/* attempt to collapse small edges */
static int colelt(pMesh mesh,pSol met,char typchk) {
pTria pt;
pPoint p1,p2;
double ll,ux,uy,uz;
int ier,list[LMAX+2],ilist,k,nc;
char i,i1,i2;
nc = 0;
for (k=1; k<=mesh->nt; k++) {
pt = &mesh->tria[k];
if ( !MS_EOK(pt) || pt->ref < 0 ) continue;
/* check edge length */
pt->flag = 0;
ier = 0;
for (i=0; i<3; i++) {
if ( MS_SIN(pt->tag[i]) ) continue;
i1 = inxt[i];
i2 = iprv[i];
p1 = &mesh->point[pt->v[i1]];
p2 = &mesh->point[pt->v[i2]];
if ( p1->tag & MS_NOM || p2->tag & MS_NOM ) continue;
else if ( MS_SIN(p1->tag) ) continue;
else if ( p1->tag > p2->tag || p1->tag > pt->tag[i] ) continue;
/* check length */
if ( typchk == 1 ) {
ux = p2->c[0] - p1->c[0];
uy = p2->c[1] - p1->c[1];
uz = p2->c[2] - p1->c[2];
ll = ux*ux + uy*uy + uz*uz;
if ( ll > info.hmin*info.hmin ) continue;
}
else {
ll = lenedg(mesh,met,pt->v[i1],pt->v[i2],0);
if ( ll > LSHRT ) continue;
}
/* check if geometry preserved */
ilist = chkcol(mesh,met,k,i,list,typchk);
if ( ilist > 3 ) {
nc += colver(mesh,list,ilist);
break;
}
else if ( ilist == 3 ) {
nc += colver3(mesh,list);
break;
}
else if ( ilist == 2 ) {
nc += colver2(mesh,list);
break;
}
}
}
if ( nc > 0 && (abs(info.imprim) > 5 || info.ddebug) )
fprintf(stdout," %8d vertices removed\n",nc);
return(nc);
}
/* analyze triangles and split or collapse to match gradation */
static int adpcol(pMesh mesh,pSol met) {
pTria pt;
pPoint p1,p2;
double len;
int k,list[LMAX+2],ilist,nc;
char i,i1,i2;
nc = 0;
for (k=1; k<=mesh->nt; k++) {
pt = &mesh->tria[k];
if ( !MS_EOK(pt) || pt->ref < 0 ) continue;
/* check edge length */
pt->flag = 0;
for (i=0; i<3; i++) {
if ( MS_SIN(pt->tag[i]) ) continue;
/* check length */
i1 = inxt[i];
i2 = iprv[i];
p1 = &mesh->point[pt->v[i1]];
p2 = &mesh->point[pt->v[i2]];
if ( p1->tag & MS_NOM || p2->tag & MS_NOM ) continue;
len = lenedg(mesh,met,pt->v[i1],pt->v[i2],0);
if ( len > LOPTS ) continue;
p1 = &mesh->point[pt->v[i1]];
p2 = &mesh->point[pt->v[i2]];
if ( MS_SIN(p1->tag) ) continue;
else if ( p1->tag > p2->tag || p1->tag > pt->tag[i] ) continue;
/* check if geometry preserved */
ilist = chkcol(mesh,met,k,i,list,2);
if ( ilist > 3 ) {
nc += colver(mesh,list,ilist);
break;
}
else if ( ilist == 3 ) {
nc += colver3(mesh,list);
break;
}
else if ( ilist == 2 ) {
nc += colver2(mesh,list);
break;
}
}
}
return(nc);
}
/* collapse edge i of k, i1->i2 */
int litcol(MMG5_pMesh mesh,int k,char i,double kali) {
MMG5_pTria pt,pt0,pt1;
MMG5_pPoint p1,p2;
double kal,ps,cosnold,cosnnew,n0old[3],n0new[3],n1old[3],n1new[3],n00old[3],n00new[3];
int *adja,list[_MMG5_LMAX+2],jel,ip2,l,ilist;
char i1,i2,j,jj,j2,open;
pt0 = &mesh->tria[0];
pt = &mesh->tria[k];
i1 = _MMG5_inxt2[i];
i2 = _MMG5_iprv2[i];
ip2 = pt->v[i2];
