Vertices constructor

Vertices(VertexMode mode, List<Offset> positions, { List<Offset> textureCoordinates, List<Color> colors, List<int> indices })

Creates a set of vertex data for use with Canvas.drawVertices.

The mode and positions parameters must not be null.

If the textureCoordinates or colors parameters are provided, they must be the same length as positions.

If the indices parameter is provided, all values in the list must be valid index values for positions.

Implementation

Vertices(
  VertexMode mode,
  List<Offset> positions, {
  List<Offset> textureCoordinates,
  List<Color> colors,
  List<int> indices,
}) : assert(mode != null),
     assert(positions != null) {
  if (textureCoordinates != null && textureCoordinates.length != positions.length)
    throw ArgumentError('"positions" and "textureCoordinates" lengths must match.');
  if (colors != null && colors.length != positions.length)
    throw ArgumentError('"positions" and "colors" lengths must match.');
  if (indices != null && indices.any((int i) => i < 0 || i >= positions.length))
    throw ArgumentError('"indices" values must be valid indices in the positions list.');

  final Float32List encodedPositions = _encodePointList(positions);
  final Float32List encodedTextureCoordinates = (textureCoordinates != null)
    ? _encodePointList(textureCoordinates)
    : null;
  final Int32List encodedColors = colors != null
    ? _encodeColorList(colors)
    : null;
  final Uint16List encodedIndices = indices != null
    ? Uint16List.fromList(indices)
    : null;

  _constructor();
  if (!_init(mode.index, encodedPositions, encodedTextureCoordinates, encodedColors, encodedIndices))
    throw ArgumentError('Invalid configuration for vertices.');
}