private static Vertex AddVertex(WeVertex vtx, RayedMesh mesh)
{
// ReSharper disable once ConvertIfStatementToNullCoalescingExpression
if (vtx.HalfEdgeVertex == null)
{
vtx.HalfEdgeVertex = vtx.FAtInfinity ? mesh.AddRayedVertex(vtx.Pt) : mesh.AddVertex(vtx.Pt);
}
return(vtx.HalfEdgeVertex);
}
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;
}
