private static List <FortuneEdge> AddEdgeAtInfinity(FortunePoly poly)
{
var newList = new List <FortuneEdge>(poly.FortuneEdges.Count + 1);
int iEdge;
for (iEdge = 0; iEdge < poly.FortuneEdges.Count; iEdge++)
{
newList.Add(poly.FortuneEdges[iEdge]);
if (poly.FortuneEdges[iEdge].FRay)
{
var curEdge = poly.FortuneEdges[iEdge];
var iNext = (iEdge + 1) % poly.FortuneEdges.Count;
var nextEdge = poly.FortuneEdges[iNext];
if (nextEdge.FRay)
{
var newEdge = new FortuneEdge
{
VtxStart = curEdge.VtxEnd,
VtxEnd = nextEdge.VtxEnd
};
newList.Add(newEdge);
break;
}
}
}
newList.AddRange(poly.FortuneEdges.Skip(iEdge + 1));
return(newList);
}
private static void ProcessPolygonEdges(FortunePoly poly, RayedMesh mesh)
{
poly.SortEdges();
var edges = AddEdgeAtInfinity(poly);
WeVertex vtxNext;
// If this poly is a rayed polygon then we need an extra spot in the vertex array for the
// edge at infinity which HalfEdge needs but isn't present in the FortunePolygon.
var polyVertices = new Vertex[edges.Count];
// We have to prime the pump here
if (edges[0].VtxStart == edges[1].VtxStart ||
edges[0].VtxStart == edges[1].VtxEnd)
{
vtxNext = edges[0].VtxStart;
polyVertices[0] = AddVertex(edges[0].VtxEnd, mesh);
}
else
{
vtxNext = edges[0].VtxEnd;
polyVertices[0] = AddVertex(edges[0].VtxStart, mesh);
}
// We skip the first edge since it's already been added in the pump priming above
for (var ivtx = 1; ivtx < edges.Count; ivtx++)
{
var edge = edges[ivtx];
// Add in the leading vertex for this edge
polyVertices[ivtx] = AddVertex(vtxNext, mesh);
if (!edge.FZeroLength())
{
// What about when we traverse this edge from the other direction?
// We don't want to add one vertex going CW and another going CCW.
// I think maybe we have to check if the end or start has already
// been inserted and use that vertex if so. Still - won't that fail
// if there are more than one zero length edge converging?
// TODO: think about this
vtxNext = edge.VtxStart == vtxNext ? edge.VtxEnd : edge.VtxStart;
}
}
// Now add the Polygon
var newFace = mesh.AddFace(polyVertices);
// ReSharper disable once PossibleNullReferenceException
// ReSharper disable once SuspiciousTypeConversion.Global
(newFace as IVoronoi).VoronoiPoint = poly.VoronoiPoint;
}
