bool smaller_angle(const point<2>& first_point, const point<2>& p1, const point<2>& p2)
{
if (collinear(first_point, p1, p2))
return (first_point.square_distance(p1) > first_point.square_distance(p2));
return (!ccw(first_point, p1, p2));
}
void polygon::remove_points_with_same_angle(const point<2>& first_point) {
// asumes points are in leftlower order.
int oldn = _n; // num of points before deletion
int hole = 1; // index marked for potential deletion
for (int i = 2; i < oldn; i++) {
if ( collinear(first_point, vec_points[hole], vec_points[i]) ) {
// leave the farthest point
if (first_point.square_distance(vec_points[hole]) < first_point.square_distance(vec_points[i]))
vec_points[hole] = vec_points[i];
_n--;
} else {
hole++;
if (hole != i)
vec_points[hole] = vec_points[i];
}
}
}
bool operator()(const point<2>& p1, const point<2>& p2) {
if (collinear(_reference, p1, p2))
return (_reference.square_distance(p1) > _reference.square_distance(p2));
return (ccw(_reference, p1, p2));
}
