Function pushEdge

js/decimation.js:593–624

(heap, quadrics, positions, version, v1, v2)

                                q[o+7] += c*c; q[o+8] += c*d;
                                               q[o+9] += d*d;
}

function mergeQuadric(q, v1, v2) {
  const o1 = v1 * 10, o2 = v2 * 10;
  for (let i = 0; i < 10; i++) q[o1 + i] += q[o2 + i];
}

function evalQ(q, v, x, y, z) {
  const o = v * 10;
  return q[o]   * x*x + 2*q[o+1]*x*y + 2*q[o+2]*x*z + 2*q[o+3]*x
       + q[o+4] * y*y + 2*q[o+5]*y*z + 2*q[o+6]*y
       + q[o+7] * z*z + 2*q[o+8]*z
       + q[o+9];
}

function evalQSum(q, v1, v2, x, y, z) {
  return evalQ(q, v1, x, y, z) + evalQ(q, v2, x, y, z);
}

const _s = new Float64Array(3);

function solveQ(q, v1, v2) {
  const o1 = v1 * 10, o2 = v2 * 10;
  const a00 = q[o1]   + q[o2];
  const a01 = q[o1+1] + q[o2+1];
  const a02 = q[o1+2] + q[o2+2];
  const a11 = q[o1+4] + q[o2+4];
  const a12 = q[o1+5] + q[o2+5];
  const a22 = q[o1+7] + q[o2+7];
  const b0  = -(q[o1+3] + q[o2+3]);
  const b1  = -(q[o1+6] + q[o2+6]);
  const b2  = -(q[o1+8] + q[o2+8]);

  const det = a00*(a11*a22 - a12*a12) - a01*(a01*a22 - a12*a02) + a02*(a01*a12 - a11*a02);
  const maxEl = Math.max(Math.abs(a00), Math.abs(a01), Math.abs(a02), Math.abs(a11), Math.abs(a12), Math.abs(a22));