#include <float.h>
#include "geom.h"
+#define SPHERE(ptr) ((Sphere*)ptr)
+#define AABOX(ptr) ((AABox*)ptr)
+#define BOX(ptr) ((Box*)ptr)
+#define PLANE(ptr) ((Plane*)ptr)
+
+GeomObject::GeomObject()
+{
+ type = GOBJ_UNKNOWN;
+}
+
GeomObject::~GeomObject()
{
}
Sphere::Sphere()
{
+ type = GOBJ_SPHERE;
radius = 1.0;
}
Sphere::Sphere(const Vec3 ¢, float radius)
: center(cent)
{
+ type = GOBJ_SPHERE;
this->radius = radius;
}
-GeomObjectType Sphere::get_type() const
-{
- return GOBJ_SPHERE;
-}
-
-void Sphere::set_union(const GeomObject *obj1, const GeomObject *obj2)
-{
- if(obj1->get_type() != GOBJ_SPHERE || obj2->get_type() != GOBJ_SPHERE) {
- fprintf(stderr, "Sphere::set_union: arguments must be spheres");
- return;
- }
- const Sphere *sph1 = (const Sphere*)obj1;
- const Sphere *sph2 = (const Sphere*)obj2;
-
- float dist = length(sph1->center - sph2->center);
- float surf_dist = dist - (sph1->radius + sph2->radius);
- float d1 = sph1->radius + surf_dist / 2.0;
- float d2 = sph2->radius + surf_dist / 2.0;
- float t = d1 / (d1 + d2);
-
- if(t < 0.0) t = 0.0;
- if(t > 1.0) t = 1.0;
-
- center = sph1->center * t + sph2->center * (1.0 - t);
- radius = std::max(dist * t + sph2->radius, dist * (1.0f - t) + sph1->radius);
-}
-
-void Sphere::set_intersection(const GeomObject *obj1, const GeomObject *obj2)
-{
- fprintf(stderr, "Sphere::intersection undefined\n");
-}
-
bool Sphere::intersect(const Ray &ray, HitPoint *hit) const
{
float a = dot(ray.dir, ray.dir);
float Sphere::distance(const Vec3 &v) const
{
+ return std::max(length(v - center) - radius, 0.0f);
+}
+
+float Sphere::signed_distance(const Vec3 &v) const
+{
return length(v - center) - radius;
}
AABox::AABox()
{
+ type = GOBJ_AABOX;
}
AABox::AABox(const Vec3 &vmin, const Vec3 &vmax)
: min(vmin), max(vmax)
{
+ type = GOBJ_AABOX;
}
-GeomObjectType AABox::get_type() const
+Vec3 AABox::get_corner(int idx) const
{
- return GOBJ_AABOX;
-}
-
-void AABox::set_union(const GeomObject *obj1, const GeomObject *obj2)
-{
- if(obj1->get_type() != GOBJ_AABOX || obj2->get_type() != GOBJ_AABOX) {
- fprintf(stderr, "AABox::set_union: arguments must be AABoxes too\n");
- return;
- }
- const AABox *box1 = (const AABox*)obj1;
- const AABox *box2 = (const AABox*)obj2;
-
- min.x = std::min(box1->min.x, box2->min.x);
- min.y = std::min(box1->min.y, box2->min.y);
- min.z = std::min(box1->min.z, box2->min.z);
-
- max.x = std::max(box1->max.x, box2->max.x);
- max.y = std::max(box1->max.y, box2->max.y);
- max.z = std::max(box1->max.z, box2->max.z);
-}
-
-void AABox::set_intersection(const GeomObject *obj1, const GeomObject *obj2)
-{
- if(obj1->get_type() != GOBJ_AABOX || obj2->get_type() != GOBJ_AABOX) {
- fprintf(stderr, "AABox::set_intersection: arguments must be AABoxes too\n");
- return;
- }
- const AABox *box1 = (const AABox*)obj1;
- const AABox *box2 = (const AABox*)obj2;
-
- for(int i=0; i<3; i++) {
