = P[i + 1]\n    const L = Math.hypot(x1 - x0, z1 - z0)\n    let pieces: [number, number][] = [[0, L]]\n    for (const [g0, g1] of gaps) {\n      const a = g0 - s\n      const b = g1 - s\n      const next: [number, number][] = []\n      for (const [p0, p1] of pieces) {\n        if (b <= p0 || a >= p1) next.push([p0, p1])\n        else {\n          if (a > p0) next.push([p0, a])\n          if (b < p1) next.push([b, p1])\n        }\n      }\n      pieces = next\n    }\n    const ux = (x1 - x0) / L\n    const uz = (z1 - z0) / L\n    for (const [p0, p1] of pieces) {\n      if (p1 - p0 < 0.1) continue\n      const startPost = !(i === 0 && p0 < 1e-6 && !ends[0] && !closed)\n      const endPost = !(i === P.length - 2 && p1 > L - 1e-6 && !ends[1] && !closed)\n      railRun(k, [x0 + ux * p0, y, z0 + uz * p0], [x0 + ux * p1, y, z0 + uz * p1], { ...o, startPost, endPost })\n    }\n    s += L\n  }\n}\n\n/** Self-closing swing gate (shown closed) across an opening from hinge point h to latch point e on the walking surface. */\nexport function gate(k: Kit, h: V3, e: V3, mat: MatKey = 'safetyYellow') {\n  const d = new THREE.Vector3(e[0] - h[0], 0, e[2] - h[2])\n  const L = d.length()\n  d.normalize()\n  const at = (s: number, y: number): V3 => [h[0] + d.x * s, h[1] + y, h[2] + d.z * s]\n  const g0 = 0.06\n  const g1 = L - 0.05\n  const r = 0.0169\n  // frame: two verticals, top rail, mid rail, diagonal\n  for (const s of [g0, g1]) k.rod(mat, at(s, 0.15), at(s, RAIL.top - 0.02), r, 8)\n  k.rod(mat, at(g0, RAIL.top - 0.02), at(g1, RAIL.top - 0.02), r, 8)\n  k.rod(mat, at(g0, RAIL.knee), at(g1, RAIL.knee), r * 0.9, 8)\n  k.rod(mat, at(g0, 0.15), at(g1, 0.15), r * 0.9, 8)\n  // hinge barrels with spring housings on the hinge post side\n  for (const y of [0.3, 0.9]) {\n    k.cyl('galvanised', 0.022, 0.09, at(0.03, y), 'y', 10)\n    k.box('galvanised', [0.03, 0.012, 0.03], at(0.045, y))\n  }\n  k.cyl('nut', 0.026, 0.05, at(0.03, 0.96), 'y', 10)\n  // latch stop on the far post\n  k.box(mat, [0.05, 0.05, 0.05], at(L - 0.01, RAIL.knee + 0.1))\n}\n\n/** Toe plate / coaming only (no rail), a → b at walking-surface level. */\nexport function toePlate(k: Kit, a: V3, b: V3, h: number = RAIL.toe, mat: MatKey = 'safetyYellow') {\n  strip(k, mat, [a[0], a[1] + h / 2, a[2]], [b[0], b[1] + h / 2, b[2]], 0.008, h)\n}\n"
    },
    {
      "path": "structure/_tray.ts",
      "type": "registry:file",
      "target": "components/deck-twin/structure/_tray.ts",
      "content": "// Shared ladder-type cable tray (IEC 61537): C-section side rails, rungs at 300 mm, laid cables, splice plates.\nimport type { Kit, MatKey } from '../lib/kit'\nimport { boxMM } from './_steel'\n\nexport interface TrayOpts {\n  /** side-rail height, m */\n  rail?: number\n  /** fraction of the tray width filled with cables, 0…1 */\n  fill?: number\n  mat?: MatKey\n  /** splice plates every n metres (standard 3 m lengths) */\n  splice?: number\n}\n\n/** Ladder tray along X from x0 to x1, centred on z = zc, rungs' bottom at y. Returns the tray top. */\nexport function ladderTray(k: Kit, x0: number, x1: number, zc: number, y: number, w: number, o: TrayOpts = {}) {\n  const h = o.rail ?? 0.1\n  const mat = o.mat ?? 'cableTray'\n  const t = 0.002\n  const lip = 0.022\n  for (const s of [-1, 1]) {\n    const z = zc + s * (w / 2)\n    boxMM(k, mat, [x0, y, z - t / 2], [x1, y + h, z + t / 2])\n    boxMM(k, mat, [x0, y + h - t, z - s * lip], [x1, y + h, z])\n    boxMM(k, mat, [x0, y, z - s * lip], [x1, y + t, z])\n    const sp = o.splice ?? 3\n    for (let x = x0 + sp; x < x1 - 0.2; x += sp) boxMM(k, 'galvanised', [x - 0.09, y + 0.015, z + s * t / 2], [x + 0.09, y + h - 0.015, z + s * (t / 2 + 0.004)])\n  }\n  for (let x = x0 + 0.15; x < x1 - 0.05; x += 0.3) boxMM(k, mat, [x - 0.015, y, zc - w / 2 + t], [x + 0.015, y + 0.022, zc + w / 2 - t])\n  const fill = Math.max(0, Math.min(1, o.fill ?? 0.6))\n  if (fill <= 0) return y + h\n  // cables: deterministic mix of diameters laid side by side\n  const D = [0.052, 0.034, 0.041, 0.026, 0.06, 0.03, 0.045, 0.022]\n  let z = zc - w / 2 + 0.02\n  let i = 0\n  const zEnd = zc - w / 2 + 0.02 + (w - 0.04) * fill\n  while (z < zEnd) {\n    const d = D[i % D.length]\n    if (z + d > zc + w / 2 - 0.01) break\n    k.cyl('cable', d / 2, x1 - x0 - 0.06, [(x0 + x1) / 2, y + 0.022 + d / 2, z + d / 2], 'x', 8)\n    if (i % 3 === 0 && d < 0.045) k.cyl('cable', d / 2, x1 - x0 - 0.06, [(x0 + x1) / 2, y + 0.022 + d + d / 2, z + d / 2], 'x', 8)\n    z += d + 0.004\n    i++\n  }\n  return y + h\n}\n"
    }
  ],
  "categories": [
    "structure"
  ],
  "meta": {
    "export": "CableTray",
    "anchor": "base",
    "standards": [
      "IEC 61537",
      "NEMA VE 1",
      "NEMA VE 2"
    ]
  }
}