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nuclear@12
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1 /* vim: set ft=opencl:ts=4:sw=4 */
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nuclear@12
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2
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nuclear@2
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3 struct RendInfo {
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nuclear@2
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4 int xsz, ysz;
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nuclear@9
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5 int num_faces, num_lights;
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nuclear@2
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6 int max_iter;
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nuclear@16
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7 float4 ambient;
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nuclear@2
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8 };
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nuclear@2
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9
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nuclear@9
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10 struct Vertex {
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nuclear@2
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11 float4 pos;
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nuclear@9
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12 float4 normal;
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nuclear@12
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13 float4 tex;
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nuclear@12
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14 float4 padding;
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nuclear@9
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15 };
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nuclear@9
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16
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nuclear@9
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17 struct Face {
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nuclear@9
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18 struct Vertex v[3];
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nuclear@9
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19 float4 normal;
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nuclear@9
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20 int matid;
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nuclear@12
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21 int padding[3];
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nuclear@9
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22 };
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nuclear@9
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23
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nuclear@9
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24 struct Material {
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nuclear@5
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25 float4 kd, ks;
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nuclear@9
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26 float kr, kt;
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nuclear@9
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27 float spow;
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nuclear@12
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28 float padding;
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nuclear@2
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29 };
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nuclear@2
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30
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nuclear@3
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31 struct Light {
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nuclear@3
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32 float4 pos, color;
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nuclear@3
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33 };
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nuclear@3
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34
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nuclear@2
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35 struct Ray {
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nuclear@2
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36 float4 origin, dir;
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nuclear@2
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37 };
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nuclear@2
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38
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nuclear@2
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39 struct SurfPoint {
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nuclear@2
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40 float t;
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nuclear@12
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41 float4 pos, norm, dbg;
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nuclear@9
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42 global const struct Face *obj;
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nuclear@19
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43 struct Material mat;
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nuclear@2
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44 };
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nuclear@2
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45
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nuclear@16
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46 struct Scene {
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nuclear@16
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47 float4 ambient;
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nuclear@16
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48 global const struct Face *faces;
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nuclear@16
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49 int num_faces;
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nuclear@16
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50 global const struct Light *lights;
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nuclear@16
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51 int num_lights;
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nuclear@16
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52 global const struct Material *matlib;
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nuclear@16
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53 };
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nuclear@2
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54
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nuclear@16
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55 #define MIN_ENERGY 0.001
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nuclear@21
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56 #define EPSILON 1e-5
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nuclear@16
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57
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nuclear@16
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58 float4 shade(struct Ray ray, struct Scene *scn, const struct SurfPoint *sp);
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nuclear@16
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59 bool find_intersection(struct Ray ray, const struct Scene *scn, struct SurfPoint *sp);
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nuclear@9
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60 bool intersect(struct Ray ray, global const struct Face *face, struct SurfPoint *sp);
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nuclear@16
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61
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nuclear@8
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62 float4 reflect(float4 v, float4 n);
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nuclear@8
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63 float4 transform(float4 v, global const float *xform);
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nuclear@16
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64 void transform_ray(struct Ray *ray, global const float *xform, global const float *invtrans);
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nuclear@12
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65 float4 calc_bary(float4 pt, global const struct Face *face, float4 norm);
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nuclear@19
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66 float mean(float4 v);
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nuclear@4
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67
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nuclear@4
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68 kernel void render(global float4 *fb,
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nuclear@4
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69 global const struct RendInfo *rinf,
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nuclear@9
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70 global const struct Face *faces,
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nuclear@9
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71 global const struct Material *matlib,
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nuclear@4
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72 global const struct Light *lights,
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nuclear@7
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73 global const struct Ray *primrays,
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nuclear@12
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74 global const float *xform,
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nuclear@20
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75 global const float *invtrans)
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nuclear@2
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76 {
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nuclear@2
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77 int idx = get_global_id(0);
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nuclear@2
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78
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nuclear@16
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79 struct Scene scn;
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nuclear@16
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80 scn.ambient = rinf->ambient;
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nuclear@16
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81 scn.faces = faces;
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nuclear@16
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82 scn.num_faces = rinf->num_faces;
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nuclear@16
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83 scn.lights = lights;
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nuclear@16
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84 scn.num_lights = rinf->num_lights;
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nuclear@16
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85 scn.matlib = matlib;
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nuclear@8
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86
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nuclear@16
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87 struct Ray ray = primrays[idx];
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nuclear@16
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88 transform_ray(&ray, xform, invtrans);
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nuclear@4
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89
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nuclear@19
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90 float4 pixel = (float4)(0, 0, 0, 0);
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nuclear@19
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91 float4 energy = (float4)(1.0, 1.0, 1.0, 1.0);