- min[i] = std::max(box1->min[i], box2->min[i]);
- max[i] = std::min(box1->max[i], box2->max[i]);
-
- if(max[i] < min[i]) {
- max[i] = min[i];
- }
- }
+ static const Vec3 v[] = {
+ Vec3(-0.5, -0.5, -0.5), Vec3(0.5, -0.5, -0.5), Vec3(0.5, -0.5, 0.5), Vec3(-0.5, -0.5, 0.5),
+ Vec3(-0.5, 0.5, -0.5), Vec3(0.5, 0.5, -0.5), Vec3(0.5, 0.5, 0.5), Vec3(-0.5, 0.5, 0.5)
+ };
+ return v[idx] * Vec3(max - min);
}
bool AABox::intersect(const Ray &ray, HitPoint *hit) const
return 0.0; // TODO
}
+float AABox::signed_distance(const Vec3 &v) const
+{
+ return 0.0; // TODO
+}
+
+Box::Box()
+{
+}
+
+Box::Box(const Vec3 &min, const Vec3 &max)
+ : AABox(min, max)
+{
+}
+
+// XXX all this shit is completely untested
+Box::Box(const Vec3 &pos, const Vec3 &vi, const Vec3 &vj, const Vec3 &vk)
+{
+ float ilen = length(vi);
+ float jlen = length(vj);
+ float klen = length(vk);
+
+ min = Vec3(-ilen, -jlen, -klen);
+ max = Vec3(ilen, jlen, klen);
+
+ float si = ilen == 0.0 ? 1.0 : 1.0 / ilen;
+ float sj = jlen == 0.0 ? 1.0 : 1.0 / jlen;
+ float sk = klen == 0.0 ? 1.0 : 1.0 / klen;
+
+ xform = Mat4(vi * si, vj * sj, vk * sk);
+ xform.translate(pos);
+}
+
+Box::Box(const Vec3 *varr, int vcount)
+{
+ calc_bounding_aabox(this, varr, vcount);
+}
+
+Vec3 Box::get_corner(int idx) const
+{
+ static const Vec3 v[] = {
+ Vec3(-0.5, -0.5, -0.5), Vec3(0.5, -0.5, -0.5), Vec3(0.5, -0.5, 0.5), Vec3(-0.5, -0.5, 0.5),
+ Vec3(-0.5, 0.5, -0.5), Vec3(0.5, 0.5, -0.5), Vec3(0.5, 0.5, 0.5), Vec3(-0.5, 0.5, 0.5)
+ };
+
+ return xform * (v[idx] * Vec3(max - min));
+}
+
+bool Box::intersect(const Ray &ray, HitPoint *hit) const
+{
+ Mat4 inv_xform = inverse(xform);
+ Mat4 dir_inv_xform = inv_xform.upper3x3();
+ Mat4 dir_xform = transpose(dir_inv_xform);
+ Ray local_ray = Ray(inv_xform * ray.origin, dir_inv_xform * ray.dir);
+
+ bool res = AABox::intersect(local_ray, hit);
+ if(!res || !hit) return res;
+
+ hit->pos = xform * hit->pos;
+ hit->normal = dir_xform * hit->normal;
+ hit->local_ray = local_ray;
+ hit->ray = ray;
+ return true;
+}
+
+bool Box::contains(const Vec3 &pt) const
+{
+ // XXX is it faster to extract 6 planes and do dot products? sounds marginal
+ return AABox::contains(inverse(xform) * pt);
+}
+
+float Box::distance(const Vec3 &v) const
+{
+ return 0.0f; // TODO
+}
+
+float Box::signed_distance(const Vec3 &v) const
+{
+ return 0.0f; // TODO
+}
Plane::Plane()
: normal(0.0, 1.0, 0.0)
pt = this->normal * dist;
}
-GeomObjectType Plane::get_type() const
-{
- return GOBJ_PLANE;
-}
-
-void Plane::set_union(const GeomObject *obj1, const GeomObject *obj2)
-{
- fprintf(stderr, "Plane::set_union undefined\n");
-}
-
-void Plane::set_intersection(const GeomObject *obj1, const GeomObject *obj2)
-{
- fprintf(stderr, "Plane::set_intersection undefined\n");
-}
-
bool Plane::intersect(const Ray &ray, HitPoint *hit) const
{
float ndotdir = dot(normal, ray.dir);
float Plane::distance(const Vec3 &v) const
