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 #ifdef __cplusplus

20 extern "C" {

21 #endif /* __cplusplus */

22

23 static inline ray_t ray_cons(vec3_t origin, vec3_t dir)

24 {

25 ray_t r;

26 r.origin = origin;

27 r.dir = dir;

28 return r;

29 }

30

31 #ifdef __cplusplus

32 }

33

34 inline Ray reflect_ray(const Ray &inray, const Vector3 &norm)

35 {

36 Ray ray = inray;

37 ray.iter--;

38 ray.dir = ray.dir.reflection(norm);

39 return ray;

40 }

41

42 inline Ray refract_ray(const Ray &inray, const Vector3 &norm, scalar_t mat_ior, bool entering, scalar_t ray_mag)

43 {

44 Ray ray = inray;

45 ray.iter--;

46

47 scalar_t ior = ray.calc_ior(entering, mat_ior);

48

49 if(entering) {

50 ray.enter(mat_ior);

51 } else {

52 ray.leave();

53 }

54

55 if(ray_mag < 0.0) {

56 ray_mag = ray.dir.length();

57 }

58 ray.dir = (ray.dir / ray_mag).refraction(norm, ior) * ray_mag;

59

60 /* check TIR */

61 if(dot_product(ray.dir, norm) > 0.0) {

62 if(entering) {

63 ray.leave();

64 } else {

65 ray.enter(mat_ior);

66 }

67 }

68 return ray;

69 }

70 #endif /* __cplusplus */