+ int i, j;
+ float aspect = (float)width / (float)height;
+
+ for(i=0; i<height; i++) {
+ for(j=0; j<width; j++) {
+ csg_render_pixel(j, i, width, height, aspect, pixels);
+ pixels += 3;
+ }
+ }
+}
+
+static void calc_primary_ray(struct ray *ray, int x, int y, int w, int h, float aspect)
+{
+ ray->dx = aspect * ((float)x / (float)w * 2.0f - 1.0f);
+ ray->dy = 1.0f - (float)y / (float)h * 2.0f;
+ ray->dz = -1.0f / tan(cam.fov * 0.5f);
+
+ ray->x = 0;
+ ray->y = 0;
+ ray->z = 0;
+
+ xform_ray(ray, cam.xform);
+}
+
+static int ray_trace(struct ray *ray, float *col)
+{
+ struct hit hit;
+
+ if(!find_intersection(ray, &hit)) {
+ background(col, ray);
+ return 0;
+ }
+
+ shade(col, ray, &hit);
+ return 1;
+}
+
+#define NULLXPOS(o) ((o)->ob.xform[12])
+#define NULLYPOS(o) ((o)->ob.xform[13])
+#define NULLZPOS(o) ((o)->ob.xform[14])
+
+static void shade(float *col, struct ray *ray, struct hit *hit)
+{
+ float ndotl, ndoth, len, falloff, spec;
+ csg_object *o, *lt = plights;
+ float dcol[3], scol[3] = {0};
+ float ldir[3], lcol[3], hdir[3];
+ struct ray sray;
+ struct hit tmphit;
+
+ o = hit->o;
+ dcol[0] = ambient[0];
+ dcol[1] = ambient[1];
+ dcol[2] = ambient[2];
+
+ while(lt) {
+ ldir[0] = NULLXPOS(lt) - hit->x;
+ ldir[1] = NULLYPOS(lt) - hit->y;
+ ldir[2] = NULLZPOS(lt) - hit->z;
+
+ sray.x = hit->x;
+ sray.y = hit->y;
+ sray.z = hit->z;
+ sray.dx = ldir[0];
+ sray.dy = ldir[1];
+ sray.dz = ldir[2];
+
+ if(!find_intersection(&sray, &tmphit) || tmphit.t < 0.000001 || tmphit.t > 1.0f) {
+ if((len = sqrt(ldir[0] * ldir[0] + ldir[1] * ldir[1] + ldir[2] * ldir[2])) != 0.0f) {
+ float s = 1.0f / len;
+ ldir[0] *= s;
+ ldir[1] *= s;
+ ldir[2] *= s;
+ }
+ falloff = 1.0f / (len * len);
+
+ lcol[0] = lt->ob.emr * falloff;
+ lcol[1] = lt->ob.emg * falloff;
+ lcol[2] = lt->ob.emb * falloff;
+
+ if((ndotl = hit->nx * ldir[0] + hit->ny * ldir[1] + hit->nz * ldir[2]) < 0.0f) {
+ ndotl = 0.0f;
+ }
+
+ dcol[0] += o->ob.r * lcol[0] * ndotl;
+ dcol[1] += o->ob.g * lcol[1] * ndotl;
+ dcol[2] += o->ob.b * lcol[2] * ndotl;
+
+ if(o->ob.roughness < 1.0f) {
+ float gloss = 1.0f - o->ob.roughness;
+
+ hdir[0] = ldir[0] - ray->dx;
+ hdir[1] = ldir[1] - ray->dy;
+ hdir[2] = ldir[2] - ray->dz;
+ if((len = sqrt(hdir[0] * hdir[0] + hdir[1] * hdir[1] + hdir[2] * hdir[2])) != 0.0f) {
+ float s = 1.0f / len;
+ hdir[0] *= s;
+ hdir[1] *= s;
+ hdir[2] *= s;
+ }
+
+ if((ndoth = hit->nx * hdir[0] + hit->ny * hdir[1] + hit->nz * hdir[2]) < 0.0f) {
+ ndoth = 0.0f;
+ }
+ spec = gloss * pow(ndoth, 100.0f * gloss);
+
+ if(o->ob.metallic) {
+ lcol[0] *= o->ob.r;
+ lcol[1] *= o->ob.g;
+ lcol[2] *= o->ob.b;
+ }
+ scol[0] += lcol[0] * spec;
+ scol[1] += lcol[1] * spec;
+ scol[2] += lcol[2] * spec;
+ }
+ }
+
+ lt = lt->ob.plt_next;
+ }
+
+ col[0] = dcol[0] + scol[0];
+ col[1] = dcol[1] + scol[1];
+ col[2] = dcol[2] + scol[2];
+}
+
+static void background(float *col, struct ray *ray)
+{
+ col[0] = col[1] = col[2] = 0.0f;
+}
+
+static int find_intersection(struct ray *ray, struct hit *best)
+{
+ int idx = 0;
+ csg_object *o;
+ struct hinterv *hit, *it;
+
+ best->t = FLT_MAX;
+ best->o = 0;
+
+ o = oblist;
+ while(o) {
+ if((hit = ray_intersect(ray, o))) {
+ it = hit;
+ while(it) {
+ if(it->end[0].t > 1e-6) {
+ idx = 0;
+ break;
+ }
+ if(it->end[1].t > 1e-6) {