{
+ return std::max(dot(v - pt, normal), 0.0f);
+}
+
+float Plane::signed_distance(const Vec3 &v) const
+{
return dot(v - pt, normal);
}
+
+
+Disc::Disc()
+{
+ radius = 1.0;
+}
+
+Disc::Disc(const Vec3 &pt, const Vec3 &normal, float rad)
+ : Plane(pt, normal)
+{
+ radius = rad;
+}
+
+Disc::Disc(const Vec3 &normal, float dist, float rad)
+ : Plane(normal, dist)
+{
+ radius = rad;
+}
+
+bool Disc::intersect(const Ray &ray, HitPoint *hit) const
+{
+ HitPoint phit;
+ if(Plane::intersect(ray, &phit)) {
+ if(length_sq(phit.pos - pt) <= radius * radius) {
+ *hit = phit;
+ return true;
+ }
+ }
+ return false;
+}
+
+bool Disc::contains(const Vec3 &pt) const
+{
+ Vec3 pj = proj_point_plane(pt, *this);
+ return length_sq(pj - this->pt) <= radius * radius;
+}
+
+float Disc::distance(const Vec3 &v) const
+{
+ return 0.0; // TODO
+}
+
+float Disc::signed_distance(const Vec3 &v) const
+{
+ return 0.0; // TODO
+}
+
+
+Vec3 proj_point_plane(const Vec3 &pt, const Plane &plane)
+{
+ float dist = plane.signed_distance(pt);
+ return pt - plane.normal * dist;
+}
+
+// ---- bounding sphere calculations ----
+
+bool calc_bounding_sphere(Sphere *sph, const GeomObject *obj)
+{
+ switch(obj->type) {
+ case GOBJ_SPHERE:
+ *sph = *(Sphere*)obj;
+ break;
+
+ case GOBJ_AABOX:
+ sph->center = (AABOX(obj)->min + AABOX(obj)->max) * 0.5;
+ sph->radius = length(AABOX(obj)->max - AABOX(obj)->min) * 0.5;
+ break;
+
+ case GOBJ_BOX:
+ sph->center = (BOX(obj)->min + BOX(obj)->max) * 0.5 + BOX(obj)->xform.get_translation();
+ sph->radius = length(BOX(obj)->max - BOX(obj)->min) * 0.5;
+ break;
+
+ case GOBJ_PLANE:
+ default:
+ return false;
+ }
+ return true;
+}
+
+bool calc_bounding_sphere(Sphere *sph, const GeomObject *a, const GeomObject *b)
+{
+ Sphere bsa, bsb;
+
+ if(!calc_bounding_sphere(&bsa, a) || !calc_bounding_sphere(&bsb, b)) {
+ return false;
+ }
+
+ float dist = length(bsa.center - bsb.center);
+ float surf_dist = dist - (bsa.radius + bsb.radius);
+ float d1 = bsa.radius + surf_dist / 2.0;
+ float d2 = bsb.radius + surf_dist / 2.0;
+ float t = d1 / (d1 + d2);
+
+ if(t < 0.0) t = 0.0;
+ if(t > 1.0) t = 1.0;
+
+ sph->center = bsa.center * t + bsb.center * (1.0 - t);
+ sph->radius = std::max(dist * t + bsb.radius, dist * (1.0f - t) + bsa.radius);
+ return true;
+}
+
+bool calc_bounding_sphere(Sphere *sph, const GeomObject **objv, int num)
+{
+ if(num <= 0) return false;
+
+ if(!calc_bounding_sphere(sph, objv[0])) {
+ return false;
+ }
+
+ for(int i=1; i<num; i++) {
+ if(!calc_bounding_sphere(sph, sph, objv[i])) {
+ return false;
+ }
+ }
+ return true;
+}
+
+bool calc_bounding_sphere(Sphere *sph, const Vec3 *v, int num, const Mat4 &xform)
+{
+ if(num <= 0) return false;
+
+ sph->center = Vec3(0.0, 0.0, 0.0);
+ for(int i=0; i<num; i++) {
+ sph->center += xform * v[i];
+ }
+ sph->center /= (float)num;
+
+ float rad_sq = 0.0f;
+ for(int i=0; i<num; i++) {
