2 RetroRay - integrated standalone vintage modeller/renderer
3 Copyright (C) 2023 John Tsiombikas <nuclear@mutantstargoat.com>
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation, either version 3 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <https://www.gnu.org/licenses/>.
21 int ray_object(const cgm_ray *ray, const struct object *obj, struct csghit *hit)
24 cgm_ray localray = *ray;
26 cgm_rmul_mr(&localray, obj->inv_xform);
30 res = ray_sphere(ray, (const struct sphere*)obj, hit);
38 for(i=0; i<hit->ivcount; i++) {
39 cgm_vmul_m4v3(&hit->ivlist[i].a.pos, obj->xform);
40 cgm_vmul_m3v3(&hit->ivlist[i].a.norm, obj->xform);
41 cgm_vmul_m4v3(&hit->ivlist[i].b.pos, obj->xform);
42 cgm_vmul_m3v3(&hit->ivlist[i].b.norm, obj->xform);
48 int ray_sphere(const cgm_ray *ray, const struct sphere *sph, struct csghit *hit)
51 float a, b, c, d, sqrt_d, t1, t2, invrad;
54 a = cgm_vdot(&ray->dir, &ray->dir);
55 b = 2.0f * ray->dir.x * (ray->origin.x - sph->pos.x) +
56 2.0f * ray->dir.y * (ray->origin.y - sph->pos.y) +
57 2.0f * ray->dir.z * (ray->origin.z - sph->pos.z);
58 c = cgm_vdot(&sph->pos, &sph->pos) + cgm_vdot(&ray->origin, &ray->origin) +
59 cgm_vdot(&sph->pos, &ray->origin) * -2.0f - sph->rad * sph->rad;
61 if((d = b * b - 4.0 * a * c) < 0.0) return 0;
64 t1 = (-b + sqrt_d) / (2.0 * a);
65 t2 = (-b - sqrt_d) / (2.0 * a);
67 if((t1 < 1e-6f && t2 < 1e-6f) || (t1 > 1.0f && t2 > 1.0f)) {
72 if(t1 < 1e-6f || t1 > 1.0f) {
74 } else if(t2 < 1e-6f || t2 > 1.0f) {
84 hit->ivlist[0].a.t = t1;
85 hit->ivlist[0].b.t = t2;
86 invrad = 1.0f / sph->rad;
88 rhptr = &hit->ivlist[0].a;
90 cgm_raypos(&rhptr->pos, ray, rhptr->t);
91 rhptr->norm.x = rhptr->pos.x * invrad;
92 rhptr->norm.y = rhptr->pos.y * invrad;
93 rhptr->norm.z = rhptr->pos.z * invrad;
94 rhptr->uv.x = (atan2(rhptr->norm.z, rhptr->norm.x) + CGM_PI) / (2.0 * CGM_PI);
95 rhptr->uv.y = acos(rhptr->norm.y) / CGM_PI;
96 rhptr->obj = (struct object*)sph;
97 rhptr = &hit->ivlist[0].b;
103 int ray_csg(const cgm_ray *ray, const struct csgnode *csg, struct csghit *hit)