Class Simple3MFLoader

threemf-loader-simple.js:9–388

const {
  PREVIEW_3MF_TARGET_TRIANGLES,
  extractAllMeshesFast,
  simplifyForPreview,
  shouldUseFastPath,
  modelHasPlacementTransforms
} = require('./threemf-mesh-extract.js');

/** Identity 4x4 matrix, column-major (THREE.Matrix4 layout). */
function mat4Identity() {
  return new Float32Array([
    1, 0, 0, 0,
    0, 1, 0, 0,
    0, 0, 1, 0,
    0, 0, 0, 1
  ]);
}

/**
 * Parse 3MF transform="a b c d e f g h i tx ty tz" into a column-major 4x4
 * matching THREE.3MFLoader / the 3MF spec.
 */
function parseTransformAttr(transform) {
  if (!transform || typeof transform !== 'string') return null;
  const t = transform.trim().split(/\s+/).map(parseFloat);
  if (t.length < 12 || t.some(n => Number.isNaN(n))) return null;
  // THREE.Matrix4.set(n11,n12,n13,n14, n21,...) then .elements is column-major
  return new Float32Array([
    t[0], t[1], t[2], 0,
    t[3], t[4], t[5], 0,
    t[6], t[7], t[8], 0,
    t[9], t[10], t[11], 1
  ]);
}

function mat4Multiply(a, b) {
  const out = new Float32Array(16);
  for (let col = 0; col < 4; col++) {
    for (let row = 0; row < 4; row++) {
      out[col * 4 + row] =
        a[0 * 4 + row] * b[col * 4 + 0] +
        a[1 * 4 + row] * b[col * 4 + 1] +
        a[2 * 4 + row] * b[col * 4 + 2] +
        a[3 * 4 + row] * b[col * 4 + 3];
    }
  }
  return out;
}

function mat4ApplyPoint(m, x, y, z) {
  return {
    x: m[0] * x + m[4] * y + m[8] * z + m[12],
    y: m[1] * x + m[5] * y + m[9] * z + m[13],
    z: m[2] * x + m[6] * y + m[10] * z + m[14]
  };
}

function isIdentityMatrix(m) {
  if (!m) return true;
  const id = mat4Identity();