+ Vec3 dir = xform * v[i] - sph->center;
+ rad_sq = std::max(rad_sq, dot(dir, dir));
+ }
+ sph->radius = sqrt(rad_sq);
+ return true;
+}
+
+bool calc_bounding_aabox(AABox *box, const GeomObject *obj)
+{
+ switch(obj->type) {
+ case GOBJ_AABOX:
+ *box = *(AABox*)obj;
+ break;
+
+ case GOBJ_BOX:
+ {
+ Vec3 v[8];
+ for(int i=0; i<8; i++) {
+ v[i] = BOX(obj)->get_corner(i);
+ }
+ calc_bounding_aabox(box, v, 8);
+ }
+ break;
+
+ case GOBJ_SPHERE:
+ {
+ float r = SPHERE(obj)->radius;
+ box->min = SPHERE(obj)->center - Vec3(r, r, r);
+ box->max = SPHERE(obj)->center + Vec3(r, r, r);
+ }
+ break;
+
+ case GOBJ_PLANE:
+ default:
+ return false;
+ }
+ return true;
+}
+
+bool calc_bounding_aabox(AABox *box, const GeomObject *a, const GeomObject *b)
+{
+ AABox bba, bbb;
+
+ if(!calc_bounding_aabox(&bba, a) || !calc_bounding_aabox(&bbb, b)) {
+ return false;
+ }
+
+ for(int i=0; i<3; i++) {
+ box->min[i] = std::min(bba.min[i], bbb.min[i]);
+ box->max[i] = std::max(bba.max[i], bbb.max[i]);
+ }
+ return true;
+}
+
+bool calc_bounding_aabox(AABox *box, const GeomObject **objv, int num)
+{
+ if(num <= 0) return false;
+
+ if(!calc_bounding_aabox(box, objv[0])) {
+ return false;
+ }
+
+ for(int i=1; i<num; i++) {
+ if(!calc_bounding_aabox(box, box, objv[i])) {
+ return false;
+ }
+ }
+ return true;
+}
+
+bool calc_bounding_aabox(AABox *box, const Vec3 *v, int num, const Mat4 &xform)
+{
+ if(num <= 0) return false;
+
+ box->min = box->max = xform * v[0];
+ for(int i=1; i<num; i++) {
+ Vec3 p = xform * v[i];
+
+ for(int j=0; j<3; j++) {
+ box->min[j] = std::min(box->min[j], p[j]);
+ box->max[j] = std::max(box->max[j], p[j]);
+ }
+ }
+ return true;
+}
+
+bool intersect_sphere_sphere(Disc *result, const Sphere &a, const Sphere &b)
+{
+ Vec3 dir = b.center - a.center;
+
+ float dist_sq = length_sq(dir);
+ if(dist_sq <= 1e-8) return false;
+
+ float rsum = a.radius + b.radius;
+ float rdif = fabs(a.radius - b.radius);
+ if(dist_sq > rsum * rsum || dist_sq < rdif * rdif) {
+ return false;
+ }
+
+ float dist = sqrt(dist_sq);
+ float t = (dist_sq + a.radius * a.radius - b.radius * b.radius) / (2.0 * sqrt(dist_sq));
+
+ result->pt = a.center + dir * t;
+ result->normal = dir / dist;
+ result->radius = sin(acos(t)) * a.radius;
+ return true;
+}
+
+bool intersect_plane_plane(Ray *result, const Plane &a, const Plane &b)
+{
+ return false; // TODO
+}
+
+bool intersect_sphere_plane(Sphere *result, const Sphere &s, const Plane &p)
+{
+ return false; // TODO
+}
+
+bool intersect_plane_sphere(Sphere *result, const Plane &p, const Sphere &s)
+{
+ return false; // TODO
+}
+
+bool intersect_aabox_aabox(AABox *res, const AABox &a, const AABox &b)
+{
+ for(int i=0; i<3; i++) {
+ res->min[i] = std::max(a.min[i], b.min[i]);
+ res->max[i] = std::min(a.max[i], b.max[i]);
+
+ if(res->max[i] < res->min[i]) {
+ res->max[i] = res->min[i];
+ }
+ }
