public static void SortSites(List <Site> sites)
{
sites.Sort(delegate(Site s0, Site s1) {
int returnValue = Voronoi.CompareByYThenX(s0, s1);
int tempIndex;
if (returnValue == -1)
{
if (s0.siteIndex > s1.SiteIndex)
{
tempIndex = s0.SiteIndex;
s0.SiteIndex = s1.SiteIndex;
s1.SiteIndex = tempIndex;
}
}
else if (returnValue == 1)
{
if (s1.SiteIndex > s0.SiteIndex)
{
tempIndex = s1.SiteIndex;
s1.SiteIndex = s0.SiteIndex;
s0.SiteIndex = tempIndex;
}
}
return(returnValue);
});
}
public int CompareTo(Site s1)
{
int returnValue = Voronoi.CompareByYThenX(this, s1);
int tempIndex;
if (returnValue == -1)
{
if (this.SiteIndex > s1.SiteIndex)
{
tempIndex = this.SiteIndex;
this.SiteIndex = s1.SiteIndex;
s1.SiteIndex = tempIndex;
}
}
else if (returnValue == 1)
{
if (s1.SiteIndex > this.SiteIndex)
{
tempIndex = s1.SiteIndex;
s1.SiteIndex = this.SiteIndex;
this.SiteIndex = tempIndex;
}
}
return(returnValue);
}
/*
* This is the only way to make a Vertex
*
* @param halfedge0
* @param halfedge1
* @return
*
*/
public static Vertex Intersect(Halfedge halfedge0, Halfedge halfedge1)
{
Edge edge, edge0, edge1;
Halfedge halfedge;
float determinant, intersectionX, intersectionY;
bool rightOfSite;
edge0 = halfedge0.edge;
edge1 = halfedge1.edge;
if (edge0 == null || edge1 == null)
{
return(null);
}
if (edge0.RightSite == edge1.RightSite)
{
return(null);
}
determinant = edge0.a * edge1.b - edge0.b * edge1.a;
if (Math.Pow(-1.0, 10) < determinant && determinant < Math.Pow(1.0, -10))
{
// The edges are parallel
return(null);
}
intersectionX = (edge0.c * edge1.b - edge1.c * edge0.b) / determinant;
intersectionY = (edge1.c * edge0.a - edge0.c * edge1.a) / determinant;
if (Voronoi.CompareByYThenX(edge0.RightSite, edge1.RightSite) < 0)
{
halfedge = halfedge0;
edge = edge0;
}
else
{
halfedge = halfedge1;
edge = edge1;
}
rightOfSite = intersectionX >= edge.RightSite.x;
if ((rightOfSite && halfedge.leftRight == LR.LEFT) ||
(!rightOfSite && halfedge.leftRight == LR.RIGHT))
{
return(null);
}
return(Vertex.Create(intersectionX, intersectionY));
}