/*
* R T _ N U R B _ B E Z I E R
*
* Given a single snurb, if it is in Bezier form,
* duplicate the snurb, and enqueue it on the bezier_hd list.
* If the original snurb is NOT in Bezier form,
* subdivide it a set of snurbs which are,
* each of which are enqueued on the bezier_hd list.
*
* In either case, the original surface remains untouched.
*
* Returns -
* 0 Surface splitting was done.
* 1 Original surface was Bezier, only a copy was done.
*/
int
rt_nurb_bezier(struct bu_list *bezier_hd, const struct face_g_snurb *orig_surf, struct resource *res)
{
struct face_g_snurb *s;
int dir;
struct bu_list todo;
NMG_CK_SNURB(orig_surf);
if ( (dir = rt_bez_check( orig_surf )) == -1) {
s = rt_nurb_scopy( orig_surf, res );
BU_LIST_APPEND( bezier_hd, &s->l );
return 1; /* Was already Bezier, nothing done */
}
BU_LIST_INIT( &todo );
rt_nurb_s_split( &todo, orig_surf, dir, res );
while ( BU_LIST_WHILE( s, face_g_snurb, &todo ) ) {
if ( (dir = rt_bez_check(s)) == -1) {
/* This snurb is now a Bezier */
BU_LIST_DEQUEUE( &s->l );
BU_LIST_APPEND( bezier_hd, &s->l );
} else {
/* Split, and keep going */
BU_LIST_DEQUEUE( &s->l );
rt_nurb_s_split( &todo, s, dir, res );
rt_nurb_free_snurb(s, res);
}
}
return 0; /* Bezier snurbs on bezier_hd list */
}
struct rt_nurb_uv_hit *
rt_nurb_intersect(const struct face_g_snurb *srf, fastf_t *plane1, fastf_t *plane2, double uv_tol, struct resource *res, struct bu_list *plist)
{
struct rt_nurb_uv_hit * h;
struct face_g_snurb * psrf,
* osrf;
int dir,
sub;
point_t vmin,
vmax;
fastf_t u[2],
v[2];
struct bu_list rni_plist;
NMG_CK_SNURB(srf);
h = (struct rt_nurb_uv_hit *) 0;
if (plist == NULL) {
plist = &rni_plist;
BU_LIST_INIT(plist);
}
/* project the surface to a 2 dimensional problem */
/* NOTE that this gives a single snurb back, NOT a list */
psrf = rt_nurb_project_srf(srf, plane2, plane1, res);
psrf->dir = 1;
BU_LIST_APPEND(plist, &psrf->l);
if (RT_G_DEBUG & DEBUG_SPLINE)
rt_nurb_s_print("srf", psrf);
/* This list starts out with only a single snurb, but more may be
* added on as work progresses.
*/
while (BU_LIST_WHILE(psrf, face_g_snurb, plist)) {
int flat;
BU_LIST_DEQUEUE(&psrf->l);
NMG_CK_SNURB(psrf);
sub = 0;
flat = 0;
dir = psrf->dir;
while (!flat) {
fastf_t smin = 0.0, smax = 0.0;
sub++;
dir = (dir == 0)?1:0; /* change direction */
if (RT_G_DEBUG & DEBUG_SPLINE)
rt_nurb_s_print("psrf", psrf);
rt_nurb_pbound(psrf, vmin, vmax);
/* Check for origin to be included in the bounding box */
if (!(vmin[0] <= 0.0 && vmin[1] <= 0.0 &&
vmax[0] >= 0.0 && vmax[1] >= 0.0)) {
if (RT_G_DEBUG & DEBUG_SPLINE)
bu_log("this srf doesn't include the origin\n");
flat = 1;
rt_nurb_free_snurb(psrf, res);
continue;
}
rt_nurb_clip_srf(psrf, dir, &smin, &smax);
if ((smax - smin) > .8) {
struct rt_nurb_uv_hit *hp;
/* Split surf, requeue both sub-surfs at head */
/* New surfs will have same dir as arg, here */
if (RT_G_DEBUG & DEBUG_SPLINE)
bu_log("splitting this surface\n");
rt_nurb_s_split(plist, psrf, dir, res);
rt_nurb_free_snurb(psrf, res);
hp = rt_nurb_intersect(srf, plane1, plane2, uv_tol, res, plist);
return hp;
}
if (smin > 1.0 || smax < 0.0) {
if (RT_G_DEBUG & DEBUG_SPLINE)
bu_log("eliminating this surface (smin=%g, smax=%g)\n", smin, smax);
flat = 1;
rt_nurb_free_snurb(psrf, res);
continue;
}
if (dir == RT_NURB_SPLIT_ROW) {
smin = (1.0 - smin) * psrf->u.knots[0] +
smin * psrf->u.knots[
psrf->u.k_size -1];
smax = (1.0 - smax) * psrf->u.knots[0] +
smax * psrf->u.knots[
psrf->u.k_size -1];
} else {
smin = (1.0 - smin) * psrf->v.knots[0] +
smin * psrf->v.knots[
psrf->v.k_size -1];
smax = (1.0 - smax) * psrf->v.knots[0] +
smax * psrf->v.knots[
psrf->v.k_size -1];
}
osrf = psrf;
psrf = (struct face_g_snurb *) rt_nurb_region_from_srf(
osrf, dir, smin, smax, res);
psrf->dir = dir;
rt_nurb_free_snurb(osrf, res);
if (RT_G_DEBUG & DEBUG_SPLINE) {
bu_log("After call to rt_nurb_region_from_srf() (smin=%g, smax=%g)\n", smin, smax);
rt_nurb_s_print("psrf", psrf);
}
u[0] = psrf->u.knots[0];
u[1] = psrf->u.knots[psrf->u.k_size -1];
v[0] = psrf->v.knots[0];
v[1] = psrf->v.knots[psrf->v.k_size -1];
if ((u[1] - u[0]) < uv_tol && (v[1] - v[0]) < uv_tol) {
struct rt_nurb_uv_hit * hit;
if (RT_G_DEBUG & DEBUG_SPLINE) {
fastf_t p1[4], p2[4];
int coords;
vect_t diff;
coords = RT_NURB_EXTRACT_COORDS(srf->pt_type);
rt_nurb_s_eval(srf, u[0], v[0], p1);
rt_nurb_s_eval(srf, u[1], v[1], p2);
if (RT_NURB_IS_PT_RATIONAL(srf->pt_type)) {
fastf_t inv_w;
inv_w = 1.0 / p1[coords-1];
VSCALE(p1, p1, inv_w);
inv_w = 1.0 / p2[coords-1];
VSCALE(p2, p2, inv_w);
}
VSUB2(diff, p1, p2);
bu_log("Precision of hit point = %g (%f %f %f) <-> (%f %f %f)\n",
MAGNITUDE(diff), V3ARGS(p1), V3ARGS(p2));
}
hit = (struct rt_nurb_uv_hit *) bu_malloc(
sizeof(struct rt_nurb_uv_hit), "hit");
hit->next = (struct rt_nurb_uv_hit *)0;
hit->sub = sub;
hit->u = (u[0] + u[1])/2.0;
hit->v = (v[0] + v[1])/2.0;
if (h == (struct rt_nurb_uv_hit *)0)
h = hit;
else {
hit->next = h;
h = hit;
}
flat = 1;
rt_nurb_free_snurb(psrf, res);
}
if ((u[1] - u[0]) > (v[1] - v[0]))
dir = 1;
else dir = 0;
}
}
return (struct rt_nurb_uv_hit *)h;
}
