bool LAB::user::operator!=(const LAB::user& _Rhs) const { return !_equal_to(_Rhs); }
/* recursively visit all the trapezoids */
static int
traverse_polygon (int* visited, boxf* decomp, int size, segment_t* seg, trap_t* tr,
int mcur, int trnum, int from, int flip, int dir)
{
trap_t *t = &tr[trnum];
int mnew;
int v0, v1;
int retval;
int do_switch = FALSE;
if ((trnum <= 0) || visited[trnum])
return size;
visited[trnum] = TRUE;
if ((t->hi.y > t->lo.y) &&
(seg[t->lseg].v0.x == seg[t->lseg].v1.x) &&
(seg[t->rseg].v0.x == seg[t->rseg].v1.x)) {
if (flip) {
decomp[size].LL.x = t->lo.y;
decomp[size].LL.y = -seg[t->rseg].v0.x;
decomp[size].UR.x = t->hi.y;
decomp[size].UR.y = -seg[t->lseg].v0.x;
} else {
decomp[size].LL.x = seg[t->lseg].v0.x;
decomp[size].LL.y = t->lo.y;
decomp[size].UR.x = seg[t->rseg].v0.x;
decomp[size].UR.y = t->hi.y;
}
size++;
}
/* We have much more information available here. */
/* rseg: goes upwards */
/* lseg: goes downwards */
/* Initially assume that dir = TR_FROM_DN (from the left) */
/* Switch v0 and v1 if necessary afterwards */
/* special cases for triangles with cusps at the opposite ends. */
/* take care of this first */
if ((t->u0 <= 0) && (t->u1 <= 0))
{
if ((t->d0 > 0) && (t->d1 > 0)) /* downward opening triangle */
{
v0 = tr[t->d1].lseg;
v1 = t->lseg;
if (from == t->d1)
{
do_switch = TRUE;
mnew = make_new_monotone_poly(mcur, v1, v0);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->d1, trnum, flip, TR_FROM_UP);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->d0, trnum, flip, TR_FROM_UP);
}
else
{
mnew = make_new_monotone_poly(mcur, v0, v1);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->d0, trnum, flip, TR_FROM_UP);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->d1, trnum, flip, TR_FROM_UP);
}
}
else
{
retval = SP_NOSPLIT; /* Just traverse all neighbours */
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->u0, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->u1, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->d0, trnum, flip, TR_FROM_UP);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->d1, trnum, flip, TR_FROM_UP);
}
}
else if ((t->d0 <= 0) && (t->d1 <= 0))
{
if ((t->u0 > 0) && (t->u1 > 0)) /* upward opening triangle */
{
v0 = t->rseg;
v1 = tr[t->u0].rseg;
if (from == t->u1)
{
do_switch = TRUE;
mnew = make_new_monotone_poly(mcur, v1, v0);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->u1, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->u0, trnum, flip, TR_FROM_DN);
}
else
{
mnew = make_new_monotone_poly(mcur, v0, v1);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->u0, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->u1, trnum, flip, TR_FROM_DN);
}
}
else
{
retval = SP_NOSPLIT; /* Just traverse all neighbours */
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->u0, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->u1, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->d0, trnum, flip, TR_FROM_UP);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->d1, trnum, flip, TR_FROM_UP);
}
}
else if ((t->u0 > 0) && (t->u1 > 0))
{
if ((t->d0 > 0) && (t->d1 > 0)) /* downward + upward cusps */
{
v0 = tr[t->d1].lseg;
v1 = tr[t->u0].rseg;
retval = SP_2UP_2DN;
if (((dir == TR_FROM_DN) && (t->d1 == from)) ||
((dir == TR_FROM_UP) && (t->u1 == from)))
{
do_switch = TRUE;
mnew = make_new_monotone_poly(mcur, v1, v0);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->u1, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->d1, trnum, flip, TR_FROM_UP);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->u0, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->d0, trnum, flip, TR_FROM_UP);
}
else
{