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nuclear@19
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92 int iter = 0;
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nuclear@19
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93
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nuclear@19
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94 while(iter++ < rinf->max_iter && mean(energy) > MIN_ENERGY) {
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nuclear@19
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95 struct SurfPoint sp;
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nuclear@19
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96 if(find_intersection(ray, &scn, &sp)) {
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nuclear@19
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97 pixel += shade(ray, &scn, &sp) * energy;
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nuclear@19
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98
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nuclear@19
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99 float4 refl_col = sp.mat.ks * sp.mat.kr;
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nuclear@19
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100
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nuclear@19
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101 ray.origin = sp.pos;
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nuclear@19
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102 ray.dir = reflect(-ray.dir, sp.norm);
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nuclear@19
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103
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nuclear@19
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104 energy *= sp.mat.ks * sp.mat.kr;
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nuclear@19
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105 } else {
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nuclear@19
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106 iter = INT_MAX - 1; // to break out of the loop
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nuclear@19
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107 }
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nuclear@17
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108 }
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nuclear@19
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109
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nuclear@19
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110 fb[idx] = pixel;
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nuclear@4
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111 }
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nuclear@4
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112
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nuclear@16
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113 float4 shade(struct Ray ray, struct Scene *scn, const struct SurfPoint *sp)
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nuclear@16
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114 {
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nuclear@16
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115 float4 norm = sp->norm;
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nuclear@12
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116 bool entering = true;
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nuclear@12
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117
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nuclear@12
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118 if(dot(ray.dir, norm) >= 0.0) {
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nuclear@12
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119 norm = -norm;
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nuclear@12
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120 entering = false;
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nuclear@12
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121 }
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nuclear@12
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122
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nuclear@19
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123 float4 dcol = scn->ambient * sp->mat.kd;
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nuclear@8
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124 float4 scol = (float4)(0, 0, 0, 0);
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nuclear@5
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125
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nuclear@16
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126 for(int i=0; i<scn->num_lights; i++) {
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nuclear@16
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127 float4 ldir = scn->lights[i].pos - sp->pos;
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nuclear@5
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128
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nuclear@16
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129 struct Ray shadowray;
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nuclear@16
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130 shadowray.origin = sp->pos;
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nuclear@16
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131 shadowray.dir = ldir;
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nuclear@5
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132
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nuclear@16
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133 if(!find_intersection(shadowray, scn, 0)) {
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nuclear@16
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134 ldir = normalize(ldir);
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nuclear@16
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135 float4 vdir = -normalize(ray.dir);
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nuclear@16
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136 float4 vref = reflect(vdir, norm);
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nuclear@16
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137
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nuclear@16
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138 float diff = fmax(dot(ldir, norm), 0.0f);
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nuclear@19
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139 dcol += sp->mat.kd * diff * scn->lights[i].color;
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nuclear@16
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140
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nuclear@20
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141 float spec = powr(fmax(dot(ldir, vref), 0.0f), sp->mat.spow);
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nuclear@20
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142 scol += sp->mat.ks * spec * scn->lights[i].color;
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nuclear@16
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143 }
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nuclear@16
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144 }
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nuclear@16
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145
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nuclear@8
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146 return dcol + scol;
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nuclear@2
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147 }
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nuclear@2
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148
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nuclear@16
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149
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nuclear@16
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150 bool find_intersection(struct Ray ray, const struct Scene *scn, struct SurfPoint *spres)
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nuclear@12
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151 {
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nuclear@16
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152 struct SurfPoint sp, sp0;
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nuclear@16
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153 sp0.t = 1.0;
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nuclear@16
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154 sp0.obj = 0;
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nuclear@16
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155
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nuclear@16
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156 for(int i=0; i<scn->num_faces; i++) {
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nuclear@16
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157 if(intersect(ray, scn->faces + i, &sp) && sp.t < sp0.t) {
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nuclear@16
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158 sp0 = sp;
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nuclear@16
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159 }
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nuclear@16
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160 }
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nuclear@16
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161
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nuclear@16
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162 if(!sp0.obj) {
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nuclear@16
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163 return false;
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nuclear@16
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164 }
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nuclear@16
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165
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nuclear@16
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166 if(spres) {
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nuclear@16
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167 *spres = sp0;
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nuclear@19
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168 spres->mat = scn->matlib[sp0.obj->matid];
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nuclear@16
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169 }
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nuclear@16
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170 return true;
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nuclear@12
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171 }
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nuclear@12
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172
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nuclear@16
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173 bool intersect(struct Ray ray, global const struct Face *face, struct SurfPoint *sp)
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nuclear@2
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174 {
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nuclear@12
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175 float4 origin = ray.origin;
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nuclear@12
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176 float4 dir = ray.dir;
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nuclear@12
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177 float4 norm = face->normal;
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nuclear@12
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178
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nuclear@16
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179 float ndotdir = dot(dir, norm);
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nuclear@12
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180
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nuclear@9
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181 if(fabs(ndotdir) <= EPSILON) {
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nuclear@9
