nuclear@22: #include <assert.h>
nuclear@22: #include <float.h>
nuclear@22: #include "raytrace.h"
nuclear@22: #include "rayzor.h"
nuclear@22: #include "scene.h"
nuclear@22: #include "logger.h"
nuclear@22: 
nuclear@22: Vector3 ray_trace(const Ray &ray, int iter)
nuclear@22: {
nuclear@22: 	RayHit hit;
nuclear@22: 	if(!scene->intersect(ray, &hit)) {
nuclear@22: 		return scene->get_background(ray);
nuclear@22: 	}
nuclear@22: 
nuclear@22: 	return shade(hit, iter);
nuclear@22: }
nuclear@22: 
nuclear@22: static inline float positive(float x)
nuclear@22: {
nuclear@22: 	return x < 0.0f ? 0.0f : x;
nuclear@22: }
nuclear@22: 
nuclear@22: Vector3 shade(const RayHit &hit, int iter)
nuclear@22: {
nuclear@22: 	const Material &mtl = hit.obj->mtl;
nuclear@22: 
nuclear@22: 	Vector3 pos = hit.ray.origin + hit.ray.dir * hit.dist;
nuclear@22: 	Vector3 norm = hit.obj->hit_normal(hit);
nuclear@22: 	norm = normalize(transform(normal_matrix(hit.obj->get_matrix()), norm));
nuclear@22: 	Vector3 vdir = -normalize(hit.ray.dir);
nuclear@22: 
nuclear@22: 	float ior = mtl.ior;
nuclear@22: 
nuclear@22: 	if(dot(norm, hit.ray.dir) > 0.0) {
nuclear@22: 		norm = -norm;
nuclear@22: 		ior = 1.0 / mtl.ior;
nuclear@22: 	}
nuclear@22: 
nuclear@22: 	Vector3 color = scene->get_ambient();
nuclear@22: 
nuclear@22: 	// for each light, calculate local illumination
nuclear@22: 	int num_lights = scene->get_light_count();
nuclear@22: 	for(int i=0; i<num_lights; i++) {
nuclear@22: 		const Light *lt = scene->get_light(i);
nuclear@22: 		Vector3 ldir = lt->get_position() - pos;
nuclear@22: 		Vector3 lcol = lt->get_color(pos);
nuclear@22: 
nuclear@22: 		RayHit hit;
nuclear@22: 		if(!scene->intersect(Ray(pos, ldir), &hit) || hit.dist > 1.0) {
nuclear@22: 			// if we can see the light, calculate and add its contribution
nuclear@22: 			ldir.normalize();
nuclear@22: 			float ndotl = positive(dot(norm, ldir));
nuclear@22: 			Vector3 diffuse = mtl.diffuse * lcol * ndotl;
nuclear@22: 
nuclear@22: 			Vector3 hdir = normalize(ldir + vdir);
nuclear@22: 			float ndoth = positive(dot(norm, hdir));
nuclear@22: 			Vector3 specular = mtl.specular * lcol * pow(ndoth, mtl.roughness * 128.0);
nuclear@22: 
nuclear@22: 			color = color + lerp(specular, diffuse, mtl.roughness);
nuclear@22: 		}
nuclear@22: 	}
nuclear@22: 
nuclear@22: 	if(mtl.reflect > 1e-4 && iter < 6) {
nuclear@22: 		Ray reflray(pos, reflect(vdir, norm));
nuclear@22: 
nuclear@22: 		Vector3 rcol = ray_trace(reflray, iter + 1) * mtl.specular * mtl.reflect;
nuclear@22: 		color = color + rcol;
nuclear@22: 	}
nuclear@22: 
nuclear@22: 	if(mtl.refract > 1e-4 && iter < 6) {
nuclear@22: 		Ray refrray(pos, refract(vdir, norm,  ior));
nuclear@22: 
nuclear@22: 		Vector3 rcol = ray_trace(refrray, iter + 1) * mtl.specular * mtl.refract;
nuclear@22: 		color = color + rcol;
nuclear@22: 	}
nuclear@22: 
nuclear@22: 	return color;
nuclear@22: }