static ArtSVP *
art_svp_merge_perturbed (const ArtSVP *svp1, const ArtSVP *svp2)
{
ArtVpath *vpath1, *vpath2;
ArtVpath *vpath1_p, *vpath2_p;
ArtSVP *svp1_p, *svp2_p;
ArtSVP *svp_new;
vpath1 = art_vpath_from_svp (svp1);
vpath1_p = art_vpath_perturb (vpath1);
art_free (vpath1);
svp1_p = art_svp_from_vpath (vpath1_p);
art_free (vpath1_p);
vpath2 = art_vpath_from_svp (svp2);
vpath2_p = art_vpath_perturb (vpath2);
art_free (vpath2);
svp2_p = art_svp_from_vpath (vpath2_p);
art_free (vpath2_p);
svp_new = art_svp_merge (svp1_p, svp2_p);
#ifdef VERBOSE
print_ps_svp (svp1_p);
print_ps_svp (svp2_p);
print_ps_svp (svp_new);
#endif
art_free (svp1_p);
art_free (svp2_p);
return svp_new;
}
ArtSVP *
art_svp_minus (const ArtSVP *svp1, const ArtSVP *svp2)
{
ArtSVP *svp2_mod;
ArtSVP *svp3, *svp_new;
ArtSvpWriter *swr;
int i;
svp2_mod = (ArtSVP *) svp2; /* get rid of the const for a while */
/* First invert svp2 to "turn it inside out" */
for (i = 0; i < svp2_mod->n_segs; i++)
svp2_mod->segs[i].dir = !svp2_mod->segs[i].dir;
svp3 = art_svp_merge (svp1, svp2_mod);
swr = art_svp_writer_rewind_new (ART_WIND_RULE_POSITIVE);
art_svp_intersector (svp3, swr);
svp_new = art_svp_writer_rewind_reap (swr);
art_free (svp3); /* shallow free because svp3 contains shared segments */
/* Flip svp2 back to its original state */
for (i = 0; i < svp2_mod->n_segs; i++)
svp2_mod->segs[i].dir = !svp2_mod->segs[i].dir;
return svp_new;
}
/**
* art_svp_intersect: Compute the intersection of two sorted vector paths.
* @svp1: One sorted vector path.
* @svp2: The other sorted vector path.
*
* Computes the intersection of the two argument svp's. Given two
* svp's with winding numbers of 0 and 1 everywhere, the resulting
* winding number will be 1 where both of the argument svp's has a
* winding number 1, 0 otherwise. The result is newly allocated.
*
* Currently, this routine has accuracy problems pending the
* implementation of the new intersector.
*
* Return value: The intersection of @svp1 and @svp2.
**/
ArtSVP *
art_svp_intersect (const ArtSVP *svp1, const ArtSVP *svp2)
{
#ifdef ART_USE_NEW_INTERSECTOR
ArtSVP *svp3, *svp_new;
ArtSvpWriter *swr;
#ifdef ROBIN_DEBUG
dump_svp("art_svp_intersect svp1", svp1);
dump_svp("art_svp_intersect svp2", svp2);
#endif
svp3 = art_svp_merge (svp1, svp2);
swr = art_svp_writer_rewind_new (ART_WIND_RULE_INTERSECT);
art_svp_intersector (svp3, swr);
svp_new = art_svp_writer_rewind_reap (swr);
art_free (svp3); /* shallow free because svp3 contains shared segments */
#ifdef ROBIN_DEBUG
dump_svp("art_svp_intersect svp_new", svp_new);
#endif
return svp_new;
#else
ArtSVP *svp3, *svp4, *svp_new;
svp3 = art_svp_merge_perturbed (svp1, svp2);
svp4 = art_svp_uncross (svp3);
art_svp_free (svp3);
svp_new = art_svp_rewind_uncrossed (svp4, ART_WIND_RULE_INTERSECT);
art_svp_free (svp4);
return svp_new;
#endif
}
/**
* art_svp_diff: Compute the symmetric difference of two sorted vector paths.
* @svp1: One sorted vector path.
* @svp2: The other sorted vector path.
*
* Computes the symmetric of the two argument svp's. Given two svp's
* with winding numbers of 0 and 1 everywhere, the resulting winding
* number will be 1 where either, but not both, of the argument svp's
* has a winding number 1, 0 otherwise. The result is newly allocated.
*
* Currently, this routine has accuracy problems pending the
* implementation of the new intersector.
*
* Return value: The symmetric difference of @svp1 and @svp2.
**/
ArtSVP *
art_svp_diff (const ArtSVP *svp1, const ArtSVP *svp2)
{
#ifdef ART_USE_NEW_INTERSECTOR
ArtSVP *svp3, *svp_new;
ArtSvpWriter *swr;
svp3 = art_svp_merge (svp1, svp2);
swr = art_svp_writer_rewind_new (ART_WIND_RULE_ODDEVEN);
art_svp_intersector (svp3, swr);
svp_new = art_svp_writer_rewind_reap (swr);
art_free (svp3); /* shallow free because svp3 contains shared segments */
return svp_new;
#else
ArtSVP *svp3, *svp4, *svp_new;
svp3 = art_svp_merge_perturbed (svp1, svp2);
svp4 = art_svp_uncross (svp3);
art_svp_free (svp3);
svp_new = art_svp_rewind_uncrossed (svp4, ART_WIND_RULE_ODDEVEN);
art_svp_free (svp4);
return svp_new;
#endif
}
gfxpoly_t* gfxpoly_intersect(gfxpoly_t*poly1, gfxpoly_t*poly2)
{
ArtSvpWriter *swr;
static int counter = 0;
ArtSVP* svp1 = (ArtSVP*)poly1;
ArtSVP* svp2 = (ArtSVP*)poly2;
msg("<verbose> Intersecting two polygons of %d and %d segments", svp1->n_segs, svp2->n_segs);
#ifdef DEBUG
char filename[80];
sprintf(filename, "isvp%d_src1.ps", counter);
write_svp_postscript(filename, svp1);
sprintf(filename, "isvp%d_src2.ps", counter);
write_svp_postscript(filename, svp2);
#endif
ArtSVP* svp3 = art_svp_merge (svp1, svp2);
#ifdef DEBUG
sprintf(filename, "isvp%d_src.ps", counter);
write_svp_postscript(filename, svp3);
#endif
//write_svp_postscript("svp.ps", svp3);
ArtSVP*svp_new = run_intersector(svp3, ART_WIND_RULE_INTERSECT);
art_free (svp3); /* shallow free because svp3 contains shared segments */
#ifdef DEBUG
sprintf(filename, "isvp%d.ps", counter);
write_svp_postscript(filename, svp_new);
#endif
counter++;
//write_svp_postscript("svp_new.ps", svp_new);
return (gfxpoly_t*)svp_new;
}
