private static List <KeyValuePair <Vertex, bool> > OutlineVertices(PolyBoundary polyBoundary)
{
var outlineVerts = new List <KeyValuePair <Vertex, bool> >();
var handle = 0;
if (_geometry.DictVertices.Count != 0)
{
handle = _geometry.DictVertices.Count;
}
foreach (var coord in polyBoundary.Points)
{
bool isOldVert;
handle++;
var vert = CreateOrFindVertex(coord, out isOldVert, handle);
outlineVerts.Add(new KeyValuePair <Vertex, bool>(vert, isOldVert));
}
return(outlineVerts);
}
private static IEnumerable <BoundaryEdge> CreateHalfEdgesForBoundary(PolyBoundary outline)
{
var outlineVerts = OutlineVertices(outline);
var boundaryEdges = BoundaryEdges(outlineVerts, outline);
SetPrevAndNextForBoundary(boundaryEdges);
var halfEdgesToUpdate = new List <HalfEdge>();
for (var i = boundaryEdges.Count - 1; i > -1; i--)
{
var bEdge = boundaryEdges[i];
if (!bEdge.IsOriginOldVert)
{
continue; //A half-edge can only exist if its source vertex is an old one.
}
int existingHeHandle;
if (!IsEdgeExisting(bEdge.HalfEdge, boundaryEdges, out existingHeHandle))
{
continue; //Check the target vertex to identify the existing half edge.
}
//If the existing half edge is halfedge.IncidentFace.OuterHalfEdge, replace it.
var face = _geometry.GetFaceByHandle(bEdge.HalfEdge.IncidentFace);
if (face.OuterHalfEdge == bEdge.HalfEdge.Handle)
{
face.OuterHalfEdge = existingHeHandle;
_geometry.ReplaceFace(face);
}
//If the existing half edge is one of the unbounded faces inner half edges, replace it.
var unboundedFace = _geometry.DictFaces[1];
for (var k = 0; k < unboundedFace.InnerHalfEdges.Count; k++)
{
var heHandle = unboundedFace.InnerHalfEdges[k];
if (heHandle != existingHeHandle)
{
continue;
}
var nextHe = _geometry.GetHalfEdgeByHandle(heHandle).NextHalfEdge;
unboundedFace.InnerHalfEdges[k] = nextHe;
_geometry.DictFaces[1] = unboundedFace;
break;
}
var existingHe = _geometry.GetHalfEdgeByHandle(existingHeHandle);
existingHe.NextHalfEdge = bEdge.HalfEdge.NextHalfEdge;
existingHe.PrevHalfEdge = bEdge.HalfEdge.PrevHalfEdge;
existingHe.IncidentFace = bEdge.HalfEdge.IncidentFace;
halfEdgesToUpdate.Add(existingHe);
SetPrevAndNextToExistingHalfEdge(bEdge, existingHeHandle, boundaryEdges, halfEdgesToUpdate);
boundaryEdges.RemoveAt(i);
}
if (halfEdgesToUpdate.Count == 0)
{
return(boundaryEdges);
}
foreach (var he in halfEdgesToUpdate)
{
_geometry.ReplaceHalfEdge(he);
}
return(boundaryEdges);
}
private static List <BoundaryEdge> BoundaryEdges(IList <KeyValuePair <Vertex, bool> > outlineVerts,
PolyBoundary polyBoundary)
{
var faceHandle = new int();
var boundaryEdges = new List <BoundaryEdge>();
var halfEdgeHandle = 0;
if (_geometry.DictHalfEdges.Count != 0)
{
halfEdgeHandle = _geometry.DictHalfEdges.Count;
}
for (var j = 0; j < outlineVerts.Count; j++)
{
var currentVert = outlineVerts[j];
halfEdgeHandle++;
if (!currentVert.Value)
{
//Only necessary for new vertices.
var vert = currentVert.Key;
vert.IncidentHalfEdge = halfEdgeHandle;
_geometry.DictVertices.Add(vert.Handle, vert);
}
var halfEdge = new HalfEdge(halfEdgeHandle, currentVert.Key.Handle);
halfEdgeHandle++;
var twinHalfEdge = new HalfEdge(halfEdgeHandle, outlineVerts[(j + 1) % outlineVerts.Count].Key.Handle,
halfEdge.Handle, 0, 0, 1);
//The unbounded face is always added at first and therefor has 1 as handle.
halfEdge.TwinHalfEdge = twinHalfEdge.Handle;
//Assumption: outlines are processed from outer to inner, therefore faceHandle will never has its default value if "else" is hit.
if (polyBoundary.IsOuter)
{
if (faceHandle == default(int))
{
Face face;
faceHandle = AddFace(halfEdge.Handle, out face);
_geometry.DictFaces.Add(face.Handle, face);
}
}
else
{
if (j == 0)
{
var lastFace = _geometry.DictFaces[_geometry.DictFaces.Keys.Max()];
lastFace.InnerHalfEdges.Add(halfEdge.Handle);
}
faceHandle = _geometry.DictFaces.Last().Value.Handle;
}
halfEdge.IncidentFace = faceHandle;
if (!outlineVerts[j].Value)
{
var unboundFace = _geometry.DictFaces[1];
if (j == 0)
{
unboundFace.InnerHalfEdges.Add(twinHalfEdge.Handle);
_geometry.DictFaces[1] = unboundFace;
}
}
var boundaryEdge = new BoundaryEdge
{
IsOriginOldVert = currentVert.Value,
HalfEdge = halfEdge,
TwinHalfEdge = twinHalfEdge
};
boundaryEdges.Add(boundaryEdge);
}
return(boundaryEdges);
}