TorusGeometry constructor

TorusGeometry([ dynamic radius = 1, dynamic tube = 0.4, dynamic radialSegments = 8, dynamic tubularSegments = 6, dynamic arc = Math.PI * 2, ])

Implementation

TorusGeometry(
    [radius = 1,
    tube = 0.4,
    radialSegments = 8,
    tubularSegments = 6,
    arc = Math.PI * 2])
    : super() {
  parameters = {
    "radius": radius,
    "tube": tube,
    "radialSegments": radialSegments,
    "tubularSegments": tubularSegments,
    "arc": arc
  };

  radialSegments = Math.floor(radialSegments);
  tubularSegments = Math.floor(tubularSegments);

  // buffers

  List<num> indices = [];
  List<double> vertices = [];
  List<double> normals = [];
  List<double> uvs = [];

  // helper variables

  var center = Vector3();
  var vertex = Vector3();
  var normal = Vector3();

  // generate vertices, normals and uvs

  for (var j = 0; j <= radialSegments; j++) {
    for (var i = 0; i <= tubularSegments; i++) {
      var u = i / tubularSegments * arc;
      var v = j / radialSegments * Math.PI * 2;

      // vertex

      vertex.x = (radius + tube * Math.cos(v)) * Math.cos(u);
      vertex.y = (radius + tube * Math.cos(v)) * Math.sin(u);
      vertex.z = tube * Math.sin(v);

      vertices.addAll(
          [vertex.x.toDouble(), vertex.y.toDouble(), vertex.z.toDouble()]);

      // normal

      center.x = radius * Math.cos(u);
      center.y = radius * Math.sin(u);
      normal.subVectors(vertex, center).normalize();

      normals.addAll(
          [normal.x.toDouble(), normal.y.toDouble(), normal.z.toDouble()]);

      // uv

      uvs.add(i / tubularSegments);
      uvs.add(j / radialSegments);

      if(i > 0 && j > 0){
        final a = (tubularSegments + 1) * j + i - 1;
        final b = (tubularSegments + 1) * (j - 1) + i - 1;
        final c = (tubularSegments + 1) * (j - 1) + i;
        final d = (tubularSegments + 1) * j + i;

        indices.addAll([a,b,d]);
        indices.addAll([b,c,d]);
      }
    }
  }

  // generate indices

  // for (var j = 1; j <= radialSegments; j++) {
  //   for (var i = 1; i <= tubularSegments; i++) {
  //     // indices

  //     var a = (tubularSegments + 1) * j + i - 1;
  //     var b = (tubularSegments + 1) * (j - 1) + i - 1;
  //     var c = (tubularSegments + 1) * (j - 1) + i;
  //     var d = (tubularSegments + 1) * j + i;

  //     // faces

  //     indices.addAll([a, b, d]);
  //     indices.addAll([b, c, d]);
  //   }
  // }

  // build geometry

  setIndex(indices);
  setAttribute(
      'position', Float32BufferAttribute(Float32Array.from(vertices), 3));
  setAttribute(
      'normal', Float32BufferAttribute(Float32Array.from(normals), 3));
  setAttribute('uv', Float32BufferAttribute(Float32Array.from(uvs), 2));
}