polygonPoint static method

bool polygonPoint(
  1. PolygonShape b,
  2. Vector2 point
)

Implementation

static bool polygonPoint(PolygonShape b, Vector2 point) {
  var collision = false;

  // go through each of the vertices, plus the next
  // vertex in the list
  final vertices = b.points;
  var next = 0;
  for (var current = 0; current < vertices.length; current++) {
    // get next vertex in list
    // if we've hit the end, wrap around to 0
    next = current + 1;
    if (next == vertices.length) {
      next = 0;
    }

    // get the PVectors at our current position
    // this makes our if statement a little cleaner
    final vc = vertices[current]; // c for "current"
    final vn = vertices[next]; // n for "next"

    // compare position, flip 'collision' variable
    // back and forth
    if (((vc.y > point.y && vn.y < point.y) ||
            (vc.y < point.y && vn.y > point.y)) &&
        (point.x < (vn.x - vc.x) * (point.y - vc.y) / (vn.y - vc.y) + vc.x)) {
      collision = !collision;
    }
  }
  return collision;
}