+ return res->min.x != res->max.x && res->min.y != res->max.y && res->min.z != res->max.z;
+}
#ifndef GEOMOBJ_H_
#define GEOMOBJ_H_
+/* TODO:
+ * - implement distance functions
+ */
+
#include <gmath/gmath.h>
enum GeomObjectType {
GOBJ_UNKNOWN,
GOBJ_SPHERE,
GOBJ_AABOX,
+ GOBJ_BOX,
GOBJ_PLANE
};
class GeomObject {
public:
- virtual ~GeomObject();
- virtual GeomObjectType get_type() const = 0;
+ GeomObjectType type;
- virtual void set_union(const GeomObject *obj1, const GeomObject *obj2) = 0;
- virtual void set_intersection(const GeomObject *obj1, const GeomObject *obj2) = 0;
+ GeomObject();
+ virtual ~GeomObject();
virtual bool intersect(const Ray &ray, HitPoint *hit = 0) const = 0;
virtual bool contains(const Vec3 &pt) const = 0;
virtual float distance(const Vec3 &v) const = 0;
+ virtual float signed_distance(const Vec3 &v) const = 0;
};
class Sphere : public GeomObject {
Sphere();
Sphere(const Vec3 ¢er, float radius);
- GeomObjectType get_type() const;
-
- void set_union(const GeomObject *obj1, const GeomObject *obj2);
- void set_intersection(const GeomObject *obj1, const GeomObject *obj2);
-
- bool intersect(const Ray &ray, HitPoint *hit = 0) const;
- bool contains(const Vec3 &pt) const;
+ virtual bool intersect(const Ray &ray, HitPoint *hit = 0) const;
+ virtual bool contains(const Vec3 &pt) const;
- float distance(const Vec3 &v) const;
+ virtual float distance(const Vec3 &v) const;
+ virtual float signed_distance(const Vec3 &v) const;
};
class AABox : public GeomObject {
AABox();
AABox(const Vec3 &min, const Vec3 &max);
- GeomObjectType get_type() const;
+ virtual Vec3 get_corner(int idx) const;
+
+ virtual bool intersect(const Ray &ray, HitPoint *hit = 0) const;
+ virtual bool contains(const Vec3 &pt) const;
+
+ virtual float distance(const Vec3 &v) const;
+ virtual float signed_distance(const Vec3 &v) const;
+};
+
+class Box : public AABox {
+public:
+ Mat4 xform;
+
+ Box();
+ Box(const Vec3 &min, const Vec3 &max);
+ Box(const Vec3 &pos, const Vec3 &vi, const Vec3 &vj, const Vec3 &vk);
+ Box(const Vec3 *varr, int vcount);
- void set_union(const GeomObject *obj1, const GeomObject *obj2);
- void set_intersection(const GeomObject *obj1, const GeomObject *obj2);
+ virtual Vec3 get_corner(int idx) const;
- bool intersect(const Ray &ray, HitPoint *hit = 0) const;
- bool contains(const Vec3 &pt) const;
+ virtual bool intersect(const Ray &ray, HitPoint *hit = 0) const;
+ virtual bool contains(const Vec3 &pt) const;
- float distance(const Vec3 &v) const;
+ virtual float distance(const Vec3 &v) const;
+ virtual float signed_distance(const Vec3 &v) const;
};
+
class Plane : public GeomObject {
public:
Vec3 pt, normal;
Plane(const Vec3 &p1, const Vec3 &p2, const Vec3 &p3);
Plane(const Vec3 &normal, float dist);
- GeomObjectType get_type() const;
+ virtual bool intersect(const Ray &ray, HitPoint *hit = 0) const;
+ virtual bool contains(const Vec3 &pt) const;
