private int ClipAgainstEdge(Edge edgeA, Edge edgeB, List <EdgeClip> clipedges)
{
int intersected = 0;
int[] clipstatus = new int[3];
EdgeClip[] alledges = new EdgeClip[3];
for (int i = 0; i < 3; ++i)
{
alledges[i] = new EdgeClip(edgeA, edgeB.Tri.Edges[i]);
clipstatus[i] = alledges[i].Clip();
if ((clipstatus[i] & EdgeClip.COINCIDENT) != 0)
{
mCoincident = alledges[i].Clipped;
}
else if ((clipstatus[i] & EdgeClip.INTERSECTING) != 0)
{
if (clipstatus[i] == EdgeClip.INTERSECTING)
{
clipedges.Insert(0, alledges[i]);
}
else
{
clipedges.Add(alledges[i]);
}
++intersected;
}
}
return(intersected);
}
/*
* returns INVALID if intersections points are the same
* returns INSIDE if clipped triangle inside clipper triangle
* returns CLIPPED if clipped triangles were generated
*/
ClipResult ClipTriangles(Triangle triA, Triangle triB, EdgeClip edge1, EdgeClip edge2, List <Triangle> clipped)
{
Vector3 temp1;
Vector3 temp2;
Triangle tri;
const int ISECTA = 1;
const int ISECTB = 2;
const int ISECTC = 4;
int mask = ISECTA | ISECTB | ISECTC;
Vector3 va;
Vector3 vb;
Vector3 vc;
Vector3 isect1 = edge1.IntersectionPoint;
Vector3 isect2 = edge2.IntersectionPoint;
if (edge1.ClippedEnd == edge2.ClippedStart)
{
va = triB.GetVertex(edge1.ClippedEnd);
vb = triB.GetVertex(edge1.ClippedStart);
vc = triB.GetVertex(edge2.ClippedEnd);
}
else // edge1.EdgeBStart != edge2.EdgeBEnd
{
va = triB.GetVertex(edge1.ClippedStart);
vb = triB.GetVertex(edge1.ClippedEnd);
vc = triB.GetVertex(edge2.ClippedStart);
}
temp1 = isect1 - isect2;
if (temp1.sqrMagnitude <= EPSILON)
{
return(ClipResult.OUTSIDE);
}
temp1 = va - isect1;
temp2 = va - isect2;
if ((temp1.sqrMagnitude > EPSILON) &&
(temp2.sqrMagnitude > EPSILON))
{
mask &= ~ISECTA;
}
temp1 = vb - isect1;
temp2 = vb - isect2;
if ((temp1.sqrMagnitude > EPSILON) &&
(temp2.sqrMagnitude > EPSILON))
{
mask &= ~ISECTB;
}
temp1 = vc - isect1;
temp2 = vc - isect2;
if ((temp1.sqrMagnitude > EPSILON) &&
(temp2.sqrMagnitude > EPSILON))
{
mask &= ~ISECTC;
}
switch (mask)
{
case ISECTA:
tri = new Triangle(vb, isect1, isect2);
if (!triA.Contains(tri))
{
clipped.Add(tri);
}
tri = new Triangle(vc, isect1, isect2);
if (!triA.Contains(tri))
{
clipped.Add(tri);
}
return(ClipResult.CLIPPED);
case ISECTB:
tri = new Triangle(va, isect1, isect2);
if (!triA.Contains(tri))
{
clipped.Add(tri);
}
tri = new Triangle(vc, isect1, isect2);
if (!triA.Contains(tri))
{
clipped.Add(tri);
}
return(ClipResult.CLIPPED);
case ISECTC:
tri = new Triangle(va, isect1, isect2);
if (!triA.Contains(tri))
{
clipped.Add(tri);
}
tri = new Triangle(vb, isect1, isect2);
if (!triA.Contains(tri))
{
clipped.Add(tri);
}
return(ClipResult.CLIPPED);
case ISECTA | ISECTB:
return((triA.Contains(vc) > 0) ?
ClipResult.INSIDE : ClipResult.COINCIDENT);
case ISECTA | ISECTC:
return((triA.Contains(vb) > 0) ?
ClipResult.INSIDE : ClipResult.COINCIDENT);
case ISECTB | ISECTC:
return((triA.Contains(va) > 0) ?
ClipResult.INSIDE : ClipResult.COINCIDENT);
case 0:
tri = new Triangle(va, isect1, isect2);
if (!triA.Contains(tri))
{
clipped.Add(tri);
}
tri = new Triangle(vb, isect1, isect2);
if (!triA.Contains(tri))
{
clipped.Add(tri);
}
tri = new Triangle(vb, vc, isect2);
if (!triA.Contains(tri))
{
clipped.Add(tri);
}
return(ClipResult.CLIPPED);
}
return(ClipResult.OUTSIDE);
}
