nuclear@8: #include <assert.h>
nuclear@6: #include "rt.h"
nuclear@8: #include "erebus_impl.h"
nuclear@8: 
nuclear@8: #define MAX_ITER	8
nuclear@6: 
nuclear@6: Color ray_trace(const Ray &ray, const Scene *scn, int iter)
nuclear@6: {
nuclear@6: 	RayHit hit;
nuclear@6: 	if(!(scn->intersect(ray, &hit))) {
nuclear@8: 		return scn->get_env_color(ray);
nuclear@6: 	}
nuclear@6: 
nuclear@8: 	return shade(hit, scn, iter);
nuclear@6: }
nuclear@6: 
nuclear@8: Color shade(const RayHit &hit, const Scene *scn, int iter)
nuclear@6: {
nuclear@8: 	assert(hit.obj->get_type() == ObjType::geom);
nuclear@8: 	const GeomObject *obj = (const GeomObject*)hit.obj;
nuclear@8: 	const Material *mtl = &obj->mtl;
nuclear@8: 	const Reflectance *brdf = obj->brdf;
nuclear@8: 	const Ray &ray = hit.world_ray;
nuclear@8: 
nuclear@8: 	Vector3 norm = obj->calc_normal(hit);
nuclear@8: 	Vector2 texcoords = obj->calc_texcoords(hit);
nuclear@8: 
nuclear@8: 	Color color = mtl->get_attrib_color("albedo", texcoords.x, texcoords.y);
nuclear@8: 	Color res = mtl->get_attrib_color("emissive") + color * scn->get_env().ambient;
nuclear@8: 
nuclear@8: 	Vector3 sample_dir;
nuclear@8: 	float prob = brdf->sample(norm, -hit.world_ray.dir, &sample_dir);
nuclear@8: 	if(iter < MAX_ITER && randf() <= prob) {
nuclear@8: 		Ray sample_ray;
nuclear@8: 		sample_ray.origin = ray.origin + ray.dir * hit.dist;
nuclear@8: 		sample_ray.dir = sample_dir;
nuclear@8: 
nuclear@8: 		res += ray_trace(sample_ray, scn, iter + 1) * color;
nuclear@8: 	}
nuclear@8: 	return res;
nuclear@6: }