mnew = make_new_monotone_poly(mcur, v0, v1);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->u0, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->d0, trnum, flip, TR_FROM_UP);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->u1, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->d1, trnum, flip, TR_FROM_UP);
}
}
else /* only downward cusp */
{
if (_equal_to(&t->lo, &seg[t->lseg].v1))
{
v0 = tr[t->u0].rseg;
v1 = seg[t->lseg].next;
retval = SP_2UP_LEFT;
if ((dir == TR_FROM_UP) && (t->u0 == from))
{
do_switch = TRUE;
mnew = make_new_monotone_poly(mcur, v1, v0);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->u0, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->d0, trnum, flip, TR_FROM_UP);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->u1, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->d1, trnum, flip, TR_FROM_UP);
}
else
{
mnew = make_new_monotone_poly(mcur, v0, v1);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->u1, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->d0, trnum, flip, TR_FROM_UP);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->d1, trnum, flip, TR_FROM_UP);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->u0, trnum, flip, TR_FROM_DN);
}
}
else
{
v0 = t->rseg;
v1 = tr[t->u0].rseg;
retval = SP_2UP_RIGHT;
if ((dir == TR_FROM_UP) && (t->u1 == from))
{
do_switch = TRUE;
mnew = make_new_monotone_poly(mcur, v1, v0);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->u1, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->d1, trnum, flip, TR_FROM_UP);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->d0, trnum, flip, TR_FROM_UP);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->u0, trnum, flip, TR_FROM_DN);
}
else
{
mnew = make_new_monotone_poly(mcur, v0, v1);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->u0, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->d0, trnum, flip, TR_FROM_UP);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->d1, trnum, flip, TR_FROM_UP);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->u1, trnum, flip, TR_FROM_DN);
}
}
}
}
else if ((t->u0 > 0) || (t->u1 > 0)) /* no downward cusp */
{
if ((t->d0 > 0) && (t->d1 > 0)) /* only upward cusp */
{
if (_equal_to(&t->hi, &seg[t->lseg].v0))
{
v0 = tr[t->d1].lseg;
v1 = t->lseg;
retval = SP_2DN_LEFT;
if (!((dir == TR_FROM_DN) && (t->d0 == from)))
{
do_switch = TRUE;
mnew = make_new_monotone_poly(mcur, v1, v0);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->u1, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->d1, trnum, flip, TR_FROM_UP);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->u0, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->d0, trnum, flip, TR_FROM_UP);
}
else
{
mnew = make_new_monotone_poly(mcur, v0, v1);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->d0, trnum, flip, TR_FROM_UP);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->u0, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->u1, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->d1, trnum, flip, TR_FROM_UP);
}
}
else
{
v0 = tr[t->d1].lseg;
v1 = seg[t->rseg].next;
retval = SP_2DN_RIGHT;
if ((dir == TR_FROM_DN) && (t->d1 == from))
{
do_switch = TRUE;
mnew = make_new_monotone_poly(mcur, v1, v0);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->d1, trnum, flip, TR_FROM_UP);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->u1, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->u0, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->d0, trnum, flip, TR_FROM_UP);
}
else
{
mnew = make_new_monotone_poly(mcur, v0, v1);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->u0, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->d0, trnum, flip, TR_FROM_UP);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->u1, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->d1, trnum, flip, TR_FROM_UP);
}
}
}
else /* no cusp */
{
if (_equal_to(&t->hi, &seg[t->lseg].v0) &&
