--- /dev/null
+#include <stdlib.h>
+#include <float.h>
+#include <algorithm>
+#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()
+{
+}
+
+bool GeomObject::valid() const
+{
+ return true;
+}
+
+void GeomObject::invalidate()
+{
+}
+
+float GeomObject::distance(const Vec3 &v) const
+{
+ return sqrt(distance_sq(v));
+}
+
+float GeomObject::signed_distance(const Vec3 &v) const
+{
+ return sqrt(signed_distance_sq(v));
+}
+
+Sphere::Sphere()
+{
+ type = GOBJ_SPHERE;
+ radius = 1.0;
+}
+
+Sphere::Sphere(const Vec3 ¢, float radius)
+ : center(cent)
+{
+ type = GOBJ_SPHERE;
+ this->radius = radius;
+}
+
+bool Sphere::valid() const
+{
+ return radius >= 0.0f;
+}
+
+void Sphere::invalidate()
+{
+ center = Vec3(0, 0, 0);
+ radius = -1;
+}
+
+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;
+}
+
+bool Sphere::contains(const Vec3 &pt) const
+{
+ return length_sq(pt - center) <= radius * radius;
+}
+
+float Sphere::distance_sq(const Vec3 &v) const
+{
+ return std::max(length_sq(v - center) - radius * radius, 0.0f);
+}
+
+float Sphere::signed_distance_sq(const Vec3 &v) const
+{
+ return length_sq(v - center) - radius * radius;
+}
+
+AABox::AABox()
+{
+ type = GOBJ_AABOX;
+}
+
+AABox::AABox(const Vec3 &vmin, const Vec3 &vmax)
+ : min(vmin), max(vmax)
+{
+ type = GOBJ_AABOX;
+}
+
+bool AABox::valid() const
+{
+ return min.x <= max.x && min.y <= max.y && min.z <= max.z;
+}
+
+void AABox::invalidate()
+{
+ min = Vec3(FLT_MAX, FLT_MAX, FLT_MAX);
+ max = Vec3(-FLT_MAX, -FLT_MAX, -FLT_MAX);
+}
+
+Vec3 AABox::get_corner(int idx) const
+{
+ Vec3 v[] = {min, max};
+ static const int xidx[] = {0, 1, 1, 0, 0, 1, 1, 0};
+ static const int yidx[] = {0, 0, 0, 0, 1, 1, 1, 1};
+ static const int zidx[] = {0, 0, 1, 1, 0, 0, 1, 1};
+ return Vec3(v[xidx[idx]].x, v[yidx[idx]].y, v[zidx[idx]].z);
+}
+
+Plane AABox::get_plane(int pidx) const
+{
+ Vec3 c = (max - min) * 0.5f;
+ switch(pidx) {
+ case AABOX_PLANE_PX:
+ return Plane(Vec3(max.x, c.y, c.z), Vec3(1, 0, 0));
+ case AABOX_PLANE_NX:
+ return Plane(Vec3(min.x, c.y, c.z), Vec3(-1, 0, 0));
+ case AABOX_PLANE_PY:
+ return Plane(Vec3(c.x, max.x, c.z), Vec3(0, 1, 0));
+ case AABOX_PLANE_NY:
+ return Plane(Vec3(c.x, min.x, c.z), Vec3(0, -1, 0));
+ case AABOX_PLANE_PZ:
+ return Plane(Vec3(c.x, c.y, max.z), Vec3(0, 0, 1));
+ case AABOX_PLANE_NZ:
+ return Plane(Vec3(c.x, c.y, min.z), Vec3(0, 0, -1));
+ default:
+ break;
+ }
+ abort();
+ return Plane();
+}
+
+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;
+}
+
+bool AABox::contains(const Vec3 &v) const
+{
+ return v.x >= min.x && v.y >= min.y && v.z >= min.z &&
+ v.x <= max.x && v.y <= max.y && v.z <= max.z;
+}
+
+#define SQ(x) ((x) * (x))
+float AABox::distance_sq(const Vec3 &v) const
+{
+ float dsq = 0.0f;
+
+ for(int i=0; i<3; i++) {
+ if(v[i] < min[i]) dsq += SQ(min[i] - v[i]);
+ if(v[i] > max[i]) dsq += SQ(v[i] - max[i]);
+ }
+ return dsq;
+}
+
+float AABox::signed_distance_sq(const Vec3 &v) const
+{
+ if(!contains(v)) {
+ return distance_sq(v);
+ }
+
+ float dsq = 0.0f;
+ for(int i=0; i<3; i++) {
+ float dmin = v[i] - min[i];
+ float dmax = max[i] - v[i];
+ dsq -= dmin < dmax ? SQ(dmin) : SQ(dmax);
+ }
+ return dsq;
+}
+
+Box::Box()
+{
+ type = GOBJ_BOX;
+}
+
+Box::Box(const AABox &aabox, const Mat4 &xform)
+ : xform(xform)
+{
+ type = GOBJ_BOX;
+ min = aabox.min;
+ max = aabox.max;
+}
+
+void Box::invalidate()
+{
