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#include "config.h"
#include "point.h"
#include "vector.h"
#include "arrays.h"
#include "matrix.h"
#include "eval.h"
#include "object.h"
#include "simplify.h"
#define INFINITE_RADIUS HUGE_VAL
static flt cone_radius = 1.0;
static flt cube_radius = 0.86602540378443859659; /* sqrt(3)/2 */
static flt cylinder_radius = 1.11803398874989490253; /* sqrt(5)/2 */
static flt sphere_radius = 1.0;
static struct point cone_center = { 0.0, 1.0, 0.0 };
static struct point cube_center = { 0.5, 0.5, 0.5 };
static struct point cylinder_center = { 0.0, 0.5, 0.0 };
static struct point sphere_center = { 0, 0, 0 };
static struct point plane_center = { 0, 0, 0 };
static struct point origin = { 0, 0, 0 };
static inline void set_infinite(struct object * t)
{
t->radius = INFINITE_RADIUS;
}
static inline void union_bs(struct object * t1, struct object * t2,
struct object * obj)
{
struct vector c1c2;
flt dd2, rr, rr2, d, alpha;
if (t1->radius >= INFINITE_RADIUS || t2->radius >= INFINITE_RADIUS) {
obj->radius = INFINITE_RADIUS;
return;
}
between(&t1->center, &t2->center, &c1c2);
dd2 = vlength2(&c1c2);
rr = t2->radius - t1->radius;
rr2 = rr * rr;
if (dd2 <= rr2) {
/* take the biggest sphere */
if (t1->radius <= t2->radius) {
obj->center = t2->center;
obj->radius = t2->radius;
set_infinite(t2);
} else {
obj->center = t1->center;
obj->radius = t1->radius;
set_infinite(t1);
}
return;
}
d = sqrt(dd2);
alpha = rr / (2 * d) + 0.5;
point_along(&t1->center, &c1c2, alpha, &obj->center);
obj->radius = (d + t1->radius + t2->radius) / 2;
}
static inline void intersection_bs(struct object * t1, struct object * t2,
struct object * obj)
{
struct vector c1c2;
flt dd2, rr, rr2, rpr, rpr2, diff, d, te1, te2, te3, te4, te, alpha;
if (t1->radius >= INFINITE_RADIUS) {
obj->center = t2->center;
obj->radius = t2->radius;
return;
}
if (t2->radius >= INFINITE_RADIUS) {
obj->center = t1->center;
obj->radius = t1->radius;
return;
}
between(&t1->center, &t2->center, &c1c2);
dd2 = vlength2(&c1c2);
rr = t1->radius - t2->radius;
rr2 = rr * rr;
if (dd2 <= rr2) {
/* take the smallest sphere */
if (t2->radius <= t1->radius) {
obj->center = t2->center;
obj->radius = t2->radius;
set_infinite(t2);
} else {
obj->center = t1->center;
obj->radius = t1->radius;
set_infinite(t1);
}
return;
}
rpr = t1->radius + t2->radius;
rpr2 = rpr * rpr;
if (dd2 > rpr2) {
obj->center = origin;
obj->radius = 0.0;
return;
}
diff = t1->radius * t1->radius - t2->radius * t2->radius;
if (dd2 <= diff) {
obj->center = t2->center;
obj->radius = t2->radius;
set_infinite(t2);
return;
}
if (dd2 <= -diff) {
obj->center = t1->center;
obj->radius = t1->radius;
set_infinite(t1);
return;
}
d = sqrt(dd2);
te1 = t1->radius + d + t2->radius;
te2 = t1->radius + d - t2->radius;
te3 = t2->radius + d - t1->radius;
te4 = t1->radius + t2->radius - d;
te = (sqrt (te1 * te2 * te3 * te4)) / (2 * d);
alpha =
(t1->radius * t1->radius - t2->radius * t2->radius) / (2 * dd2) + 0.5;
point_along(&t1->center, &c1c2, alpha, &obj->center);
obj->radius = te;
}
static inline void difference_bs(struct object * t1, struct object * t2,
struct object * obj)
{
obj->center = t1->center;
obj->radius = t1->radius;
set_infinite(t1);
}
void compute_bounding_spheres(struct object * obj)
{
if (obj->radius >= 0.0) return; /* already computed */
switch (obj->kind) {
case Cone:
apply_to_point(obj->obj2world, &cone_center, &obj->center);
obj->radius = obj->max_scale_applied * cone_radius;
break;
case Cube:
apply_to_point(obj->obj2world, &cube_center, &obj->center);
obj->radius = obj->max_scale_applied * cube_radius;
break;
case Cylinder:
apply_to_point(obj->obj2world, &cylinder_center, &obj->center);
obj->radius = obj->max_scale_applied * cylinder_radius;
break;
case Plane:
obj->center = plane_center;
obj->radius = INFINITE_RADIUS;
break;
case Sphere:
apply_to_point(obj->obj2world, &sphere_center, &obj->center);
obj->radius = obj->max_scale_applied * sphere_radius;
break;
case Union:
compute_bounding_spheres(obj->o1);
compute_bounding_spheres(obj->o2);
union_bs(obj->o1, obj->o2, obj);
break;
case Intersection:
compute_bounding_spheres(obj->o1);
compute_bounding_spheres(obj->o2);
intersection_bs(obj->o1, obj->o2, obj);
break;
case Difference:
compute_bounding_spheres(obj->o1);
compute_bounding_spheres(obj->o2);
difference_bs(obj->o1, obj->o2, obj);
break;
}
}
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