void CDelaunay::splice(EdgePointer a, EdgePointer b)
{
EdgePointer alpha, beta, temp;
alpha = (EdgePointer) rot(onext(a));
beta = (EdgePointer) rot(onext(b));
temp = onext(alpha);
onext(alpha) = onext(beta);
onext(beta) = temp;
temp = onext(a);
onext(a) = onext(b);
onext(b) = temp;
}
// Quad-edge manipulation primitives
EdgePointer CDelaunay::makeEdge(SitePointer origin, SitePointer destination)
{
EdgePointer temp, ans;
temp = allocEdge();
ans = temp;
onext(temp) = ans;
orig(temp) = origin;
onext(++temp) = (EdgePointer) (ans + 3);
onext(++temp) = (EdgePointer) (ans + 2);
orig(temp) = destination;
onext(++temp) = (EdgePointer) (ans + 1);
return(ans);
}
EdgePointer CDelaunay::allocEdge()
{
EdgePointer ans;
if (availEdge == NYL) {
ans = nextEdge, nextEdge += 4;
} else {
ans = availEdge, availEdge = onext(availEdge);
}
return(ans);
}
EdgePointer CDelaunay::consolidateEdges()
{
EdgePointer e;
int i,j;
while (availEdge != NYL) {
nextEdge -= 4; e = availEdge; availEdge = onext(availEdge);
if (e==nextEdge) {
continue; // the one deleted was the last one anyway
}
if ((oneBndryEdge&~3) == nextEdge) {
oneBndryEdge = (EdgePointer) (e | (oneBndryEdge&3));
}
for (i=0,j=3; i<4; i++,j=rot(j)) {
onext(e+i) = onext(nextEdge+i);
onext(rot(onext(e+i))) = (EdgePointer) (e+j);
}
}
return nextEdge;
}
void CDelaunay::freeEdge(EdgePointer e)
{
e ^= e & 3;
onext(e) = availEdge;
availEdge = e;
}
Edge_Record Edge_Record::lprev() const {
return onext().sym();
}
