1 #include <assert.h>

2 #include <float.h>

3 #include "raytrace.h"

4 #include "rayzor.h"

5 #include "scene.h"

6 #include "logger.h"

7

8 Vector3 ray_trace(const Ray &ray, int iter)

9 {

10 RayHit hit;

11 if(!scene->intersect(ray, &hit)) {

12 return scene->get_background(ray);

13 }

14

15 return shade(hit, iter);

16 }

17

18 static inline float positive(float x)

19 {

20 return x < 0.0f ? 0.0f : x;

21 }

22

23 Vector3 shade(const RayHit &hit, int iter)

24 {

25 Vector3 pos = hit.ray.origin + hit.ray.dir * hit.dist;

26 Vector3 norm = hit.obj->hit_normal(hit);

27 norm = normalize(transform(normal_matrix(hit.obj->get_matrix()), norm));

28 Vector3 vdir = -normalize(hit.ray.dir);

29

30 Vector3 color = scene->get_ambient();

31

32 const Vector3 &kd = hit.obj->mtl.diffuse;

33 const Vector3 &ks = hit.obj->mtl.specular;

34 float roughness = hit.obj->mtl.roughness;

35

36 int num_lights = scene->get_light_count();

37 for(int i=0; i<num_lights; i++) {

38 const Light *lt = scene->get_light(i);

39 Vector3 ldir = lt->get_position() - pos;

40 Vector3 lcol = lt->get_color(pos);

41

42 RayHit hit;

43 if(!scene->intersect(Ray(pos, ldir), &hit) || hit.dist > 1.0) {

44 // if we can see the light, calculate and add its contribution

45 ldir.normalize();

46 float ndotl = positive(dot(norm, ldir));

47 Vector3 diffuse = kd * lcol * ndotl;

48

49 Vector3 hdir = normalize(ldir + vdir);

50 float ndoth = positive(dot(norm, hdir));

51 Vector3 specular = ks * lcol * pow(ndoth, roughness * 128.0);

52

53 color = color + lerp(specular, diffuse, roughness);

54 }

55 }

56

57 return color;

58 }