+ AABox::invalidate();
+ xform = Mat4::identity;
+}
+
+Box::Box(const Vec3 &min, const Vec3 &max)
+ : AABox(min, max)
+{
+ type = GOBJ_BOX;
+}
+
+Box::Box(const Vec3 &min, const Vec3 &max, const Mat4 &xform)
+ : AABox(min, max), xform(xform)
+{
+ type = GOBJ_BOX;
+}
+
+// XXX all this shit is completely untested
+Box::Box(const Vec3 &pos, const Vec3 &vi, const Vec3 &vj, const Vec3 &vk)
+{
+ type = GOBJ_BOX;
+ 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)
+{
+ type = GOBJ_BOX;
+ calc_bounding_aabox(this, varr, vcount);
+}
+
+Vec3 Box::get_corner(int idx) const
+{
+ return xform * AABox::get_corner(idx);
+}
+
+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_sq(const Vec3 &v) const
+{
+ return 0.0f; // TODO
+}
+
+float Box::signed_distance_sq(const Vec3 &v) const
+{
+ return 0.0f; // TODO
+}
+
+Plane::Plane()
+ : normal(0.0, 1.0, 0.0)
+{
+ type = GOBJ_PLANE;
+}
+
+Plane::Plane(const Vec3 &p, const Vec3 &norm)
+ : pt(p)
+{
+ type = GOBJ_PLANE;
+ normal = normalize(norm);
+}
+
+Plane::Plane(const Vec3 &p1, const Vec3 &p2, const Vec3 &p3)
+ : pt(p1)
+{
+ type = GOBJ_PLANE;
+ normal = normalize(cross(p2 - p1, p3 - p1));
+}
+
+Plane::Plane(const Vec3 &normal, float dist)
+{
+ type = GOBJ_PLANE;
+ this->normal = normalize(normal);
+ pt = this->normal * dist;
+}
+
+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->dist = t;
+ hit->pos = ray.origin + ray.dir * t;
+ hit->normal = normal;
+ hit->obj = this;
+ }
+ return true;
+}
+
+bool Plane::contains(const Vec3 &v) const
+{
+ return dot(v, normal) <= 0.0;
+}
+
+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);
+}
+
+float Plane::distance_sq(const Vec3 &v) const
+{
+ float d = distance(v);
+ return d * d;
+}
+
+float Plane::signed_distance_sq(const Vec3 &v) const
+{
+ float d = distance(v);
+ return dot(v, normal) >= 0.0f ? d * d : -(d * d);
+}
+
+
+Disc::Disc()
+{
+ type = GOBJ_DISC;
+ radius = 1.0;
+}
+
+Disc::Disc(const Vec3 &pt, const Vec3 &normal, float rad)
+ : Plane(pt, normal)
+{
+ type = GOBJ_DISC;
+ radius = rad;
+}
+
+Disc::Disc(const Vec3 &normal, float dist, float rad)
+ : Plane(normal, dist)
+{
+ type = GOBJ_DISC;
+ radius = rad;
+}
+
+bool Disc::valid() const
+{
+ return radius >= 0.0f;
+}
+
+void Disc::invalidate()
+{
+ radius = -1;
+}
+
+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_sq(const Vec3 &v) const
+{
+ return 0.0; // TODO
+}
+
+float Disc::signed_distance_sq(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)
+{
+ if(!obj->valid()) {
+ sph->invalidate();
+ return true;
+ }
+
+ 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)
+{
+ if(!obj->valid()) {
+ box->invalidate();
+ return true;
+ }
+
+ 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 calc_bounding_box(Box *box, const GeomObject *obj)
+{
+ if(!obj->valid()) {
+ box->invalidate();
+ return true;
+ }
+
+ switch(obj->type) {
+ case GOBJ_BOX:
+ *box = *(Box*)obj;
+ break;
+
+ case GOBJ_AABOX:
+ box->min = BOX(obj)->min;
+ box->max = BOX(obj)->max;
+ box->xform = Mat4::identity;
+ 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);
+ box->xform = Mat4::identity;
+ }
+ break;
+
+ case GOBJ_PLANE:
+ default:
+ return false;
+ }
+ 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;
+}
+
+bool collision_sphere_aabox(const Sphere &s, const AABox &b)
+{
+ return b.distance_sq(s.center) <= s.radius * s.radius;
+}
projects / ld42_outofspace / blobdiff