private static void CreateSidefaces(Geometry geometry)
{
var unboundedFace = geometry.GetFaceByHandle(1); //The unbounded face is always added first - therefore it will always have 1 as handle.
var frontLoopsStartHalfEdges = unboundedFace.InnerHalfEdges.Take(unboundedFace.InnerHalfEdges.Count / 2).ToList();
var backLoopsStartHalfEdges = unboundedFace.InnerHalfEdges.Skip(unboundedFace.InnerHalfEdges.Count / 2).ToList();
for (var i = 0; i < frontLoopsStartHalfEdges.Count; i++)
{
var frontEdgeLoop = geometry.GetHalfEdgeLoop(frontLoopsStartHalfEdges[i]).ToList();
var backEdgeLoop = geometry.GetHalfEdgeLoopReverse(backLoopsStartHalfEdges[i]).ToList();
var newHalfEdges = new List <HalfEdge>();
var newFaces = new List <Face>();
for (var j = 0; j < frontEdgeLoop.Count; j++)
{
var halfEdgeFront = frontEdgeLoop[j];
var halfEdgeInBack = backEdgeLoop[j];
var backOriginVert = geometry.GetHalfEdgeByHandle(halfEdgeInBack.NextHalfEdge).OriginVertex;
var frontOriginVert = geometry.GetHalfEdgeByHandle(halfEdgeFront.NextHalfEdge).OriginVertex;
var newFromBack = new HalfEdge(geometry.CreateHalfEdgeHandleId())
{
OriginVertex = backOriginVert,
NextHalfEdge = halfEdgeFront.Handle,
PrevHalfEdge = halfEdgeInBack.Handle
};
var newFace = new Face(geometry.CreateFaceHandleId(), newFromBack.Handle);
newFaces.Add(newFace);
geometry.DictFaces.Add(newFace.Handle, newFace);
newFromBack.IncidentFace = newFace.Handle;
var newFromFront = new HalfEdge(geometry.CreateHalfEdgeHandleId())
{
OriginVertex = frontOriginVert,
NextHalfEdge = halfEdgeInBack.Handle,
PrevHalfEdge = halfEdgeFront.Handle,
IncidentFace = newFace.Handle
};
halfEdgeFront.IncidentFace = newFace.Handle;
halfEdgeFront.NextHalfEdge = newFromFront.Handle;
halfEdgeFront.PrevHalfEdge = newFromBack.Handle;
halfEdgeInBack.IncidentFace = newFace.Handle;
halfEdgeInBack.NextHalfEdge = newFromBack.Handle;
halfEdgeInBack.PrevHalfEdge = newFromFront.Handle;
geometry.ReplaceHalfEdge(halfEdgeFront);
geometry.ReplaceHalfEdge(halfEdgeInBack);
newHalfEdges.Add(newFromBack);
newHalfEdges.Add(newFromFront);
}
for (var j = 0; j < newHalfEdges.Count; j++)
{
var current = newHalfEdges[j];
if (j == 0)
{
current.TwinHalfEdge = newHalfEdges.Last().Handle;
}
else if (j == newHalfEdges.Count - 1)
{
current.TwinHalfEdge = newHalfEdges[0].Handle;
}
else if (j % 2 != 0 && j != newHalfEdges.Count - 1) //odd
{
current.TwinHalfEdge = newHalfEdges[j + 1].Handle;
}
else if (j % 2 == 0 && j != 0) //even
{
current.TwinHalfEdge = newHalfEdges[j - 1].Handle;
}
newHalfEdges[j] = current;
geometry.DictHalfEdges.Add(current.Handle, current);
}
foreach (var face in newFaces)
{
geometry.SetFaceNormal(geometry.GetFaceOuterVertices(face.Handle).ToList(), geometry.DictFaces[face.Handle]);
}
}
//Delete unbounded face
geometry.DictFaces.Remove(unboundedFace.Handle);
}
