/// <summary>
/// Iterator.
/// Circulate around a given vertex and enumerate all incoming halfedges.
/// </summary>
/// <param name="vertexHandle">A handle to a vertex to use as a 'center' vertex.</param>
/// <returns>An Enumerable of HalfEdge handles to be used in loops, etc.</returns>
public IEnumerable <HandleHalfEdge> EnVertexIncomingHalfEdge(HandleVertex vertexHandle)
{
List <HandleHalfEdge> LTmpIncomingHedges = new List <HandleHalfEdge>();
//Get the one outgoing half-edge for the vertex.
HandleHalfEdge currentHedge = _LvertexPtrCont[vertexHandle]._h;
//Remember the index of the first half-edge
int startHedgeIndex = currentHedge;
do
{
if (currentHedge == -1)
{
break;
}
HEdgePtrCont currentHedgeContainer = _LhedgePtrCont[currentHedge];
if (vertexHandle == _LhedgePtrCont[currentHedgeContainer._he]._v)
{
LTmpIncomingHedges.Add(currentHedgeContainer._he);
}
currentHedge = _LhedgePtrCont[currentHedgeContainer._he]._nhe;
} while (currentHedge != startHedgeIndex);
return(LTmpIncomingHedges);
//return _LhedgePtrCont.Where(e => e._v == vertexHandle).AsParallel().Select(e => _LhedgePtrCont[e._he._DataIndex]._he).AsParallel().ToList();
//return (from e in _LhedgePtrCont where e._v == vertexHandle select _LhedgePtrCont[e._he]._he).AsParallel().ToList();
}
/// <summary>
/// For testing only now.
/// </summary>
/// <param name="existingEdge"></param>
/// <param name="fromVert"></param>
/// <param name="toVert"></param>
/// <returns></returns>
private HandleHalfEdge ReuseExistingConnection(HandleEdge existingEdge, HandleVertex fromVert, HandleVertex toVert)
{
// Check half-edge 1 and 2 if one points to the actual face. This is the one we use for our face then. If no one we build a new connection.
HEdgePtrCont hedge1 = _LhedgePtrCont[_LedgePtrCont[existingEdge]._he1];
HEdgePtrCont hedge2 = _LhedgePtrCont[_LedgePtrCont[existingEdge]._he2];
HandleHalfEdge hedgeToUse = new HandleHalfEdge(-1);
if (hedge2._f == -1)
{
// It is hedge 2 that is free. We should use it.
hedgeToUse = _LedgePtrCont[existingEdge]._he2;
}
else if (hedge1._f == -1)
{
// It is hedge 1 that is free. We should use it. Should never happen. TODO: Exception throw?
hedgeToUse = _LedgePtrCont[existingEdge]._he1;
}
else
{
// Neither one of the faces of the existing half-edges was free so we build a new edge.
return(CreateAllNewConnection(fromVert, toVert));
}
// Updating the face pointer.
HEdgePtrCont hedge = _LhedgePtrCont[hedgeToUse];
hedge._f = new HandleFace(_LfacePtrCont.Count - 1);
_LhedgePtrCont[hedgeToUse] = new HEdgePtrCont()
{
_f = hedge._f,
_he = hedge._he,
_nhe = hedge._nhe,
_v = hedge._v,
_vn = hedge._vn,
_vuv = hedge._vuv
};
return(hedgeToUse);
}
/// <summary>
/// Adds a face from the importer to the geometry container
/// </summary>
/// <param name="gf">GeoFace object from the importer</param>
private void AddFace(GeoFace gf)
{
// Add a face container.
_LfacePtrCont.Add(
new FacePtrCont()
{
_h = new HandleHalfEdge()
{
_DataIndex = -1
}
}
);
// Add a face handle.
_LfaceHndl.Add(
new HandleFace()
{
_DataIndex = _LfacePtrCont.Count - 1
}
);
// Insert all the vertices for the face.
List <HandleVertex> LHandleVertsForFace = new List <HandleVertex>();
foreach (float3 vVal in gf._LFVertices)
{
LHandleVertsForFace.Add(
AddVertex(vVal)
);
}
// Insert all the uv coordinates for the face.
List <HandleVertexUV> LHandleUVsForFace = new List <HandleVertexUV>();
foreach (float2 uvVal in gf._UV)
{
_LuvCoordinates.Add(uvVal);
LHandleUVsForFace.Add(new HandleVertexUV()
{
_DataIndex = _LuvCoordinates.Count - 1
});
}
// Build up the half-edge connections for the face
List <HandleHalfEdge> LHandleHEForFace = new List <HandleHalfEdge>();
for (int i = 0; i < LHandleVertsForFace.Count; i++)
{
HandleVertex fromVert = LHandleVertsForFace[i];
HandleVertex toVert = i + 1 < LHandleVertsForFace.Count ? LHandleVertsForFace[i + 1] : LHandleVertsForFace[0];
LHandleHEForFace.Add(
CreateConnection(fromVert, toVert)
);
}
// Loop over all the half-edges for the face and concat them and set the correct uv coordinates.
for (int i = 0; i < LHandleHEForFace.Count; i++)
{
HandleHalfEdge currentHedge = LHandleHEForFace[i];
HEdgePtrCont hedge = _LhedgePtrCont[currentHedge];
HandleHalfEdge nextHedge = i + 1 < LHandleHEForFace.Count ? LHandleHEForFace[i + 1] : LHandleHEForFace[0];
hedge._nhe = nextHedge;
if (LHandleUVsForFace.Count > 0)
{
HandleVertexUV currentUV = i + 1 < LHandleUVsForFace.Count ? LHandleUVsForFace[i + 1] : LHandleUVsForFace[0];
hedge._vuv = currentUV;
}
//_LhedgePtrCont.RemoveAt(currentHedge);
//_LhedgePtrCont.Insert(currentHedge, hedge);
_LhedgePtrCont[currentHedge] = new HEdgePtrCont()
{
_f = hedge._f,
_he = hedge._he,
_nhe = hedge._nhe,
_v = hedge._v,
_vn = hedge._vn,
_vuv = hedge._vuv
};
}
// Set the half-edge the face points to.
