public bool Contains(Vertex2 point, out int wn)
{
wn = 0;
for (int i = 0; i < Count; i++)
{
if (this[i].y <= point.y)
{
// start y <= P.y
if (this[i + 1].y > point.y) // an upward crossing
{
if (PGUtils.LocatePointOnLine(this[i], this[i + 1], point) > 0) // P left of edge
{
++wn; // have a valid up intersect
}
}
}
else
{
// start y > P.y (no test needed)
if (this[i + 1].y <= point.y) // a downward crossing
{
if (PGUtils.LocatePointOnLine(this[i], this[i + 1], point) < 0) // P right of edge
{
--wn; // have a valid down intersect
}
}
}
}
return(wn != 0);
}
public static Polygon RemoveCollinearVertices(Polygon polygon)
{
if (polygon.Count <= 3)
{
return(polygon);
}
var newPolygon = new Polygon();
for (int i = 0; i < polygon.Count; i++)
{
if (PGUtils.LocatePointOnLine(polygon[i - 1], polygon[i + 1], polygon[i]) != 0)
{
newPolygon.Add(polygon[i]);
}
}
return(newPolygon);
}