nuclear@1: /*
nuclear@1: libvmath - a vector math library
nuclear@1: Copyright (C) 2004-2011 John Tsiombikas <nuclear@member.fsf.org>
nuclear@1: 
nuclear@1: This program is free software: you can redistribute it and/or modify
nuclear@1: it under the terms of the GNU Lesser General Public License as published
nuclear@1: by the Free Software Foundation, either version 3 of the License, or
nuclear@1: (at your option) any later version.
nuclear@1: 
nuclear@1: This program is distributed in the hope that it will be useful,
nuclear@1: but WITHOUT ANY WARRANTY; without even the implied warranty of
nuclear@1: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
nuclear@1: GNU Lesser General Public License for more details.
nuclear@1: 
nuclear@1: You should have received a copy of the GNU Lesser General Public License
nuclear@1: along with this program.  If not, see <http://www.gnu.org/licenses/>.
nuclear@1: */
nuclear@1: 
nuclear@1: #include "ray.h"
nuclear@1: #include "vector.h"
nuclear@1: 
nuclear@1: ray_t ray_transform(ray_t r, mat4_t xform)
nuclear@1: {
nuclear@1: 	mat4_t upper;
nuclear@1: 	vec3_t dir;
nuclear@1: 
nuclear@1: 	m4_copy(upper, xform);
nuclear@1: 	upper[0][3] = upper[1][3] = upper[2][3] = upper[3][0] = upper[3][1] = upper[3][2] = 0.0;
nuclear@1: 	upper[3][3] = 1.0;
nuclear@1: 
nuclear@1: 	dir = v3_sub(r.dir, r.origin);
nuclear@1: 	dir = v3_transform(dir, upper);
nuclear@1: 	r.origin = v3_transform(r.origin, xform);
nuclear@1: 	r.dir = v3_add(dir, r.origin);
nuclear@1: 	return r;
nuclear@1: }