sampleFace method

dynamic sampleFace(dynamic faceIndex, dynamic targetPosition, dynamic targetNormal, dynamic targetColor,)

Implementation

sampleFace(faceIndex, targetPosition, targetNormal, targetColor) {
  var u = this.randomFunction();
  var v = this.randomFunction();

  if (u + v > 1) {
    u = 1 - u;
    v = 1 - v;
  }

  _face.a.fromBufferAttribute(this.positionAttribute, faceIndex * 3);
  _face.b.fromBufferAttribute(this.positionAttribute, faceIndex * 3 + 1);
  _face.c.fromBufferAttribute(this.positionAttribute, faceIndex * 3 + 2);

  targetPosition
      .set(0, 0, 0)
      .addScaledVector(_face.a, u)
      .addScaledVector(_face.b, v)
      .addScaledVector(_face.c, 1 - (u + v));

  if (targetNormal != null) {
    _face.getNormal(targetNormal);
  }

  if (targetColor != null && this.colorAttribute != null) {
    _face.a.fromBufferAttribute(this.colorAttribute, faceIndex * 3);
    _face.b.fromBufferAttribute(this.colorAttribute, faceIndex * 3 + 1);
    _face.c.fromBufferAttribute(this.colorAttribute, faceIndex * 3 + 2);

    _color
        .set(0, 0, 0)
        .addScaledVector(_face.a, u)
        .addScaledVector(_face.b, v)
        .addScaledVector(_face.c, 1 - (u + v));

    targetColor.r = _color.x;
    targetColor.g = _color.y;
    targetColor.b = _color.z;
  }

  return this;
}