_equal_to(&t->lo, &seg[t->rseg].v0))
{
v0 = t->rseg;
v1 = t->lseg;
retval = SP_SIMPLE_LRDN;
if (dir == TR_FROM_UP)
{
do_switch = TRUE;
mnew = make_new_monotone_poly(mcur, v1, v0);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->u0, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->u1, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->d1, trnum, flip, TR_FROM_UP);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->d0, trnum, flip, TR_FROM_UP);
}
else
{
mnew = make_new_monotone_poly(mcur, v0, v1);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->d1, trnum, flip, TR_FROM_UP);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->d0, trnum, flip, TR_FROM_UP);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->u0, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->u1, trnum, flip, TR_FROM_DN);
}
}
else if (_equal_to(&t->hi, &seg[t->rseg].v1) &&
_equal_to(&t->lo, &seg[t->lseg].v1))
{
v0 = seg[t->rseg].next;
v1 = seg[t->lseg].next;
retval = SP_SIMPLE_LRUP;
if (dir == TR_FROM_UP)
{
do_switch = TRUE;
mnew = make_new_monotone_poly(mcur, v1, v0);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->u0, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->u1, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->d1, trnum, flip, TR_FROM_UP);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->d0, trnum, flip, TR_FROM_UP);
}
else
{
mnew = make_new_monotone_poly(mcur, v0, v1);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->d1, trnum, flip, TR_FROM_UP);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->d0, trnum, flip, TR_FROM_UP);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->u0, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mnew, t->u1, trnum, flip, TR_FROM_DN);
}
}
else /* no split possible */
{
retval = SP_NOSPLIT;
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->u0, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->d0, trnum, flip, TR_FROM_UP);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->u1, trnum, flip, TR_FROM_DN);
size = traverse_polygon (visited, decomp, size, seg, tr, mcur, t->d1, trnum, flip, TR_FROM_UP);
}
}
}
return size;
}
int triangulate_monotone_polygons(
int nvert,
int nmonpoly,
int op[][3])
{
register int i;
point_t ymax, ymin;
int p, vfirst, posmax, posmin, v;
int vcount, processed;
#ifdef DEBUG
for (i = 0; i < nmonpoly; i++)
{
fprintf(stderr, "\n\nPolygon %d: ", i);
vfirst = mchain[mon[i]].vnum;
p = mchain[mon[i]].next;
fprintf (stderr, "%d ", mchain[mon[i]].vnum);
while (mchain[p].vnum != vfirst)
{
fprintf(stderr, "%d ", mchain[p].vnum);
p = mchain[p].next;
}
}
fprintf(stderr, "\n");
#endif
op_idx = 0;
for (i = 0; i < nmonpoly; i++)
{
vcount = 1;
processed = FALSE;
vfirst = mchain[mon[i]].vnum;
ymax = ymin = vert[vfirst].pt;
posmax = posmin = mon[i];
mchain[mon[i]].marked = TRUE;
p = mchain[mon[i]].next;
while ((v = mchain[p].vnum) != vfirst)
{
if (mchain[p].marked)
{
processed = TRUE;
break; /* break from while */
}
else
mchain[p].marked = TRUE;
if (_greater_than(&vert[v].pt, &ymax))
{
ymax = vert[v].pt;
posmax = p;
}
if (_less_than(&vert[v].pt, &ymin))
{
ymin = vert[v].pt;
posmin = p;
}
p = mchain[p].next;
vcount++;
}
if (processed) /* Go to next polygon */
continue;
if (vcount == 3) /* already a triangle */
{
op[op_idx][0] = mchain[p].vnum;
op[op_idx][1] = mchain[mchain[p].next].vnum;
op[op_idx][2] = mchain[mchain[p].prev].vnum;
op_idx++;
}
else /* triangulate the polygon */
{
v = mchain[mchain[posmax].next].vnum;
if (_equal_to(&vert[v].pt, &ymin))
{ /* LHS is a single line */
triangulate_single_polygon(nvert, posmax, TRI_LHS, op);
}
else
triangulate_single_polygon(nvert, posmax, TRI_RHS, op);
}
}
#ifdef DEBUG
for (i = 0; i < op_idx; i++)
fprintf(stderr, "tri #%d: (%d, %d, %d)\n", i, op[i][0], op[i][1],
op[i][2]);
#endif
return op_idx;
}
