isPointInsideContour method

bool isPointInsideContour(Point point, { bool raycasting = true, })

Implementation

bool isPointInsideContour(Point point, {bool raycasting = true}) {
  bool inside = false;

  if(!raycasting) {

    int i = 0;
    int j = Points.length - 1;

    for (; i < Points.length; j = i++) {
      final pi = Points[i];
      final pj = Points[j];

      if (((pi.y > point.y) != (pj.y > point.y)) &&
          (point.x <
              (pj.x - pi.x) * (point.y - pi.y) / (pj.y - pi.y) + pi.x)) {
        inside = !inside;
      }
    }

  }else{
    int count = 0;
    final int n = Points.length;

    for (int i = 0, j = n - 1; i < n; j = i++) {
      final pi = Points[i];
      final pj = Points[j];

      if (((pi.y > point.y) != (pj.y > point.y)) &&
          (point.x < (pj.x - pi.x) * (point.y - pi.y) / (pj.y - pi.y) + pi.x)) {
        if (point.y <= pi.y) {
          if (point.y <= pj.y) {
            count++;
          } else {
            final num cross = (pj.x - pi.x) * (point.y - pi.y) - (pj.y - pi.y) * (point.x - pi.x);
            if (cross > 0) {
              count++;
            }
          }
        } else if (point.y <= pj.y) {
          final num cross = (pj.x - pi.x) * (point.y - pi.y) - (pj.y - pi.y) * (point.x - pi.x);
          if (cross < 0) {
            count++;
          }
        }
      }
    }

    if (count % 2 == 1) {
      inside = true;
    }

  }

  return inside;
}