convert method

Implementation

@override
Uint32List convert(Buffer<int> input) {
  final width = input.width;
  final height = input.height;
  final data = input.data;

  // Convert every 32 pixels into 32-bits.
  // That is, a 128x128 bitmap is represented as 4x4 32-bit words.
  final output = Uint32List(2 + (data.length ~/ 32));
  output[0] = width;
  output[1] = height;

  var word = 0;
  var bit = 0;
  var offset = 2;
  for (final pixel in input.data) {
    if (pixel != input.format.zero) {
      word |= 1 << bit;
    }
    bit++;
    if (bit == 32) {
      output[offset] = word;
      word = 0;
      bit = 0;
      offset++;
    }
  }

  return output;
}