/* Find convex hull vertex to complete triangle (oriented call) */
static RBFNODE *
find_chull_vert(const RBFNODE *rbf0, const RBFNODE *rbf1)
{
FVECT vmid, vejn, vp;
RBFNODE *rbf, *rbfbest = NULL;
double dprod, area2, bestarea2 = FHUGE, bestdprod = -.5;
VSUB(vejn, rbf1->invec, rbf0->invec);
VADD(vmid, rbf0->invec, rbf1->invec);
if (normalize(vejn) == 0 || normalize(vmid) == 0)
return(NULL);
/* XXX exhaustive search */
/* Find triangle with minimum rotation from perpendicular */
for (rbf = dsf_list; rbf != NULL; rbf = rbf->next) {
if ((rbf == rbf0) | (rbf == rbf1))
continue;
tri_orient(vp, rbf0->invec, rbf1->invec, rbf->invec);
if (DOT(vp, vmid) <= FTINY)
continue; /* wrong orientation */
area2 = .25*DOT(vp,vp);
VSUB(vp, rbf->invec, vmid);
dprod = -DOT(vp, vejn);
VSUM(vp, vp, vejn, dprod); /* above guarantees non-zero */
dprod = DOT(vp, vmid) / VLEN(vp);
if (dprod <= bestdprod + FTINY*(1 - 2*(area2 < bestarea2)))
continue; /* found better already */
if (overlaps_tri(rbf0, rbf1, rbf))
continue; /* overlaps another triangle */
rbfbest = rbf;
bestdprod = dprod; /* new one to beat */
bestarea2 = area2;
}
return(rbfbest);
}
/* Determine if vertex order is reversed (inward normal) */
int
is_rev_tri(const FVECT v1, const FVECT v2, const FVECT v3)
{
FVECT tor;
tri_orient(tor, v1, v2, v3);
return(DOT(tor, v2) < 0.);
}
