gpuray_glsl: 297dbc5080c4 sdr/rt.glsl

gpuray_glsl

view sdr/rt.glsl @ 3:297dbc5080c4

cone intersection

author	John Tsiombikas <nuclear@member.fsf.org>
date	Sun, 09 Nov 2014 20:13:33 +0200
parents
children	2ed3da7dc0bc

line source

1 /* vi:set filetype=glsl ts=4 sw=4: */

2 #version 120

3 #extension GL_ARB_gpu_shader5 : enable

5 #define M_PI 3.1415926

7 #define INIT_EVERYTHING

8 #define USE_XFORM

9 #define OBJ_LINE_WIDTH 16.0

11 struct Ray {

12 vec3 origin, dir;

13 };

15 struct Material {

16 vec3 diffuse, specular;

17 float shininess;

18 vec4 megatex_rect;

19 float reflectivity;

20 };

22 struct HitPoint {

23 float dist;

24 vec3 pos, normal;

25 vec2 texcoord;

26 struct Material mat;

27 };

29 struct Sphere {

30 float index;

31 vec3 pos;

32 float radius;

33 struct Material mat;

34 };

36 struct Plane {

37 float index;

38 vec3 normal;

39 float dist;

40 struct Material mat;

41 };

43 struct Box {

44 float index;

45 vec3 min, max;

46 struct Material mat;

47 };

49 struct Light {

50 vec3 pos, color;

51 };

53 vec3 shade(in Ray ray, in HitPoint hit);

54 bool find_intersection(in Ray ray, out HitPoint hit);

55 bool sphere_intersect(in Sphere sph, in Ray ray, out HitPoint pt);

56 bool plane_intersect(in Plane plane, in Ray ray, out HitPoint pt);

57 bool box_intersect(in Box box, in Ray ray, out HitPoint pt);

58 vec3 transform(in vec3 v, in mat4 inv_xform);

59 Ray transform(in Ray ray, in mat4 xform, in mat4 inv_xform);

60 Ray get_primary_ray();

62 Sphere read_sphere(in float idx);

63 Plane read_plane(in float idx);

64 Box read_box(in float idx);

65 Material read_material(in sampler2D tex, in float ty);

66 void read_xform(in float idx, out mat4 xform, out mat4 inv_xform);

68 uniform sampler2D tex_raydir;

69 uniform sampler2D tex_spheres, tex_planes, tex_boxes;

70 uniform sampler2D tex_megatex;

71 uniform sampler2D tex_xforms;

72 uniform samplerCube tex_env;

73 uniform vec2 fog;

75 uniform Light lights[8];

76 uniform int num_lights;

78 int num_spheres, num_planes, num_boxes;

79 float sph_tex_sz, plane_tex_sz, box_tex_sz, xform_tex_sz;

81 #ifdef INIT_EVERYTHING

82 Material default_material;

83 #endif

85 void main()

86 {

87 #ifdef INIT_EVERYTHING

88 default_material.diffuse = default_material.specular = vec3(0.0, 0.0, 0.0);

89 default_material.shininess = 1.0;

90 default_material.reflectivity = 0.0;

91 default_material.megatex_rect = vec4(0.0, 0.0, 0.0, 0.0);

92 #endif

94 Ray ray = get_primary_ray();

96 /* read the various descriptors specifying dimensions and counts for

97 * all the relevant data textures

98 */

99 vec4 desc = texture2D(tex_spheres, vec2(0.0, 0.0));

100 num_spheres = int(desc.x);

101 sph_tex_sz = desc.y;

102

103 desc = texture2D(tex_planes, vec2(0.0, 0.0));

104 num_planes = int(desc.x);

105 plane_tex_sz = desc.y;

106

107 desc = texture2D(tex_boxes, vec2(0.0, 0.0));

108 num_boxes = int(desc.x);

109 box_tex_sz = desc.y;

110

111 xform_tex_sz = texture2D(tex_xforms, vec2(0.0, 0.0)).x;

112

113

114 HitPoint hit;

115 #ifdef INIT_EVERYTHING

116 hit.dist = 0.0;

117 hit.pos = hit.normal = vec3(0.0, 0.0, 0.0);

118 #endif

119

120 vec3 color = vec3(0.0, 0.0, 0.0);

121 float energy = 1.0;

122

123 int iter = 0;

124 while(energy > 0.01 && iter++ < 4) {

125 vec3 envcol = textureCube(tex_env, ray.dir).xyz;

126

127 if(find_intersection(ray, hit)) {

128 float fog_t = clamp((hit.dist - fog.x) / (fog.y - fog.x), 0.0, 1.0);

129 color += mix(shade(ray, hit), envcol, fog_t) * energy;

130 energy *= hit.mat.reflectivity * (1.0 - fog_t);

131 ray.origin = hit.pos;

