--- /dev/null
+#include <assert.h>
+#include <float.h>
+#include <algorithm>
+#include "geom.h"
+
+GeomObject::~GeomObject()
+{
+}
+
+
+Sphere::Sphere()
+{
+ radius = 1.0;
+}
+
+Sphere::Sphere(const Vec3 ¢, float radius)
+ : center(cent)
+{
+ this->radius = radius;
+}
+
+void Sphere::set_union(const GeomObject *obj1, const GeomObject *obj2)
+{
+ const Sphere *sph1 = dynamic_cast<const Sphere*>(obj1);
+ const Sphere *sph2 = dynamic_cast<const Sphere*>(obj2);
+
+ if(!sph1 || !sph2) {
+ fprintf(stderr, "Sphere::set_union: arguments must be spheres");
+ return;
+ }
+
+ 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 b = 2.0 * ray.dir.x * (ray.origin.x - center.x) +
+ 2.0 * ray.dir.y * (ray.origin.y - center.y) +
+ 2.0 * ray.dir.z * (ray.origin.z - center.z);
+ float c = dot(ray.origin, ray.origin) + dot(center, center) -
+ 2.0 * dot(ray.origin, center) - radius * radius;
+
+ float discr = b * b - 4.0 * a * c;
+ if(discr < 1e-4) {
+ return false;
+ }
+
+ float sqrt_discr = sqrt(discr);
+ float t0 = (-b + sqrt_discr) / (2.0 * a);
+ float t1 = (-b - sqrt_discr) / (2.0 * a);
+
+ if(t0 < 1e-4)
+ t0 = t1;
+ if(t1 < 1e-4)
+ t1 = t0;
+
+ float t = t0 < t1 ? t0 : t1;
+ if(t < 1e-4) {
+ return false;
+ }
+
+ // fill the HitPoint structure
+ if(hit) {
+ hit->obj = this;
+ hit->dist = t;
+ hit->pos = ray.origin + ray.dir * t;
+ hit->normal = (hit->pos - center) / radius;
+ }
+ return true;
+}
+
+
+AABox::AABox()
+{
+}
+
+AABox::AABox(const Vec3 &vmin, const Vec3 &vmax)
+ : min(vmin), max(vmax)
+{
+}
+
+void AABox::set_union(const GeomObject *obj1, const GeomObject *obj2)
+{
+ const AABox *box1 = dynamic_cast<const AABox*>(obj1);
+ const AABox *box2 = dynamic_cast<const AABox*>(obj2);
+
+ if(!box1 || !box2) {
+ fprintf(stderr, "AABox::set_union: arguments must be AABoxes too\n");
+ return;
+ }
+
+ 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)
+{
+ const AABox *box1 = dynamic_cast<const AABox*>(obj1);
+ const AABox *box2 = dynamic_cast<const AABox*>(obj2);
+
+ if(!box1 || !box2) {
+ fprintf(stderr, "AABox::set_intersection: arguments must be AABoxes too\n");
+ return;
+ }
+
+ 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];
+ }
+ }
+}
+
+bool AABox::intersect(const Ray &ray, HitPoint *hit) const
+{
+ Vec3 param[2] = {min, max};
+ Vec3 inv_dir(1.0 / ray.dir.x, 1.0 / ray.dir.y, 1.0 / ray.dir.z);
+ int sign[3] = {inv_dir.x < 0, inv_dir.y < 0, inv_dir.z < 0};
+
+ float tmin = (param[sign[0]].x - ray.origin.x) * inv_dir.x;
+ float tmax = (param[1 - sign[0]].x - ray.origin.x) * inv_dir.x;
+ float tymin = (param[sign[1]].y - ray.origin.y) * inv_dir.y;
+ float tymax = (param[1 - sign[1]].y - ray.origin.y) * inv_dir.y;
+
+ if(tmin > tymax || tymin > tmax) {
+ return false;
+ }
+ if(tymin > tmin) {
+ tmin = tymin;
+ }
+ if(tymax < tmax) {
+ tmax = tymax;
+ }
+
+ float tzmin = (param[sign[2]].z - ray.origin.z) * inv_dir.z;
+ float tzmax = (param[1 - sign[2]].z - ray.origin.z) * inv_dir.z;
+
+ if(tmin > tzmax || tzmin > tmax) {
+ return false;
+ }
+ if(tzmin > tmin) {
+ tmin = tzmin;
+ }
+ if(tzmax < tmax) {
+ tmax = tzmax;
+ }
+
+ float t = tmin < 1e-4 ? tmax : tmin;
+ if(t >= 1e-4) {
+
+ if(hit) {
+ hit->obj = this;
+ hit->dist = t;
+ hit->pos = ray.origin + ray.dir * t;
+
+ float min_dist = FLT_MAX;
+ Vec3 offs = min + (max - min) / 2.0;
