nuclear@39: /*
nuclear@39: libvmath - a vector math library
nuclear@39: Copyright (C) 2004-2011 John Tsiombikas <nuclear@member.fsf.org>
nuclear@39: 
nuclear@39: This program is free software: you can redistribute it and/or modify
nuclear@39: it under the terms of the GNU Lesser General Public License as published
nuclear@39: by the Free Software Foundation, either version 3 of the License, or
nuclear@39: (at your option) any later version.
nuclear@39: 
nuclear@39: This program is distributed in the hope that it will be useful,
nuclear@39: but WITHOUT ANY WARRANTY; without even the implied warranty of
nuclear@39: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
nuclear@39: GNU Lesser General Public License for more details.
nuclear@39: 
nuclear@39: You should have received a copy of the GNU Lesser General Public License
nuclear@39: along with this program.  If not, see <http://www.gnu.org/licenses/>.
nuclear@39: */
nuclear@39: 
nuclear@29: #ifdef __cplusplus
nuclear@29: extern "C" {
nuclear@29: #endif	/* __cplusplus */
nuclear@29: 
nuclear@29: static inline ray_t ray_cons(vec3_t origin, vec3_t dir)
nuclear@29: {
nuclear@29: 	ray_t r;
nuclear@29: 	r.origin = origin;
nuclear@29: 	r.dir = dir;
nuclear@29: 	return r;
nuclear@29: }
nuclear@29: 
nuclear@29: #ifdef __cplusplus
nuclear@29: }
nuclear@29: 
nuclear@29: inline Ray reflect_ray(const Ray &inray, const Vector3 &norm)
nuclear@29: {
nuclear@29: 	Ray ray = inray;
nuclear@29: 	ray.iter--;
nuclear@29: 	ray.dir = ray.dir.reflection(norm);
nuclear@29: 	return ray;
nuclear@29: }
nuclear@29: 
nuclear@29: inline Ray refract_ray(const Ray &inray, const Vector3 &norm, scalar_t mat_ior, bool entering, scalar_t ray_mag)
nuclear@29: {
nuclear@29: 	Ray ray = inray;
nuclear@29: 	ray.iter--;
nuclear@29: 
nuclear@29: 	scalar_t ior = ray.calc_ior(entering, mat_ior);
nuclear@29: 	
nuclear@29: 	if(entering) {
nuclear@29: 		ray.enter(mat_ior);
nuclear@29: 	} else {
nuclear@29: 		ray.leave();
nuclear@29: 	}
nuclear@29: 
nuclear@29: 	if(ray_mag < 0.0) {
nuclear@29: 		ray_mag = ray.dir.length();
nuclear@29: 	}
nuclear@29: 	ray.dir = (ray.dir / ray_mag).refraction(norm, ior) * ray_mag;
nuclear@29: 
nuclear@29: 	/* check TIR */
nuclear@29: 	if(dot_product(ray.dir, norm) > 0.0) {
nuclear@29: 		if(entering) {
nuclear@29: 			ray.leave();
nuclear@29: 		} else {
nuclear@29: 			ray.enter(mat_ior);
nuclear@29: 		}
nuclear@29: 	}
nuclear@29: 	return ray;
nuclear@29: }
nuclear@29: #endif	/* __cplusplus */