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182 return false;
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nuclear@9
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183 }
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nuclear@2
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184
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nuclear@9
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185 float4 pt = face->v[0].pos;
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nuclear@12
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186 float4 vec = pt - origin;
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nuclear@2
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187
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nuclear@16
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188 float ndotvec = dot(norm, vec);
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nuclear@9
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189 float t = ndotvec / ndotdir;
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nuclear@2
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190
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nuclear@2
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191 if(t < EPSILON || t > 1.0) {
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nuclear@2
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192 return false;
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nuclear@2
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193 }
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nuclear@12
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194 pt = origin + dir * t;
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nuclear@9
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195
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nuclear@12
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196
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nuclear@12
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197 float4 bc = calc_bary(pt, face, norm);
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nuclear@9
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198 float bc_sum = bc.x + bc.y + bc.z;
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nuclear@9
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199
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nuclear@20
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200 if(bc_sum < 1.0 - EPSILON || bc_sum > 1.0 + EPSILON) {
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nuclear@9
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201 return false;
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nuclear@12
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202 bc *= 1.2;
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nuclear@9
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203 }
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nuclear@2
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204
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nuclear@2
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205 sp->t = t;
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nuclear@9
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206 sp->pos = pt;
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nuclear@21
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207 sp->norm = normalize(face->v[0].normal * bc.x + face->v[1].normal * bc.y + face->v[2].normal * bc.z);
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nuclear@9
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208 sp->obj = face;
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nuclear@12
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209 sp->dbg = bc;
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nuclear@2
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210 return true;
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nuclear@2
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211 }
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nuclear@5
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212
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nuclear@8
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213 float4 reflect(float4 v, float4 n)
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nuclear@5
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214 {
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nuclear@12
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215 float4 res = 2.0f * dot(v, n) * n - v;
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nuclear@12
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216 return res;
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nuclear@5
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217 }
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nuclear@8
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218
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nuclear@8
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219 float4 transform(float4 v, global const float *xform)
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nuclear@8
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220 {
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nuclear@8
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221 float4 res;
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nuclear@8
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222 res.x = v.x * xform[0] + v.y * xform[4] + v.z * xform[8] + xform[12];
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nuclear@8
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223 res.y = v.x * xform[1] + v.y * xform[5] + v.z * xform[9] + xform[13];
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nuclear@8
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224 res.z = v.x * xform[2] + v.y * xform[6] + v.z * xform[10] + xform[14];
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nuclear@12
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225 res.w = 0.0;
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nuclear@8
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226 return res;
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nuclear@8
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227 }
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nuclear@8
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228
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nuclear@16
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229 void transform_ray(struct Ray *ray, global const float *xform, global const float *invtrans)
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nuclear@8
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230 {
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nuclear@16
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231 ray->origin = transform(ray->origin, xform);
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nuclear@16
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232 ray->dir = transform(ray->dir, invtrans);
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nuclear@8
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233 }
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nuclear@9
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234
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nuclear@12
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235 float4 calc_bary(float4 pt, global const struct Face *face, float4 norm)
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nuclear@9
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236 {
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nuclear@12
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237 float4 bc = (float4)(0, 0, 0, 0);
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nuclear@9
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238
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nuclear@12
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239 // calculate area of the whole triangle
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nuclear@12
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240 float4 v1 = face->v[1].pos - face->v[0].pos;
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nuclear@12
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241 float4 v2 = face->v[2].pos - face->v[0].pos;
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nuclear@12
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242 float4 xv1v2 = cross(v1, v2);
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nuclear@12
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243
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nuclear@16
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244 float area = fabs(dot(xv1v2, norm)) * 0.5;
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nuclear@9
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245 if(area < EPSILON) {
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nuclear@9
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246 return bc;
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nuclear@9
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247 }
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nuclear@9
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248
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nuclear@9
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249 float4 pv0 = face->v[0].pos - pt;
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nuclear@9
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250 float4 pv1 = face->v[1].pos - pt;
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nuclear@9
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251 float4 pv2 = face->v[2].pos - pt;
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nuclear@9
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252
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nuclear@12
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253 // calculate the area of each sub-triangle
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nuclear@12
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254 float4 x12 = cross(pv1, pv2);
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nuclear@12
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255 float4 x20 = cross(pv2, pv0);
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nuclear@12
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256 float4 x01 = cross(pv0, pv1);
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nuclear@12
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257
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nuclear@16
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258 float a0 = fabs(dot(x12, norm)) * 0.5;
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nuclear@16
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259 float a1 = fabs(dot(x20, norm)) * 0.5;
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nuclear@16
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260 float a2 = fabs(dot(x01, norm)) * 0.5;
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nuclear@9
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261
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nuclear@9
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262 bc.x = a0 / area;
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nuclear@9
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263 bc.y = a1 / area;
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nuclear@9
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264 bc.z = a2 / area;
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nuclear@9
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265 return bc;
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nuclear@9
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266 }
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nuclear@19
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267
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nuclear@19
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268 float mean(float4 v)
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nuclear@19
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269 {
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nuclear@19
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270 return native_divide(v.x + v.y + v.z, 3.0);
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nuclear@19
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271 }
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