rotate method

Implementation

@override
Rectangle rotate(double deg) {
  // Rotation breaks axis-alignment, so rotate all corners
  // and return the bounding rectangle of the result
  final c = center;
  final rotated = vertices.map((v) {
    final dx = v.x - c.x;
    final dy = v.y - c.y;
    final rad = deg * math.pi / 180;
    final nx = dx * math.cos(rad) - dy * math.sin(rad) + c.x;
    final ny = dx * math.sin(rad) + dy * math.cos(rad) + c.y;
    return Point(nx, ny);
  }).toList();

  final minX = rotated.map((p) => p.x).reduce(math.min);
  final minY = rotated.map((p) => p.y).reduce(math.min);
  final maxX = rotated.map((p) => p.x).reduce(math.max);
  final maxY = rotated.map((p) => p.y).reduce(math.max);

  return Rectangle(
    x: minX,
    y: minY,
    width: maxX - minX,
    height: maxY - minY,
  );
}