void gts_write_triangle (GtsTriangle * t,
GtsPoint * o,
FILE * fptr)
{
gdouble xo = o ? o->x : 0.0;
gdouble yo = o ? o->y : 0.0;
gdouble zo = o ? o->z : 0.0;
g_return_if_fail (t != NULL && fptr != NULL);
fprintf (fptr, "(hdefine geometry \"t%d\" { =\n", id (t));
fprintf (fptr, "OFF 3 1 0\n"
"%g %g %g\n%g %g %g\n%g %g %g\n3 0 1 2\n})\n"
"(geometry \"t%d\" { : \"t%d\"})\n"
"(normalization \"t%d\" none)\n",
GTS_POINT (GTS_SEGMENT (t->e1)->v1)->x - xo,
GTS_POINT (GTS_SEGMENT (t->e1)->v1)->y - yo,
GTS_POINT (GTS_SEGMENT (t->e1)->v1)->z - zo,
GTS_POINT (GTS_SEGMENT (t->e1)->v2)->x - xo,
GTS_POINT (GTS_SEGMENT (t->e1)->v2)->y - yo,
GTS_POINT (GTS_SEGMENT (t->e1)->v2)->z - zo,
GTS_POINT (gts_triangle_vertex (t))->x - xo,
GTS_POINT (gts_triangle_vertex (t))->y - yo,
GTS_POINT (gts_triangle_vertex (t))->z - zo,
id (t), id (t), id (t));
}
static GtsVertex * triangle_use_vertices (GtsTriangle * t,
GtsVertex * A,
GtsVertex * B)
{
GtsVertex
* v1 = GTS_SEGMENT (t->e1)->v1,
* v2 = GTS_SEGMENT (t->e1)->v2,
* v3 = gts_triangle_vertex (t);
if (v1 == A) {
if (v2 == B)
return v3;
g_assert (v3 == B);
return v2;
}
if (v2 == A) {
if (v1 == B)
return v3;
g_assert (v3 == B);
return v1;
}
if (v3 == A) {
if (v1 == B)
return v2;
g_assert (v2 == B);
return v1;
}
g_assert_not_reached ();
return NULL;
}
/**
* gts_triangle_interpolate_height:
* @t: a #GtsTriangle.
* @p: a #GtsPoint.
*
* Fills the z-coordinate of point @p belonging to the plane
* projection of triangle @t with the linearly interpolated value of
* the z-coordinates of the vertices of @t.
*/
void gts_triangle_interpolate_height (GtsTriangle * t, GtsPoint * p)
{
GtsPoint * p1, * p2, * p3;
gdouble x1, x2, y1, y2, det;
g_return_if_fail (t != NULL);
g_return_if_fail (p != NULL);
p1 = GTS_POINT (GTS_SEGMENT (t->e1)->v1);
p2 = GTS_POINT (GTS_SEGMENT (t->e1)->v2);
p3 = GTS_POINT (gts_triangle_vertex (t));
x1 = p2->x - p1->x;
y1 = p2->y - p1->y;
x2 = p3->x - p1->x;
y2 = p3->y - p1->y;
det = x1*y2 - x2*y1;
if (det == 0.)
p->z = (p1->z + p2->z + p3->z)/3.;
else {
gdouble x = p->x - p1->x;
gdouble y = p->y - p1->y;
gdouble a = (x*y2 - y*x2)/det;
gdouble b = (y*x1 - x*y1)/det;
p->z = (1. - a - b)*p1->z + a*p2->z + b*p3->z;
}
}
/**
* gts_bbox_triangle:
* @klass: a #GtsBBoxClass.
* @t: a #GtsTriangle.
*
* Returns: a new #GtsBBox bounding box of @t.
