+/*
+RetroRay - integrated standalone vintage modeller/renderer
+Copyright (C) 2023 John Tsiombikas <nuclear@mutantstargoat.com>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program. If not, see <https://www.gnu.org/licenses/>.
+*/
+#include "rt.h"
+
+
+int ray_object(const cgm_ray *ray, const struct object *obj, struct csghit *hit)
+{
+ int i, res;
+ cgm_ray localray = *ray;
+
+ cgm_rmul_mr(&localray, obj->inv_xform);
+
+ switch(obj->type) {
+ case OBJ_SPHERE:
+ res = ray_sphere(ray, (const struct sphere*)obj, hit);
+ break;
+
+ default:
+ res = 0;
+ }
+
+ if(res && hit) {
+ for(i=0; i<hit->ivcount; i++) {
+ cgm_vmul_m4v3(&hit->ivlist[i].a.pos, obj->xform);
+ cgm_vmul_m3v3(&hit->ivlist[i].a.norm, obj->xform);
+ cgm_vmul_m4v3(&hit->ivlist[i].b.pos, obj->xform);
+ cgm_vmul_m3v3(&hit->ivlist[i].b.norm, obj->xform);
+ }
+ }
+ return res;
+}
+
+int ray_sphere(const cgm_ray *ray, const struct sphere *sph, struct csghit *hit)
+{
+ int i;
+ float a, b, c, d, sqrt_d, t1, t2, invrad;
+ struct rayhit *rhptr;
+
+ a = cgm_vdot(&ray->dir, &ray->dir);
+ b = 2.0f * ray->dir.x * (ray->origin.x - sph->pos.x) +
+ 2.0f * ray->dir.y * (ray->origin.y - sph->pos.y) +
+ 2.0f * ray->dir.z * (ray->origin.z - sph->pos.z);
+ c = cgm_vdot(&sph->pos, &sph->pos) + cgm_vdot(&ray->origin, &ray->origin) +
+ cgm_vdot(&sph->pos, &ray->origin) * -2.0f - sph->rad * sph->rad;
+
+ if((d = b * b - 4.0 * a * c) < 0.0) return 0;
+
+ sqrt_d = sqrt(d);
+ t1 = (-b + sqrt_d) / (2.0 * a);
+ t2 = (-b - sqrt_d) / (2.0 * a);
+
+ if((t1 < 1e-6f && t2 < 1e-6f) || (t1 > 1.0f && t2 > 1.0f)) {
+ return 0;
+ }
+
+ if(hit) {
+ if(t1 < 1e-6f || t1 > 1.0f) {
+ t1 = t2;
+ } else if(t2 < 1e-6f || t2 > 1.0f) {
+ t2 = t1;
+ }
+ if(t2 < t1) {
+ float tmp = t1;
+ t1 = t2;
+ t2 = tmp;
+ }
+
+ hit->ivcount = 1;
+ hit->ivlist[0].a.t = t1;
+ hit->ivlist[0].b.t = t2;
+ invrad = 1.0f / sph->rad;
+
+ rhptr = &hit->ivlist[0].a;
+ for(i=0; i<2; i++) {
+ cgm_raypos(&rhptr->pos, ray, rhptr->t);
+ rhptr->norm.x = rhptr->pos.x * invrad;
+ rhptr->norm.y = rhptr->pos.y * invrad;
+ rhptr->norm.z = rhptr->pos.z * invrad;
+ rhptr->uv.x = (atan2(rhptr->norm.z, rhptr->norm.x) + CGM_PI) / (2.0 * CGM_PI);
+ rhptr->uv.y = acos(rhptr->norm.y) / CGM_PI;
+ rhptr->obj = (struct object*)sph;
+ rhptr = &hit->ivlist[0].b;
+ }
+ }
+ return 1;
+}
+
+int ray_csg(const cgm_ray *ray, const struct csgnode *csg, struct csghit *hit)
+{
+ return 0;
+}
projects / retroray / commitdiff