sphere static method

Geometry sphere({ bool normals = true, bool uvs = true, })

Implementation

static Geometry sphere({bool normals = true, bool uvs = true}) {
  int latitudeBands = 20;
  int longitudeBands = 20;

  List<double> verticesList = [];
  List<double> normalsList = [];
  List<double> uvsList = [];
  List<int> indices = [];

  for (int latNumber = 0; latNumber <= latitudeBands; latNumber++) {
    double theta = latNumber * pi / latitudeBands;
    double sinTheta = sin(theta);
    double cosTheta = cos(theta);

    for (int longNumber = 0; longNumber <= longitudeBands; longNumber++) {
      double phi = longNumber * 2 * pi / longitudeBands;
      double sinPhi = sin(phi);
      double cosPhi = cos(phi);

      double x = cosPhi * sinTheta;
      double y = cosTheta;
      double z = sinPhi * sinTheta;

      verticesList.addAll([x, y, z]);
      normalsList.addAll([x, y, z]);

      uvsList.addAll([longNumber / longitudeBands, latNumber / latitudeBands]);
    }
  }

  for (int latNumber = 0; latNumber < latitudeBands; latNumber++) {
    for (int longNumber = 0; longNumber < longitudeBands; longNumber++) {
      int first = (latNumber * (longitudeBands + 1)) + longNumber;
      int second = first + longitudeBands + 1;

      indices.addAll([first, second, first + 1, second, second + 1, first + 1]);
    }
  }

  Float32List vertices = Float32List.fromList(verticesList);
  Float32List? _normals = normals ? Float32List.fromList(normalsList) : null;
  Float32List? _uvs = uvs ? Float32List.fromList(uvsList) : null;

  return Geometry(vertices, indices, normals: _normals, uvs: _uvs);
}