// ALGORITHMS
private void findIntersections()
{
PointF pol1center, pol2center;
sortPointsClockwise(ref polygon1, out pol1center);
sortPointsClockwise(ref polygon1, out pol2center);
var pol1 = new PolyNode[polygon1.Count + 1];
var pol2 = new PolyNode[polygon2.Count + 1];
polygon1.CopyTo(pol1, 0);
polygon2.CopyTo(pol2, 0);
pol1[polygon1.Count] = pol1.First();
pol2[polygon2.Count] = pol2.First();
for (int i = 0; i < pol1.Count() - 1; ++i)
{
for (int j = 0; j < pol2.Count() - 1; ++j)
{
PointF intersection_point = findIntersection(pol1[i].p, pol1[i + 1].p, pol2[j].p, pol2[j + 1].p);
if (intersection_point.X != -1)
{
PolyNode ip1 = new PolyNode(intersection_point, true);
PolyNode ip2 = new PolyNode(intersection_point, true);
var t1 = polygon1.Find(pol1[i]);
while (t1.Next != null && t1.Next.Value.isIntersection && distance(pol1[i + 1].p, t1.Next.Value.p) > distance(pol1[i + 1].p, ip1.p))
{
t1 = t1.Next;
}
var n1 = polygon1.AddAfter(t1, ip1);
var t2 = polygon2.Find(pol2[j]);
while (t2.Next != null && t2.Next.Value.isIntersection && distance(pol2[j + 1].p, t2.Next.Value.p) > distance(pol2[j + 1].p, ip2.p))
{
t2 = t2.Next;
}
var n2 = polygon2.AddAfter(t2, ip2);
n1.Value.otherNode = n2;
n2.Value.otherNode = n1;
}
}
}
}