+ Vec3 local_hit = hit->pos - offs;
+
+ static const Vec3 axis[] = {
+ Vec3(1, 0, 0), Vec3(0, 1, 0), Vec3(0, 0, 1)
+ };
+ //int tcidx[][2] = {{2, 1}, {0, 2}, {0, 1}};
+
+ for(int i=0; i<3; i++) {
+ float dist = fabs((max[i] - offs[i]) - fabs(local_hit[i]));
+ if(dist < min_dist) {
+ min_dist = dist;
+ hit->normal = axis[i] * (local_hit[i] < 0.0 ? 1.0 : -1.0);
+ //hit->texcoord = Vec2(hit->pos[tcidx[i][0]], hit->pos[tcidx[i][1]]);
+ }
+ }
+ }
+ return true;
+ }
+ return false;
+
+}
+
+Plane::Plane()
+ : normal(0.0, 1.0, 0.0)
+{
+}
+
+Plane::Plane(const Vec3 &p, const Vec3 &norm)
+ : pt(p)
+{
+ normal = normalize(norm);
+}
+
+Plane::Plane(const Vec3 &p1, const Vec3 &p2, const Vec3 &p3)
+ : pt(p1)
+{
+ normal = normalize(cross(p2 - p1, p3 - p1));
+}
+
+Plane::Plane(const Vec3 &normal, float dist)
+{
+ this->normal = normalize(normal);
+ pt = this->normal * dist;
+}
+
+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);
+ if(fabs(ndotdir) < 1e-4) {
+ return false;
+ }
+
+ if(hit) {
+ Vec3 ptdir = pt - ray.origin;
+ float t = dot(normal, ptdir) / ndotdir;
+
+ hit->pos = ray.origin + ray.dir * t;
+ hit->normal = normal;
+ hit->obj = this;
+ }
+ return true;
+}
+
+float sphere_distance(const Vec3 ¢, float rad, const Vec3 &pt)
+{
+ return length(pt - cent) - rad;
+}
+
+// TODO version which takes both radii into account
+float capsule_distance(const Vec3 &a, float ra, const Vec3 &b, float rb, const Vec3 &pt)
+{
+ Vec3 ab_dir = b - a;
+ float ab_len_sq = length_sq(ab_dir);
+
+ if(fabs(ab_len_sq) < 1e-5) {
+ // if a == b, the capsule is a sphere with radius the maximum of the capsule radii
+ return sphere_distance(a, std::max(ra, rb), pt);
+ }
+ float ab_len = sqrt(ab_len_sq);
+
+ Vec3 ap_dir = pt - a;
+
+ float t = dot(ap_dir, ab_dir / ab_len) / ab_len;
+ if(t < 0.0) {
+ return sphere_distance(a, ra, pt);
+ }
+ if(t >= 1.0) {
+ return sphere_distance(b, rb, pt);
+ }
+
+ Vec3 pproj = a + ab_dir * t;
+ return length(pproj - pt) - ra;
+}
+
+#if 0
+float capsule_distance(const Vec3 &a, float ra, const Vec3 &b, float rb, const Vec3 &pt)
+{
+ Vec3 ab_dir = b - a;
+
+ if(fabs(length_sq(ab_dir)) < 1e-5) {
+ // if a == b, the capsule is a sphere with radius the maximum of the capsule radii
+ return sphere_distance(a, std::max(ra, rb), pt);
+ }
+ float ab_len = length(ab_dir);
+
+ Vec3 ap_dir = pt - a;
+ Vec3 rotaxis = normalize(cross(ab_dir, ap_dir));
+
+ Mat4 rmat;
+ rmat.set_rotation(rotaxis, M_PI / 2.0);
+ Vec3 right = rmat * ab_dir / ab_len;
+
+ // XXX I think this check is redundant, always false, due to the cross product order
+ //assert(dot(right, ab_dir) >= 0.0);
+ if(dot(right, ab_dir) < 0.0) {
+ right = -right;
+ }
+ Vec3 aa = a + right * ra;
+ Vec3 bb = b + right * rb;
+
+ // project pt to the line segment bb-aa, see if the projection lies within the interval [0, 1)
+ Vec3 aabb_dir = bb - aa;
+ float aabb_len = length(aabb_dir);
+ Vec3 aap_dir = pt - aa;
+
+ float t = dot(aap_dir, aabb_dir / aabb_len) / aabb_len;
+ if(t < 0.0) {
+ return sphere_distance(a, ra, pt);
+ }
+ if(t >= 1.0) {
+ return sphere_distance(b, rb, pt);
+ }
+
+ Vec3 ppt = aa + aabb_dir * t;
+ Vec3 norm = ppt - pt;
+ float dist = length(norm);
+
+ if(dot(norm, right) < 0.0) {
+ // inside the cone
+ dist = -dist;
+ }
+ return dist;
+}
+#endif
projects / vrfileman / blobdiff