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() {
  type = "TorusGeometry";
  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);
    }
  }

  // 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));
}