/// <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);
HandleHalfEdge hlH = EnFaceAdjacentHalfEdges(currentFace).Last();
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();
}
/// <summary>
/// Iterator.
/// Circulate around all the vertices of a given face handle.
/// </summary>
/// <param name="faceHandle">A handle to a face used as the 'center' face.</param>
/// <returns>An Enumerable of vertex handles to be used in loops, etc.</returns>
public IEnumerable<HandleVertex> EnFaceAdjacentVertices(HandleFace faceHandle)
{
return EnFaceAdjacentHalfEdges(faceHandle).Select(handleHalfEdge => _LhedgePtrCont[handleHalfEdge]._v).AsEnumerable();
}
/// <summary>
/// Iterator.
/// Circulate around all the faces surrounding a specific face.
/// </summary>
/// <param name="faceHandle">A handle to a face used as the 'center' face.</param>
/// <returns>An Enumerable of face handles to be used in loops, etc.</returns>
public IEnumerable<HandleFace> EnFaceAdjacentFaces(HandleFace faceHandle)
{
return EnFaceAdjacentHalfEdges(faceHandle).Select(handleHalfEdge => _LhedgePtrCont[_LhedgePtrCont[handleHalfEdge]._he]._f).AsEnumerable();
}
/// <summary>
/// Iterator.
/// This is a method that retrieves all halfedge handles which belong to a specific face handle.
/// </summary>
/// <param name="faceHandle">A handle to the face to get the half-edges from.</param>
/// <returns>An Enumerable of haldedge pointer containers.</returns>
public IEnumerable<HandleHalfEdge> EnFaceAdjacentHalfEdges(HandleFace faceHandle)
{
int startHedgeIndex = _LfacePtrCont[faceHandle]._h;
int currentIndex = startHedgeIndex;
List<HandleHalfEdge> LHedgeHandles = new List<HandleHalfEdge>();
do
{
LHedgeHandles.Add(new HandleHalfEdge(currentIndex));
if (_LhedgePtrCont[_LhedgePtrCont[currentIndex]._nhe]._f != faceHandle)
break;
currentIndex = _LhedgePtrCont[currentIndex]._nhe;
} while (currentIndex != startHedgeIndex);
return LHedgeHandles.AsEnumerable();
}
/// <summary>
/// This method adds a face normal vector to a list.
/// The vector is calculated for the face which handle the method expects.
/// </summary>
/// <param name="faceHandle">Handle to a face to calculate the normal for.</param>
public void CalcFaceNormal(HandleFace faceHandle)
{
List<HandleVertex> tmpList = EnFaceAdjacentVertices(faceHandle).ToList();
if (tmpList.Count < 3)
return;
var v0 = _LvertexVal[tmpList[0]];
var v1 = _LvertexVal[tmpList[1]];
var v2 = _LvertexVal[tmpList[2]];
float3 c1 = float3.Subtract(v0, v1);
float3 c2 = float3.Subtract(v0, v2);
float3 n = float3.Cross(c1, c2);
_LfaceNormals.Add(float3.NormalizeFast(n));
FacePtrCont fc = _LfacePtrCont[faceHandle];
_LfacePtrCont[faceHandle] = new FacePtrCont()
{
_fn = new HandleFaceNormal(_LfaceNormals.Count - 1),
_h = fc._h
};
}
