clray

annotate rt.cl @ 8:deaf85acf6af

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interactive spheres
author John Tsiombikas <nuclear@member.fsf.org>
date Fri, 23 Jul 2010 19:48:43 +0100
parents 575383f3a239
children a09622aaa043
rev   line source
nuclear@2 1 struct RendInfo {
nuclear@2 2 int xsz, ysz;
nuclear@3 3 int num_sph, num_lights;
nuclear@2 4 int max_iter;
nuclear@2 5 };
nuclear@2 6
nuclear@2 7 struct Sphere {
nuclear@2 8 float4 pos;
nuclear@5 9 float4 kd, ks;
nuclear@2 10 float radius;
nuclear@4 11 float spow, kr, kt;
nuclear@2 12 };
nuclear@2 13
nuclear@3 14 struct Light {
nuclear@3 15 float4 pos, color;
nuclear@3 16 };
nuclear@3 17
nuclear@2 18 struct Ray {
nuclear@2 19 float4 origin, dir;
nuclear@2 20 };
nuclear@2 21
nuclear@2 22 struct SurfPoint {
nuclear@2 23 float t;
nuclear@8 24 float4 pos, norm;
nuclear@4 25 global const struct Sphere *obj;
nuclear@2 26 };
nuclear@2 27
nuclear@2 28 #define EPSILON 1e-6
nuclear@2 29
nuclear@5 30 float4 shade(struct Ray ray, struct SurfPoint sp,
nuclear@5 31 global const struct Light *lights, int num_lights);
nuclear@4 32 bool intersect(struct Ray ray, global const struct Sphere *sph, struct SurfPoint *sp);
nuclear@8 33 float4 reflect(float4 v, float4 n);
nuclear@8 34 float4 transform(float4 v, global const float *xform);
nuclear@8 35 struct Ray transform_ray(global const struct Ray *ray, global const float *xform);
nuclear@2 36
nuclear@4 37
nuclear@4 38 kernel void render(global float4 *fb,
nuclear@4 39 global const struct RendInfo *rinf,
nuclear@4 40 global const struct Sphere *sphlist,
nuclear@4 41 global const struct Light *lights,
nuclear@7 42 global const struct Ray *primrays,
nuclear@8 43 global const float *xform)
nuclear@2 44 {
nuclear@2 45 int idx = get_global_id(0);
nuclear@2 46
nuclear@8 47 struct Ray ray = transform_ray(primrays + idx, xform);
nuclear@8 48
nuclear@4 49 struct SurfPoint sp, sp0;
nuclear@4 50 sp0.t = FLT_MAX;
nuclear@5 51 sp0.obj = 0;
nuclear@4 52
nuclear@4 53 for(int i=0; i<rinf->num_sph; i++) {
nuclear@5 54 if(intersect(ray, sphlist + i, &sp) && sp.t < sp0.t) {
nuclear@4 55 sp0 = sp;
nuclear@4 56 }
nuclear@2 57 }
nuclear@3 58
nuclear@5 59 if(sp0.obj) {
nuclear@5 60 fb[idx] = shade(ray, sp0, lights, rinf->num_lights);
nuclear@5 61 } else {
nuclear@5 62 fb[idx] = (float4)(0, 0, 0, 0);
nuclear@5 63 }
nuclear@4 64 }
nuclear@4 65
nuclear@5 66 float4 shade(struct Ray ray, struct SurfPoint sp,
nuclear@5 67 global const struct Light *lights, int num_lights)
nuclear@4 68 {
nuclear@8 69 float4 dcol = (float4)(0, 0, 0, 0);
nuclear@8 70 float4 scol = (float4)(0, 0, 0, 0);
nuclear@5 71
nuclear@5 72 for(int i=0; i<num_lights; i++) {
nuclear@8 73 float4 ldir = normalize(lights[i].pos - sp.pos);
nuclear@8 74 float4 vdir = -normalize(ray.dir);
nuclear@8 75 float4 vref = reflect(vdir, sp.norm);