132 ray.dir = reflect(ray.dir, hit.normal);

133 } else {

134 color += envcol * energy;

135 energy = 0.0;

136 iter = 100;

137 }

138 }

139

140 gl_FragColor.xyz = color;

141 gl_FragColor.w = 1.0;

142 }

143

144 vec3 shade(in Ray ray, in HitPoint hit)

145 {

146 vec3 normal = faceforward(hit.normal, ray.dir, hit.normal);

147

148 vec3 vdir = normalize(ray.dir);

149 vec3 vref = reflect(vdir, normal);

150

151 /* if there's no texture rect.zw will be (0, 0, 0, 0) so this will map onto

152 * the top-left 1x1 null texture which is all white (having no effect)

153 */

154 vec2 tc = mod(hit.texcoord, vec2(1.0, 1.0)) * hit.mat.megatex_rect.zw + hit.mat.megatex_rect.xy;

155

156 vec3 diffuse_color = hit.mat.diffuse * texture2D(tex_megatex, tc).xyz;

157

158 vec3 color = vec3(0.0, 0.0, 0.0);

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

160 Ray shadow_ray;

161 shadow_ray.origin = hit.pos;

162 shadow_ray.dir = lights[i].pos - hit.pos;

163

164 HitPoint shadow_hit;

165 if(!find_intersection(shadow_ray, shadow_hit) || shadow_hit.dist > 1.0) {

166 vec3 ldir = normalize(shadow_ray.dir);

167

168 float diffuse = max(dot(ldir, normal), 0.0);

169 float specular = pow(max(dot(ldir, vref), 0.0), hit.mat.shininess);

170

171 color += (diffuse_color * diffuse + hit.mat.specular * specular) * lights[i].color;

172 }

173 }

174

175 return color;

176 }

177

178 bool find_intersection(in Ray ray, out HitPoint hit)

179 {

180 hit.dist = 100000.0;

181 #ifdef INIT_EVERYTHING

182 hit.pos = hit.normal = vec3(0.0, 0.0, 0.0);

183 hit.mat = default_material;

184 hit.texcoord = vec2(0.0, 0.0);

185 #endif

186 bool found = false;

187

188 for(int i=0; i<num_spheres; i++) {

189 Sphere sph = read_sphere(i);

190

191 HitPoint tmphit;

192 if(sphere_intersect(sph, ray, tmphit) && tmphit.dist < hit.dist) {

193 hit = tmphit;

194 found = true;

195 }

196 }

197

198 for(int i=0; i<num_planes; i++) {

199 Plane plane = read_plane(i);

200

201 HitPoint tmphit;

202 if(plane_intersect(plane, ray, tmphit) && tmphit.dist < hit.dist) {

203 hit = tmphit;

204 found = true;

205 }

206 }

207

208 for(int i=0; i<num_boxes; i++) {

209 Box box = read_box(i);

210

211 HitPoint tmphit;

212 if(box_intersect(box, ray, tmphit) && tmphit.dist < hit.dist) {

213 hit = tmphit;

214 found = true;

215 }

216 }

217

218 return found;

219 }

220

221 #define EPSILON 1e-4

222 #define SQ(x) ((x) * (x))

223

224 bool sphere_intersect(in Sphere sph, in Ray inray, out HitPoint pt)

225 {

226 #ifdef USE_XFORM

227 mat4 xform, inv_xform;

228 read_xform(sph.index, xform, inv_xform);

229

230 Ray ray = transform(inray, inv_xform, xform);

231 #else

232 Ray ray = inray;

233 #endif

234

235 #ifdef INIT_EVERYTHING

236 pt.dist = 0.0;

237 pt.pos = pt.normal = vec3(0.0, 0.0, 0.0);

238 pt.mat = default_material;

239 pt.texcoord = vec2(0.0, 0.0);

240 #endif

241

242 float a = dot(ray.dir, ray.dir);

243 float b = dot(ray.dir, ray.origin - sph.pos) * 2.0;

244 float c = dot(ray.origin, ray.origin) + dot(sph.pos, sph.pos) -

245 2.0 * dot(ray.origin, sph.pos) - sph.radius * sph.radius;

246

247 float discr = b * b - 4.0 * a * c;

248 if(discr < EPSILON)

249 return false;

250

251 float sqrt_discr = sqrt(discr);

252 float t0 = (-b + sqrt_discr) / (2.0 * a);

253 float t1 = (-b - sqrt_discr) / (2.0 * a);

254

255 if(t0 < EPSILON)

256 t0 = t1;

257 if(t1 < EPSILON)

258 t1 = t0;

259

260 float t = min(t0, t1);

261 if(t < EPSILON)

262 return false;

263

264 // fill the HitPoint structure

265 pt.dist = t;

266 pt.pos = ray.origin + ray.dir * t;

267 pt.normal = (pt.pos - sph.pos) / sph.radius;

