1 /*

2 libvmath - a vector math library

3 Copyright (C) 2004-2011 John Tsiombikas <nuclear@member.fsf.org>

4

5 This program is free software: you can redistribute it and/or modify

6 it under the terms of the GNU Lesser General Public License as published

7 by the Free Software Foundation, either version 3 of the License, or

8 (at your option) any later version.

9

10 This program is distributed in the hope that it will be useful,

11 but WITHOUT ANY WARRANTY; without even the implied warranty of

12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

13 GNU Lesser General Public License for more details.

14

15 You should have received a copy of the GNU Lesser General Public License

16 along with this program. If not, see <http://www.gnu.org/licenses/>.

17 */

18

19 #include "ray.h"

20 #include "vector.h"

21

22 ray_t ray_transform(ray_t r, mat4_t xform)

23 {

24 mat4_t upper;

25 vec3_t dir;

26

27 m4_copy(upper, xform);

28 upper[0][3] = upper[1][3] = upper[2][3] = upper[3][0] = upper[3][1] = upper[3][2] = 0.0;

29 upper[3][3] = 1.0;

30

31 dir = v3_sub(r.dir, r.origin);

32 dir = v3_transform(dir, upper);

33 r.origin = v3_transform(r.origin, xform);

34 r.dir = v3_add(dir, r.origin);

35 return r;

36 }