*/
GtsBBox * gts_bbox_triangle (GtsBBoxClass * klass,
GtsTriangle * t)
{
GtsBBox * bbox;
GtsPoint * p;
g_return_val_if_fail (t != NULL, NULL);
g_return_val_if_fail (klass != NULL, NULL);
p = GTS_POINT (GTS_SEGMENT (t->e1)->v1);
bbox = gts_bbox_new (klass, t, p->x, p->y, p->z, p->x, p->y, p->z);
p = GTS_POINT (GTS_SEGMENT (t->e1)->v2);
if (p->x > bbox->x2) bbox->x2 = p->x;
if (p->x < bbox->x1) bbox->x1 = p->x;
if (p->y > bbox->y2) bbox->y2 = p->y;
if (p->y < bbox->y1) bbox->y1 = p->y;
if (p->z > bbox->z2) bbox->z2 = p->z;
if (p->z < bbox->z1) bbox->z1 = p->z;
p = GTS_POINT (gts_triangle_vertex (t));
if (p->x > bbox->x2) bbox->x2 = p->x;
if (p->x < bbox->x1) bbox->x1 = p->x;
if (p->y > bbox->y2) bbox->y2 = p->y;
if (p->y < bbox->y1) bbox->y1 = p->y;
if (p->z > bbox->z2) bbox->z2 = p->z;
if (p->z < bbox->z1) bbox->z1 = p->z;
return bbox;
}
/**
* gts_triangle_perimeter:
* @t: a #GtsTriangle.
*
* Returns: the perimeter of the triangle @t.
*/
gdouble gts_triangle_perimeter (GtsTriangle * t)
{
GtsVertex * v;
g_return_val_if_fail (t != NULL, 0.0);
v = gts_triangle_vertex (t);
return
gts_point_distance (GTS_POINT (GTS_SEGMENT (t->e1)->v1),
GTS_POINT (GTS_SEGMENT (t->e1)->v2)) +
gts_point_distance (GTS_POINT (GTS_SEGMENT (t->e1)->v1),
GTS_POINT (v)) +
gts_point_distance (GTS_POINT (GTS_SEGMENT (t->e1)->v2),
GTS_POINT (v));
}
static void triangle_plane (GtsTriangle * f, GtsVector p)
{
GtsPoint * v1, * v2, * v3;
gdouble x1, x2, y1, y2, det;
v1 = GTS_POINT (GTS_SEGMENT (f->e1)->v1);
v2 = GTS_POINT (GTS_SEGMENT (f->e1)->v2);
v3 = GTS_POINT (gts_triangle_vertex (f));
x1 = v2->x - v1->x;
y1 = v2->y - v1->y;
x2 = v3->x - v1->x;
y2 = v3->y - v1->y;
det = x1*y2 - x2*y1;
g_assert (det != 0.);
p[0] = (y2*(v2->z - v1->z) - y1*(v3->z - v1->z))/det;
p[1] = (-x2*(v2->z - v1->z) + x1*(v3->z - v1->z))/det;
p[2] = ((- v1->x*y2 + v1->y*x2)*(v2->z - v1->z) +
(- v1->y*x1 + v1->x*y1)*(v3->z - v1->z))/det + v1->z;
}
/**
* gts_bbox_overlaps_triangle:
* @bb: a #GtsBBox.
* @t: a #GtsTriangle.
*
* This is a wrapper around the fast overlap test of Tomas
* Akenine-Moller (http://www.cs.lth.se/home/Tomas_Akenine_Moller/).
*
* Returns: %TRUE if @bb overlaps with @t, %FALSE otherwise.
*/
gboolean gts_bbox_overlaps_triangle (GtsBBox * bb, GtsTriangle * t)
{
double bc[3], bh[3], tv[3][3];
GtsPoint * p1, * p2, * p3;
g_return_val_if_fail (bb != NULL, FALSE);
g_return_val_if_fail (t != NULL, FALSE);
bc[0] = (bb->x2 + bb->x1)/2.;
bh[0] = (bb->x2 - bb->x1)/2.;
bc[1] = (bb->y2 + bb->y1)/2.;
bh[1] = (bb->y2 - bb->y1)/2.;
bc[2] = (bb->z2 + bb->z1)/2.;
bh[2] = (bb->z2 - bb->z1)/2.;
p1 = GTS_POINT (GTS_SEGMENT (t->e1)->v1);
p2 = GTS_POINT (GTS_SEGMENT (t->e1)->v2);
p3 = GTS_POINT (gts_triangle_vertex (t));
tv[0][0] = p1->x; tv[0][1] = p1->y; tv[0][2] = p1->z;
tv[1][0] = p2->x; tv[1][1] = p2->y; tv[1][2] = p2->z;
tv[2][0] = p3->x; tv[2][1] = p3->y; tv[2][2] = p3->z;
return triBoxOverlap (bc, bh, tv);
}
/* stripe - Turns the input surface into triangle strips and outputs a
Geomview representation of the result. */
int main (int argc, char * argv[])