268 pt.mat = sph.mat;

269

270 pt.texcoord.x = 0.5 * atan(pt.normal.z, pt.normal.x) / M_PI + 0.5;

271 pt.texcoord.y = acos(pt.normal.y) / M_PI;

272

273 #ifdef USE_XFORM

274 pt.pos = (xform * vec4(pt.pos, 1.0)).xyz;

275 pt.normal = normalize(transform(pt.normal, xform));

276 #endif

277 return true;

278 }

279

280 bool plane_intersect(in Plane plane, in Ray inray, out HitPoint pt)

281 {

282 #ifdef USE_XFORM

283 mat4 xform, inv_xform;

284 read_xform(plane.index, xform, inv_xform);

285

286 Ray ray = transform(inray, inv_xform, xform);

287 #else

288 Ray ray = inray;

289 #endif

290

291 #ifdef INIT_EVERYTHING

292 pt.dist = 0.0;

293 pt.pos = pt.normal = vec3(0.0, 0.0, 0.0);

294 pt.mat = default_material;

295 pt.texcoord = vec2(0.0, 0.0);

296 #endif

297

298 float ndotdir = dot(plane.normal, ray.dir);

299 if(abs(ndotdir) < EPSILON) {

300 return false;

301 }

302

303 vec3 planept = plane.normal * plane.dist;

304 vec3 pptdir = planept - ray.origin;

305

306 float t = dot(plane.normal, pptdir) / ndotdir;

307 if(t < EPSILON) {

308 return false;

309 }

310

311 pt.dist = t;

312 pt.pos = ray.origin + ray.dir * t;

313 pt.normal = plane.normal;

314 pt.mat = plane.mat;

315 pt.texcoord.x = pt.pos.x;

316 pt.texcoord.y = pt.pos.z;

317

318 #ifdef USE_XFORM

319 pt.pos = (xform * vec4(pt.pos, 1.0)).xyz;

320 pt.normal = normalize(transform(pt.normal, xform));

321 #endif

322 return true;

323 }

324

325 bool box_intersect(in Box box, in Ray inray, out HitPoint pt)

326 {

327 #ifdef USE_XFORM

328 mat4 xform, inv_xform;

329 read_xform(box.index, xform, inv_xform);

330

331 Ray ray = transform(inray, inv_xform, xform);

332 #else

333 Ray ray = inray;

334 #endif

335

336 #ifdef INIT_EVERYTHING

337 pt.dist = 0.0;

338 pt.pos = pt.normal = vec3(0.0, 0.0, 0.0);

339 pt.mat = default_material;

340 pt.texcoord = vec2(0.0, 0.0);

341 #endif

342

343 vec3 param[2];

344 param[0] = box.min;

345 param[1] = box.max;

346

347 vec3 inv_dir = 1.0 / ray.dir;

348 int sgn[3];

349 sgn[0] = inv_dir.x < 0.0 ? 1 : 0;

350 sgn[1] = inv_dir.y < 0.0 ? 1 : 0;

351 sgn[2] = inv_dir.z < 0.0 ? 1 : 0;

352

353 float tmin = (param[sgn[0]].x - ray.origin.x) * inv_dir.x;

354 float tmax = (param[1 - sgn[0]].x - ray.origin.x) * inv_dir.x;

355 float tymin = (param[sgn[1]].y - ray.origin.y) * inv_dir.y;

356 float tymax = (param[1 - sgn[1]].y - ray.origin.y) * inv_dir.y;

357

358 pt.normal = vec3(ray.origin.x > 0.0 ? 1.0 : -1.0, 0.0, 0.0);

359

360 if(tmin > tymax || tymin > tmax) {

361 return false;

362 }

363 if(tymin > tmin) {

364 pt.normal = vec3(0.0, ray.origin.y > 0.0 ? 1.0 : -1.0, 0.0);

365 tmin = tymin;

366 }

367 if(tymax < tmax) {

368 tmax = tymax;

369 }

370

371 float tzmin = (param[sgn[2]].z - ray.origin.z) * inv_dir.z;

372 float tzmax = (param[1 - sgn[2]].z - ray.origin.z) * inv_dir.z;

373

374 if(tmin > tzmax || tzmin > tmax) {

375 return false;

376 }

377 if(tzmin > tmin) {

378 pt.normal = vec3(0.0, 0.0, ray.origin.z > 0.0 ? 1.0 : -1.0);

379 tmin = tzmin;

380 }

381 if(tzmax < tmax) {

382 tmax = tzmax;

383 }

384

385 float t = tmin < EPSILON ? tmax : tmin;

386 if(t >= 1e-4) {

387 pt.dist = t;

388 pt.pos = ray.origin + ray.dir * t;

389 pt.mat = box.mat;

390

391 float min_dist = 10000.0;

392

393 vec3 offs = box.min + (box.max - box.min) / 2.0;