+ idx = 1;
+ break;
+ }
+ it = it->next;
+ }
+
+ if(it && it->end[idx].t < best->t) {
+ *best = it->end[idx];
+ }
+ }
+ free_hit_list(hit);
+ o = o->ob.next;
+ }
+
+ return best->o != 0;
+}
+
+static csg_object *load_object(struct ts_node *node)
+{
+ float *avec;
+ struct ts_node *c;
+ csg_object *sub, *o = 0, *olist = 0, *otail = 0;
+ int num_subobj = 0, is_csgop = 0;
+
+ if(strcmp(node->name, "null") == 0) {
+ if(!(o = csg_null(0, 0, 0))) {
+ goto err;
+ }
+
+ } else if(strcmp(node->name, "sphere") == 0) {
+ float rad = ts_get_attr_num(node, "radius", 1.0f);
+ if(!(o = csg_sphere(0, 0, 0, rad))) {
+ goto err;
+ }
+
+ } else if(strcmp(node->name, "cylinder") == 0) {
+ float rad = ts_get_attr_num(node, "radius", 1.0f);
+ float height = ts_get_attr_num(node, "height", 1.0f);
+ if(!(o = csg_cylinder(0, -height/2.0f, 0, 0, height/2.0f, 0, rad))) {
+ goto err;
+ }
+
+ } else if(strcmp(node->name, "plane") == 0) {
+ static float def_norm[] = {0, 1, 0};
+ float *norm = ts_get_attr_vec(node, "normal", def_norm);
+ if(!(o = csg_plane(0, 0, 0, norm[0], norm[1], norm[2]))) {
+ goto err;
+ }
+
+ } else if(strcmp(node->name, "box") == 0) {
+ static float def_sz[] = {1, 1, 1};
+ float *sz = ts_get_attr_vec(node, "size", def_sz);
+ if(!(o = csg_box(0, 0, 0, sz[0], sz[1], sz[2]))) {
+ goto err;
+ }
+
+ } else if(strcmp(node->name, "union") == 0) {
+ if(!(o = csg_union(0, 0))) {
+ goto err;
+ }
+ is_csgop = 1;
+
+ } else if(strcmp(node->name, "intersect") == 0) {
+ if(!(o = csg_intersection(0, 0))) {
+ goto err;
+ }
+ is_csgop = 1;
+
+ } else if(strcmp(node->name, "subtract") == 0) {
+ if(!(o = csg_subtraction(0, 0))) {
+ goto err;
+ }
+ is_csgop = 1;
+
+ } else {
+ goto err;
+ }
+
+ if(is_csgop) {
+ c = node->child_list;
+ while(c) {
+ if((sub = load_object(c))) {
+ if(olist) {
+ otail->ob.next = sub;
+ otail = sub;
+ } else {
+ olist = otail = sub;
+ }
+ ++num_subobj;
+ }
+ c = c->next;
+ }
+
+ if(num_subobj != 2) {
+ goto err;
+ }
+ o->un.a = olist;
+ o->un.b = olist->ob.next;
+ olist->ob.next = 0;
+ }
+
+ if((avec = ts_get_attr_vec(node, "position", 0))) {
+ csg_translate(o, avec[0], avec[1], avec[2]);
+ }
+ if((avec = ts_get_attr_vec(node, "rotaxis", 0))) {
+ csg_rotate(o, ts_get_attr_num(node, "rotangle", 0.0f), avec[0], avec[1], avec[2]);
+ }
+ if((avec = ts_get_attr_vec(node, "scaling", 0))) {
+ csg_scale(o, avec[0], avec[1], avec[2]);
+ }
+ if((avec = ts_get_attr_vec(node, "target", 0))) {
+ /* don't move this before position */
+ float def_up[] = {0, 1, 0};
+ float *up = ts_get_attr_vec(node, "up", def_up);
+ float x = o->ob.xform[12];
+ float y = o->ob.xform[13];
+ float z = o->ob.xform[14];
+ csg_lookat(o, x, y, z, avec[0], avec[1], avec[2], up[0], up[1], up[2]);
+ }
+
+ if((avec = ts_get_attr_vec(node, "color", 0))) {
+ csg_color(o, avec[0], avec[1], avec[2]);
+ }
+ if((avec = ts_get_attr_vec(node, "emission", 0))) {
+ csg_emission(o, avec[0], avec[1], avec[2]);
+ }
+
+ csg_roughness(o, ts_get_attr_num(node, "roughness", o->ob.roughness));
+ csg_opacity(o, ts_get_attr_num(node, "opacity", o->ob.opacity));
+ csg_metallic(o, ts_get_attr_int(node, "metallic", o->ob.metallic));
+
+ return o;
+
+err:
+ csg_free_object(o);
+ while(olist) {
+ o = olist;
+ olist = olist->ob.next;
+ csg_free_object(o);
+ }
+ return 0;