{
GtsSurface * s;
GSList * strips = NULL, * i;
gboolean verbose = FALSE;
int c = 0;
GtsFile * fp;
/* parse options using getopt */
while (c != EOF) {
#ifdef HAVE_GETOPT_LONG
static struct option long_options[] = {
{"help", no_argument, NULL, 'h'},
{"verbose", no_argument, NULL, 'v'}
};
int option_index = 0;
switch ((c = getopt_long (argc, argv, "hv",
long_options, &option_index))) {
#else /* not HAVE_GETOPT_LONG */
switch ((c = getopt (argc, argv, "hv"))) {
#endif /* not HAVE_GETOPT_LONG */
case 'v': /* verbose */
verbose = TRUE;
break;
case 'h': /* help */
fprintf (stderr,
"Usage: stripe [OPTION] < FILE\n"
"Turns the input surface into triangle strips and outputs a\n"
"Geomview representation of the result.\n"
"\n"
" -v --verbose print statistics about the surface and strips\n"
" -h --help display this help and exit\n"
"\n"
"Report bugs to %s\n",
GTS_MAINTAINER);
return 0; /* success */
break;
case '?': /* wrong options */
fprintf (stderr, "Try `stripe --help' for more information.\n");
return 1; /* failure */
}
}
/* read surface in */
s = gts_surface_new (gts_surface_class (),
gts_face_class (),
gts_edge_class (),
gts_vertex_class ());
fp = gts_file_new (stdin);
if (gts_surface_read (s, fp)) {
fputs ("stripe: file on standard input is not a valid GTS file\n",
stderr);
fprintf (stderr, "stdin:%d:%d: %s\n", fp->line, fp->pos, fp->error);
return 1; /* failure */
}
gts_file_destroy (fp);
if (verbose)
gts_surface_print_stats (s, stderr);
strips = gts_surface_strip (s);
/* if verbose on print stats */
if (verbose) {
GtsRange l;
gts_range_init (&l);
i = strips;
while (i) {
gts_range_add_value (&l, g_slist_length (i->data));
i = i->next;
}
gts_range_update (&l);
fprintf (stderr, "# Strips: %d\n# length : ", l.n);
gts_range_print (&l, stderr);
fputc ('\n', stderr);
}
puts ("LIST {\n");
i = strips;
while (i) {
GList * j = i->data;
GtsTriangle * oldt = NULL;
GtsColor c;
c.r = rand ()/(gdouble) RAND_MAX;
c.g = rand ()/(gdouble) RAND_MAX;
c.b = rand ()/(gdouble) RAND_MAX;
while (j) {
GtsTriangle * t = j->data;
GtsPoint
* p1 = GTS_POINT (GTS_SEGMENT (t->e1)->v1),
* p2 = GTS_POINT (GTS_SEGMENT (t->e1)->v2),
* p3 = GTS_POINT (gts_triangle_vertex (t));
printf ("OFF 3 1 3\n%g %g %g\n%g %g %g\n%g %g %g\n3 0 1 2 %g %g %g\n",
p1->x, p1->y, p1->z,
p2->x, p2->y, p2->z,
p3->x, p3->y, p3->z,
c.r, c.g, c.b);
if (oldt) {
GtsSegment * cs = GTS_SEGMENT (gts_triangles_common_edge (t, oldt));
GtsPoint
* op1 = GTS_POINT (GTS_SEGMENT (oldt->e1)->v1),
* op2 = GTS_POINT (GTS_SEGMENT (oldt->e1)->v2),
* op3 = GTS_POINT (gts_triangle_vertex (oldt));
printf ("VECT 1 3 0 3 0 %g %g %g %g %g %g %g %g %g\n",
(op1->x + op2->x + op3->x)/3.,
(op1->y + op2->y + op3->y)/3.,
(op1->z + op2->z + op3->z)/3.,
(GTS_POINT (cs->v1)->x + GTS_POINT (cs->v2)->x)/2.,
(GTS_POINT (cs->v1)->y + GTS_POINT (cs->v2)->y)/2.,
(GTS_POINT (cs->v1)->z + GTS_POINT (cs->v2)->z)/2.,
(p1->x + p2->x + p3->x)/3.,
(p1->y + p2->y + p3->y)/3.,
(p1->z + p2->z + p3->z)/3.);
}
oldt = t;
j = j->next;
}
i = i->next;
}
puts ("}\n");
return 0; /* success */
}