nuclear@5 76
nuclear@5 77 float diff = fmax(dot(ldir, sp.norm), 0.0f);
nuclear@5 78 float spec = powr(fmax(dot(ldir, vref), 0.0f), sp.obj->spow);
nuclear@5 79
nuclear@8 80 dcol += sp.obj->kd * diff * lights[i].color;
nuclear@8 81 scol += sp.obj->ks * spec * lights[i].color;
nuclear@5 82 }
nuclear@5 83
nuclear@8 84 return dcol + scol;
nuclear@2 85 }
nuclear@2 86
nuclear@2 87 bool intersect(struct Ray ray,
nuclear@4 88 global const struct Sphere *sph,
nuclear@2 89 struct SurfPoint *sp)
nuclear@2 90 {
nuclear@8 91 float4 dir = ray.dir;
nuclear@8 92 float4 orig = ray.origin;
nuclear@8 93 float4 spos = sph->pos;
nuclear@2 94
nuclear@2 95 float a = dot(dir, dir);
nuclear@2 96 float b = 2.0 * dir.x * (orig.x - spos.x) +
nuclear@2 97 2.0 * dir.y * (orig.y - spos.y) +
nuclear@2 98 2.0 * dir.z * (orig.z - spos.z);
nuclear@2 99 float c = dot(spos, spos) + dot(orig, orig) +
nuclear@2 100 2.0 * dot(-spos, orig) - sph->radius * sph->radius;
nuclear@2 101
nuclear@2 102 float d = b * b - 4.0 * a * c;
nuclear@2 103 if(d < 0.0) return false;
nuclear@2 104
nuclear@2 105 float sqrt_d = sqrt(d);
nuclear@2 106 float t1 = (-b + sqrt_d) / (2.0 * a);
nuclear@2 107 float t2 = (-b - sqrt_d) / (2.0 * a);
nuclear@2 108
nuclear@2 109 if(t1 < EPSILON) t1 = t2;
nuclear@2 110 if(t2 < EPSILON) t2 = t1;
nuclear@2 111 float t = t1 < t2 ? t1 : t2;
nuclear@2 112
nuclear@2 113 if(t < EPSILON || t > 1.0) {
nuclear@2 114 return false;
nuclear@2 115 }
nuclear@2 116
nuclear@2 117 sp->t = t;
nuclear@2 118 sp->pos = orig + dir * sp->t;
nuclear@2 119 sp->norm = (sp->pos - spos) / sph->radius;
nuclear@5 120 sp->obj = sph;
nuclear@2 121 return true;
nuclear@2 122 }
nuclear@5 123
nuclear@8 124 float4 reflect(float4 v, float4 n)
nuclear@5 125 {
nuclear@5 126 return 2.0f * dot(v, n) * n - v;
nuclear@5 127 }
nuclear@8 128
nuclear@8 129 float4 transform(float4 v, global const float *xform)
nuclear@8 130 {
nuclear@8 131 float4 res;
nuclear@8 132 res.x = v.x * xform[0] + v.y * xform[4] + v.z * xform[8] + xform[12];
nuclear@8 133 res.y = v.x * xform[1] + v.y * xform[5] + v.z * xform[9] + xform[13];
nuclear@8 134 res.z = v.x * xform[2] + v.y * xform[6] + v.z * xform[10] + xform[14];
nuclear@8 135 res.w = 1.0;
nuclear@8 136 return res;
nuclear@8 137 }
nuclear@8 138
nuclear@8 139 struct Ray transform_ray(global const struct Ray *ray, global const float *xform)
nuclear@8 140 {
nuclear@8 141 struct Ray res;
nuclear@8 142 float rot[16];
nuclear@8 143
nuclear@8 144 for(int i=0; i<16; i++) {
nuclear@8 145 rot[i] = xform[i];
nuclear@8 146 }
nuclear@8 147 rot[3] = rot[7] = rot[11] = rot[12] = rot[13] = rot[14] = 0.0f;
nuclear@8 148 rot[15] = 1.0f;
nuclear@8 149
nuclear@8 150 res.origin = transform(ray->origin, xform);
nuclear@8 151 res.dir = transform(ray->dir, xform);
nuclear@8 152 return res;
nuclear@8 153 }