public void setPrev(HalfEdge edge)
{
prev = edge;
}
public void setOpposite(HalfEdge edge)
{
opposite = edge;
edge.opposite = this;
}
public void setNext(HalfEdge edge)
{
next = edge;
}
public int mergeAdjacentFace(HalfEdge hedgeAdj,
Face[] discarded)
{
Face oppFace = hedgeAdj.oppositeFace();
int numDiscarded = 0;
discarded[numDiscarded++] = oppFace;
oppFace.mark = DELETED;
HalfEdge hedgeOpp = hedgeAdj.getOpposite();
HalfEdge hedgeAdjPrev = hedgeAdj.prev;
HalfEdge hedgeAdjNext = hedgeAdj.next;
HalfEdge hedgeOppPrev = hedgeOpp.prev;
HalfEdge hedgeOppNext = hedgeOpp.next;
while (hedgeAdjPrev.oppositeFace() == oppFace)
{
hedgeAdjPrev = hedgeAdjPrev.prev;
hedgeOppNext = hedgeOppNext.next;
}
while (hedgeAdjNext.oppositeFace() == oppFace)
{
hedgeOppPrev = hedgeOppPrev.prev;
hedgeAdjNext = hedgeAdjNext.next;
}
HalfEdge hedge;
for (hedge = hedgeOppNext; hedge != hedgeOppPrev.next; hedge = hedge.next)
{
hedge.face = this;
}
if (hedgeAdj == he0)
{
he0 = hedgeAdjNext;
}
// handle the half edges at the head
Face discardedFace;
discardedFace = connectHalfEdges(hedgeOppPrev, hedgeAdjNext);
if (discardedFace != null)
{
discarded[numDiscarded++] = discardedFace;
}
// handle the half edges at the tail
discardedFace = connectHalfEdges(hedgeAdjPrev, hedgeOppNext);
if (discardedFace != null)
{
discarded[numDiscarded++] = discardedFace;
}
computeNormalAndCentroid();
checkConsistency();
return(numDiscarded);
}
public void checkConsistency()
{
// do a sanity check on the face
HalfEdge hedge = he0;
double maxd = 0;
int numv = 0;
if (numVerts < 3)
{
throw new Exception(
"degenerate face: " + getVertexString());
}
do
{
HalfEdge hedgeOpp = hedge.getOpposite();
if (hedgeOpp == null)
{
throw new Exception(
"face " + getVertexString() + ": " +
"unreflected half edge " + hedge.getVertexString());
}
else if (hedgeOpp.getOpposite() != hedge)
{
throw new Exception(
"face " + getVertexString() + ": " +
"opposite half edge " + hedgeOpp.getVertexString() +
" has opposite " +
hedgeOpp.getOpposite().getVertexString());
}
if (hedgeOpp.head() != hedge.tail() ||
hedge.head() != hedgeOpp.tail())
{
throw new Exception(
"face " + getVertexString() + ": " +
"half edge " + hedge.getVertexString() +
" reflected by " + hedgeOpp.getVertexString());
}
Face oppFace = hedgeOpp.face;
if (oppFace == null)
{
throw new Exception(
"face " + getVertexString() + ": " +
"no face on half edge " + hedgeOpp.getVertexString());
}
else if (oppFace.mark == DELETED)
{
throw new Exception(
"face " + getVertexString() + ": " +
"opposite face " + oppFace.getVertexString() +
" not on hull");
}
double d = Math.Abs(distanceToPlane(hedge.head().pnt));
if (d > maxd)
{
maxd = d;
}
numv++;
hedge = hedge.next;
}while (hedge != he0);
if (numv != numVerts)
{
throw new Exception(
"face " + getVertexString() + " numVerts=" + numVerts + " should be " + numv);
}
}
private bool doAdjacentMerge(Face face, int mergeType)
{
HalfEdge hedge = face.he0;
bool convex = true;
do
{
Face oppFace = hedge.oppositeFace();
bool merge = false;
double dist1;
if (mergeType == NONCONVEX)
{ // then merge faces if they are definitively non-convex
if (oppFaceDistance(hedge) > -tolerance ||
oppFaceDistance(hedge.opposite) > -tolerance)
{
merge = true;
}
}
else // mergeType == NONCONVEX_WRT_LARGER_FACE
{ // merge faces if they are parallel or non-convex
// wrt to the larger face; otherwise, just mark
// the face non-convex for the second pass.
if (face.area > oppFace.area)
{
if ((dist1 = oppFaceDistance(hedge)) > -tolerance)
{
merge = true;
}
else if (oppFaceDistance(hedge.opposite) > -tolerance)
{
convex = false;
}
}
else
{
if (oppFaceDistance(hedge.opposite) > -tolerance)
{
merge = true;
}
else if (oppFaceDistance(hedge) > -tolerance)
{
convex = false;
}
}
}
if (merge)
{
if (debug)
{
Print(
" merging " + face.getVertexString() + " and " +
oppFace.getVertexString());
}
int numd = face.mergeAdjacentFace(hedge, discardedFaces);
for (int i = 0; i < numd; i++)
{
deleteFacePoints(discardedFaces[i], face);
}
if (debug)
{
Print(
" result: " + face.getVertexString());
}
return(true);
}
hedge = hedge.next;
}while (hedge != face.he0);
if (!convex)
{
face.mark = Face.NON_CONVEX;
}
return(false);
}
private double oppFaceDistance(HalfEdge he)
{
return(he.face.distanceToPlane(he.opposite.face.getCentroid()));
}