394 vec3 local_pt = pt.pos - offs;

395

396 vec3 dist = abs((box.max - offs) - abs(local_pt));

397 if(dist.x < min_dist) {

398 min_dist = dist.x;

399 pt.normal = sign(local_pt.x) * vec3(1.0, 0.0, 0.0);

400 pt.texcoord = pt.pos.zy;

401 }

402 if(dist.y < min_dist) {

403 min_dist = dist.y;

404 pt.normal = sign(local_pt.y) * vec3(0.0, 1.0, 0.0);

405 pt.texcoord = pt.pos.xz;

406 }

407 if(dist.z < min_dist) {

408 pt.normal = sign(local_pt.y) * vec3(0.0, 0.0, 1.0);

409 pt.texcoord = pt.pos.xy;

410 }

411

412

413 #ifdef USE_XFORM

414 pt.pos = (xform * vec4(pt.pos, 1.0)).xyz;

415 pt.normal = normalize(transform(pt.normal, xform));

416 #endif

417 return true;

418 }

419 return false;

420 }

421

422 vec3 transform(in vec3 v, in mat4 xform)

423 {

424 return mat3(xform) * v;

425 }

426

427 Ray transform(in Ray ray, in mat4 xform, in mat4 inv_xform)

428 {

429 Ray res;

430 res.origin = (xform * vec4(ray.origin, 1.0)).xyz;

431 res.dir = transform(ray.dir, xform);

432 return res;

433 }

434

435 Ray get_primary_ray()

436 {

437 Ray ray;

438 ray.origin = (gl_ModelViewMatrix * vec4(0.0, 0.0, 0.0, 1.0)).xyz;

439 vec3 dir = texture2D(tex_raydir, gl_TexCoord[0].st).xyz;

440 ray.dir = normalize(gl_NormalMatrix * dir);

441 return ray;

442 }

443

444 #define ITEM(x) ((float(x) + 0.5) / OBJ_LINE_WIDTH)

445

446 Sphere read_sphere(in float idx)

447 {

448 Sphere sph;

449 // +1 because the first scanline is the descriptor

450 float ty = (idx + 1.0) / sph_tex_sz;

451

452 sph.index = texture2D(tex_spheres, vec2(ITEM(0), ty)).x;

453

454 vec4 texel = texture2D(tex_spheres, vec2(ITEM(1), ty));

455 sph.pos = texel.xyz;

456 sph.radius = texel.w;

457

458 sph.mat = read_material(tex_spheres, ty);

459 return sph;

460 }

461

462 Plane read_plane(in float idx)

463 {

464 Plane plane;

465 // +1 (see above)

466 float ty = (idx + 1.0) / plane_tex_sz;

467

468 plane.index = texture2D(tex_planes, vec2(ITEM(0), ty)).x;

469

470 vec4 texel = texture2D(tex_planes, vec2(ITEM(1), ty));

471 plane.normal = texel.xyz;

472 plane.dist = texel.w;

473

474 plane.mat = read_material(tex_planes, ty);

475 return plane;

476 }

477

478 Box read_box(in float idx)

479 {

480 Box box;

481 float ty = (idx + 1.0) / box_tex_sz;

482

483 box.index = texture2D(tex_boxes, vec2(ITEM(0), ty)).x;

484

485 box.min = texture2D(tex_boxes, vec2(ITEM(1), ty)).xyz;

486 box.max = texture2D(tex_boxes, vec2(ITEM(2), ty)).xyz;

487

488 box.mat = read_material(tex_boxes, ty);

489 return box;

490 }

491

492 void read_xform(in float idx, out mat4 xform, out mat4 inv_xform)

493 {

494 float ty = (idx + 1.0) / xform_tex_sz;

495

496 for(int i=0; i<4; i++) {

497 xform[i] = texture2D(tex_xforms, vec2(ITEM(i), ty));

498 }

499 inv_xform = inverse(xform);

500 /*for(int i=0; i<4; i++) {

501 inv_xform[i] = texture2D(tex_xforms, vec2(ITEM(float(i) + 4.0), ty));

502 }*/

503 }

504

505 #define MAT_START 4

506 Material read_material(in sampler2D tex, in float ty)

507 {

508 Material mat;

509

510 vec4 texel = texture2D(tex, vec2(ITEM(MAT_START), ty));

511 mat.diffuse = texel.xyz;

512

513 texel = texture2D(tex, vec2(ITEM(MAT_START + 1), ty));

514 mat.specular = texel.xyz;

515 mat.shininess = texel.w;

516

517 texel = texture2D(tex, vec2(ITEM(MAT_START + 2), ty));

518 mat.reflectivity = texel.x;

519

520 mat.megatex_rect = texture2D(tex, vec2(ITEM(MAT_START + 3), ty));

521

522 return mat;

523 }