/* collect all triangles around vertex i1 */
ilist = boulet(mesh,k,i1,list);
/* check for open ball */
adja = &mesh->adja[3*(k-1)+1];
open = adja[i] == 0;
if ( ilist > 3 ) {
/* check references */
jel = list[1] / 3;
pt1 = &mesh->tria[jel];
if ( abs(pt->ref) != abs(pt1->ref) ) return(0);
/* analyze ball */
for (l=1; l<ilist-1+open; l++) {
jel = list[l] / 3;
j = list[l] % 3;
jj = _MMG5_inxt2[j];
j2 = _MMG5_iprv2[j];
pt1 = &mesh->tria[jel];
/* check normal flipping */
if ( !_MMG5_nortri(mesh,pt1,n1old) ) return(0);
memcpy(pt0,pt1,sizeof(MMG5_Tria));
pt0->v[j] = ip2;
if ( !_MMG5_nortri(mesh,pt0,n1new) ) return(0);
ps = n1new[0]*n1old[0] + n1new[1]*n1old[1] + n1new[2]*n1old[2];
if ( ps < 0.0 ) return(0);
/* keep normals at 1st triangles */
if ( l == 1 && !open ) {
memcpy(n00old,n1old,3*sizeof(double));
memcpy(n00new,n1new,3*sizeof(double));
}
/* check normals deviation */
if ( !(pt1->tag[j2] & MG_GEO) ) {
if ( l > 1 ) {
cosnold = n0old[0]*n1old[0] + n0old[1]*n1old[1] + n0old[2]*n1old[2];
cosnnew = n0new[0]*n1new[0] + n0new[1]*n1new[1] + n0new[2]*n1new[2];
if ( cosnold < _MMG5_ANGEDG ) {
if ( cosnnew < MG_MIN(0.0,cosnold) ) return(0);
}
else if ( cosnnew < _MMG5_ANGEDG ) return(0);
}
memcpy(n0old,n1old,3*sizeof(double));
memcpy(n0new,n1new,3*sizeof(double));
}
/* check quality */
kal = ALPHAD*_MMG5_caltri_iso(mesh,NULL,pt0);
if ( kal < NULKAL ) return(0);
}
/* check angle between 1st and last triangles */
if ( !open ) {
cosnold = n00old[0]*n1old[0] + n00old[1]*n1old[1] + n00old[2]*n1old[2];
cosnnew = n00new[0]*n1new[0] + n00new[1]*n1new[1] + n00new[2]*n1new[2];
if ( cosnold < _MMG5_ANGEDG ) {
if ( cosnnew < MG_MIN(0.0,cosnold) ) return(0);
}
else if ( cosnnew < _MMG5_ANGEDG ) return(0);
/* other reference checks */
jel = list[ilist-1] / 3;
pt = &mesh->tria[jel];
jel = list[ilist-2] / 3;
pt1 = &mesh->tria[jel];
if ( abs(pt->ref) != abs(pt1->ref) ) return(0);
}
return(colver(mesh,list,ilist));
}
/* specific test: no collapse if any interior edge is EDG */
else if ( ilist == 3 ) {
p1 = &mesh->point[pt->v[i1]];
if ( MS_SIN(p1->tag) ) return(0);
else if ( MG_EDG(pt->tag[i2]) && !MG_EDG(pt->tag[i]) ) return(0);
else if ( !MG_EDG(pt->tag[i2]) && MG_EDG(pt->tag[i]) ) return(0);
else if ( MG_EDG(pt->tag[i2]) && MG_EDG(pt->tag[i]) && MG_EDG(pt->tag[i1]) ) return(0);
return(colver3(mesh,list));
}
/* for specific configurations along open ridge */
else if ( ilist == 2 ) {
if ( !open ) return(0);
jel = list[1] / 3;
j = list[1] % 3;
jj = _MMG5_inxt2[j];
pt1 = &mesh->tria[jel];
if ( abs(pt->ref) != abs(pt1->ref) ) return(0);
else if ( !(pt1->tag[jj] & MG_GEO) ) return(0);
p1 = &mesh->point[pt->v[i1]];
p2 = &mesh->point[pt1->v[jj]];
if ( p2->tag > p1->tag || p2->ref != p1->ref ) return(0);
return(colver2(mesh,list));
}
return(0);
}
