rotate method

  1. @override
Rectangle rotate(
  1. double angle, [
  2. Point<num>? origin
])
override

Rotates the shape by the given angle (in radians) around the origin. If origin is omitted, rotates around the shape's centroid.

Implementation

@override
Rectangle rotate(double angle, [Point<num>? origin]) {
  final rotOrigin = origin ?? centroid;
  final ox = rotOrigin.x.toDouble();
  final oy = rotOrigin.y.toDouble();
  final cx = _center.x.toDouble();
  final cy = _center.y.toDouble();

  final cosA = math.cos(angle);
  final sinA = math.sin(angle);

  final nx = cosA * (cx - ox) - sinA * (cy - oy) + ox;
  final ny = sinA * (cx - ox) + cosA * (cy - oy) + oy;

  final absCos = cosA.abs();
  final absSin = sinA.abs();

  final newWidth = width * absCos + height * absSin;
  final newHeight = width * absSin + height * absCos;

  return Rectangle(width: newWidth, height: newHeight, center: Point(x: nx, y: ny));
}