FacePtrCont face = _LfacePtrCont[_LfacePtrCont.Count - 1];
face._h = new HandleHalfEdge(LHandleHEForFace.First());
_LfacePtrCont.RemoveAt(_LfacePtrCont.Count - 1);
_LfacePtrCont.Add(face);
}
/// <summary>
/// This method converts a quad based 'Geometry' object to a triangle based one.
/// </summary>
private void TriangulateGeometry()
{
List <HandleFace> LtmpFaces = new List <HandleFace>();
foreach (HandleFace currentFace in _LfaceHndl)
{
// Pruefe zuerst ob man das face triangulaten sollte oder nicht.
if (EnFaceAdjacentHalfEdges(currentFace).Count() == 3)
{
continue;
}
// Hole aktuelles face und merke den index.
FacePtrCont currentFaceCont = _LfacePtrCont[currentFace];
// Merke erste hedge h0.
HandleHalfEdge h0H = currentFaceCont._h;
HEdgePtrCont h0Cont = _LhedgePtrCont[h0H];
// Merke ersten vert v0.
HandleVertex v0H = _LhedgePtrCont[h0Cont._he]._v;
// Merke die letzte hedge im face hl.
//HandleHalfEdge hlH = RetLastHalfEdgeInFaceCw(currentFace);
var temp = EnFaceAdjacentHalfEdges(currentFace);
HandleHalfEdge hlH = temp.ElementAt(temp.Count() - 1);
HEdgePtrCont hlCont = _LhedgePtrCont[hlH];
// Lege zwei neue hedges an und fülle sie korrekt.
int hedgeCount = _LhedgePtrCont.Count;
HandleHalfEdge hedge0H = new HandleHalfEdge()
{
_DataIndex = hedgeCount
};
HandleHalfEdge hedge1H = new HandleHalfEdge()
{
_DataIndex = hedgeCount + 1
};
HandleEdge edgeHNew = new HandleEdge()
{
_DataIndex = _LedgeHndl.Count
};
EdgePtrCont edgeContNew = new EdgePtrCont()
{
_he1 = hedge0H, _he2 = hedge1H
};
HEdgePtrCont newhedge0 = new HEdgePtrCont()
{
_nhe = h0H,
_v = v0H,
_he = hedge1H,
_f = currentFace,
_vn = hlCont._vn,
_vuv = hlCont._vuv
};
// Hole h1 und h2 zum Merken.
HandleHalfEdge h1H = h0Cont._nhe;
HEdgePtrCont h1Cont = _LhedgePtrCont[h1H];
HandleHalfEdge h2H = h1Cont._nhe;
HEdgePtrCont h2Cont = _LhedgePtrCont[h2H];
HEdgePtrCont newhedge1 = new HEdgePtrCont()
{
_nhe = h1Cont._nhe,
_v = h1Cont._v,
_he = hedge0H,
_f = new HandleFace(-1),
_vn = h1Cont._vn,
_vuv = h1Cont._vuv,
};
// Update die jeweiligen next pointer der angrenzenden hedges.
h1Cont._nhe = hedge0H;
hlCont._nhe = hedge1H;
// Lege ein neues face an für das triangle 2.
HandleFace f1H = new HandleFace()
{
_DataIndex = (_LfaceHndl.Count - 1) + LtmpFaces.Count + 1
};
FacePtrCont f1Cont = new FacePtrCont()
{
_fn = currentFaceCont._fn, _h = hlH
};
// Update das neue triangle bezüglich des neuen faces. Dazu erstmal h2 holen noch.
newhedge1._f = f1H;
h2Cont._f = f1H;
hlCont._f = f1H;
// Sichere die Änderungen in den listen.
_LedgeHndl.Add(edgeHNew);
_LedgePtrCont.Add(edgeContNew);
_LhedgePtrCont.Add(newhedge0);
_LhedgePtrCont.Add(newhedge1);
// Speichere das face handle erstmal in tmp faces wegen der iteration.
LtmpFaces.Add(f1H);
_LfacePtrCont.Add(f1Cont);
_LhedgePtrCont[h1H] = new HEdgePtrCont()
{
_f = h1Cont._f,
_he = h1Cont._he,
_nhe = h1Cont._nhe,
_v = h1Cont._v,
_vn = h1Cont._vn,
_vuv = h1Cont._vuv
};
_LhedgePtrCont[h2H] = new HEdgePtrCont()
{
_f = h2Cont._f,
_he = h2Cont._he,
_nhe = h2Cont._nhe,
_v = h2Cont._v,
_vn = h2Cont._vn,
_vuv = h2Cont._vuv
};
_LhedgePtrCont[hlH] = new HEdgePtrCont()
{
_f = hlCont._f,
_he = hlCont._he,
_nhe = hlCont._nhe,
_v = hlCont._v,
_vn = hlCont._vn,
_vuv = hlCont._vuv
};
}
foreach (HandleFace handleFace in LtmpFaces)
{
_LfaceHndl.Add(handleFace);
}
LtmpFaces.Clear();
}