- void set_union(const GeomObject *obj1, const GeomObject *obj2);
- void set_intersection(const GeomObject *obj1, const GeomObject *obj2);
+ virtual float distance(const Vec3 &v) const;
+ virtual float signed_distance(const Vec3 &v) const;
+};
- bool intersect(const Ray &ray, HitPoint *hit = 0) const;
- bool contains(const Vec3 &pt) const;
+class Disc : public Plane {
+public:
+ float radius;
+
+ Disc();
+ Disc(const Vec3 &pt, const Vec3 &normal, float rad);
+ Disc(const Vec3 &normal, float dist, float rad);
- float distance(const Vec3 &v) const;
+ virtual bool intersect(const Ray &ray, HitPoint *hit = 0) const;
+ //! true if the projection of pt to the plane is contained within the disc radius
+ virtual bool contains(const Vec3 &pt) const;
+
+ virtual float distance(const Vec3 &v) const;
+ virtual float signed_distance(const Vec3 &v) const;
};
+//! project point to plane
+Vec3 proj_point_plane(const Vec3 &pt, const Plane &plane);
+
+//! calculate the bounding sphere of any object
+bool calc_bounding_sphere(Sphere *sph, const GeomObject *obj);
+//! calculate the bounding sphere of two objects
+bool calc_bounding_sphere(Sphere *sph, const GeomObject *a, const GeomObject *b);
+//! calculate the bounding sphere of multiple objects
+bool calc_bounding_sphere(Sphere *sph, const GeomObject **objv, int num);
+//! calculate the bounding sphere of multiple points, optionally transformed by `xform`
+bool calc_bounding_sphere(Sphere *sph, const Vec3 *v, int num, const Mat4 &xform = Mat4::identity);
+
+//! calculate the bounding axis-aligned box of any object
+bool calc_bounding_aabox(AABox *box, const GeomObject *obj);
+//! calculate the bounding axis-aligned box of two objects
+bool calc_bounding_aabox(AABox *box, const GeomObject *a, const GeomObject *b);
+//! calculate the bounding axis-aligned box of multiple objects
+bool calc_bounding_aabox(AABox *box, const GeomObject **objv, int num);
+//! calculate the bounding axis-aligned box of multiple points, optionally transformed by `xform`
+bool calc_bounding_aabox(AABox *box, const Vec3 *v, int num, const Mat4 &xform = Mat4::identity);
+
+//! calculate the intersection plane of two spheres. false if there is no plane or infinite planes.
+bool intersect_sphere_sphere(Plane *result, const Sphere &a, const Sphere &b);
+//! calculate the intersection line of two planes. returns false if planes are exactly parallel.
+bool intersect_plane_plane(Ray *result, const Plane &a, const Plane &b);
+/*! calculate the intesection circle of a plane and a sphere. returns false if they don't intersect.
+ * \{
+ */
+bool intersect_sphere_plane(Sphere *result, const Sphere &s, const Plane &p);
+bool intersect_plane_sphere(Sphere *result, const Plane &p, const Sphere &s);
+//! \}
+
+//! calculate the intersection of two axis-aligned bounding boxes
+bool intersect_aabox_aabox(AABox *res, const AABox &a, const AABox &b);
+
#endif // GEOMOBJ_H_