updateWireframeAttribute method

void updateWireframeAttribute(BufferGeometry geometry)

Implementation

void updateWireframeAttribute(BufferGeometry geometry) {
  List<int> indices = [];

  final geometryIndex = geometry.index;
  final geometryPosition = geometry.attributes["position"];
  int version = 0;

  if (geometryIndex != null) {
    final array = geometryIndex.array;
    version = geometryIndex.version;
    for (int i = 0, l = array.length; i < l; i += 3) {
      final a = array[i + 0].toInt();
      final b = array[i + 1].toInt();
      final c = array[i + 2].toInt();

      indices.addAll([a, b, b, c, c, a]);
    }
  }
  else {
    final array = geometryPosition.array;
    version = geometryPosition.version;

    for (int i = 0, l = (array.length ~/ 3) - 1; i < l; i += 3) {
      final a = i + 0;
      final b = i + 1;
      final c = i + 2;

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

  BufferAttribute attribute;
  final max = indices.getMaxValue();
  if (max != null && max > 65535) {
    attribute = Uint32BufferAttribute.fromList(indices, 1, false);
  }
  else {
    attribute = Uint16BufferAttribute.fromList(indices, 1, false);
  }

  attribute.version = version;

  // Updating index buffer in VAO now. See WebGLBindingStates

  final previousAttribute = wireframeAttributes.get(geometry);
  if (previousAttribute != null) attributes.remove(previousAttribute);
  wireframeAttributes.add(key: geometry, value: attribute);
}