area property

double get area

Calculates quadrilateral area using the Shoelace formula.

Implementation

double get area {
  final pts = toList();
  double sum1 = 0;
  double sum2 = 0;
  for (int i = 0; i < pts.length; i++) {
    final next = (i + 1) % pts.length;
    sum1 += pts[i].dx * pts[next].dy;
    sum2 += pts[i].dy * pts[next].dx;
  }
  return (sum1 - sum2).abs() / 2.0;
}