gpuray_glsl: 2ed3da7dc0bc src/rend.cc

gpuray_glsl

view src/rend.cc @ 4:2ed3da7dc0bc

broken

author	John Tsiombikas <nuclear@member.fsf.org>
date	Mon, 10 Nov 2014 01:26:00 +0200
parents	f234630e38ff
children

line source

1 #include <stdio.h>

2 #include <assert.h>

3 #include <algorithm>

4 #include "scene.h"

5 #include "image.h"

6 #include "rend.h"

7 #include "opengl.h"

8 #include "glsdr.h"

10 enum {

11 TEX_RAYDIR,

12 TEX_SPHERES,

13 TEX_PLANES,

14 TEX_BOXES,

15 TEX_CONES,

16 TEX_TEXTURES,

17 TEX_ENV,

18 TEX_XFORM,

20 NUM_SDR_TEXTURES

21 };

23 bool reload_shader();

24 void gen_ray_texture(unsigned int tex, int xsz, int ysz, float vfov);

25 static Vector3 get_primary_ray_dir(int x, int y, int w, int h, float vfov_deg);

26 static int round_pow2(int x);

28 static GPUScene *scn;

30 static unsigned int sdr;

31 static unsigned int textures[NUM_SDR_TEXTURES];

33 bool init_renderer(GPUScene *s, int xsz, int ysz)

34 {

35 scn = s;

37 int max_tex_units;

38 glGetIntegerv(GL_MAX_TEXTURE_IMAGE_UNITS, &max_tex_units);

39 printf("maximum texture units: %d\n", max_tex_units);

40 if(NUM_SDR_TEXTURES > max_tex_units) {

41 fprintf(stderr, "not enough texture units available!\n");

42 return false;

43 }

45 glGenTextures(1, textures + TEX_RAYDIR);

46 glBindTexture(GL_TEXTURE_2D, textures[TEX_RAYDIR]);

47 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

48 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

49 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);

50 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

52 if(!(s->create_textures())) {

53 fprintf(stderr, "failed to create scene textures\n");

54 return false;

55 }

57 textures[TEX_SPHERES] = s->get_texture(GPUScene::TEX_SPHERE);

58 textures[TEX_PLANES] = s->get_texture(GPUScene::TEX_PLANE);

59 textures[TEX_BOXES] = s->get_texture(GPUScene::TEX_BOX);

60 textures[TEX_CONES] = s->get_texture(GPUScene::TEX_CONE);

61 textures[TEX_TEXTURES] = s->get_texture(GPUScene::TEX_TEXTURE);

62 textures[TEX_ENV] = s->get_texture(GPUScene::TEX_ENV);

63 textures[TEX_XFORM] = s->get_texture(GPUScene::TEX_XFORM);

65 if(!reload_shader()) {

66 return false;

67 }

69 resize_renderer(xsz, ysz);

71 return true;

72 }

74 bool reload_shader()

75 {

76 if(sdr) {

77 free_program(sdr);

78 }

80 printf("loading shader...\n");

82 if(!(sdr = create_program_load("sdr/vertex.glsl", "sdr/rt.glsl"))) {

83 return false;

84 }

85 set_uniform_int(sdr, "tex_raydir", TEX_RAYDIR);

86 set_uniform_int(sdr, "tex_spheres", TEX_SPHERES);

87 set_uniform_int(sdr, "tex_planes", TEX_PLANES);

88 set_uniform_int(sdr, "tex_boxes", TEX_BOXES);

89 set_uniform_int(sdr, "tex_cones", TEX_CONES);

90 set_uniform_int(sdr, "tex_megatex", TEX_TEXTURES);

91 set_uniform_int(sdr, "tex_env", TEX_ENV);

92 set_uniform_int(sdr, "tex_xforms", TEX_XFORM);

94 set_uniform_int(sdr, "num_lights", scn->get_light_count());

96 for(int i=0; i<scn->get_light_count(); i++) {

97 const Light *lt = scn->get_light(i);

99 char name[64];

100 sprintf(name, "lights[%d].pos", i);

101 set_uniform_float3(sdr, name, lt->pos.x, lt->pos.y, lt->pos.z);

102

103 sprintf(name, "lights[%d].color", i);

104 set_uniform_float3(sdr, name, lt->color.x, lt->color.y, lt->color.z);

105 }

106

107 Vector2 fog;

108 scn->get_fog(&fog.x, &fog.y);

109 if(fog.x < 0.0 && fog.y < 0.0) {

110 fog.x = 0.0;

111 fog.y = 100000.0;

112 }

113 set_uniform_float2(sdr, "fog", fog.x, fog.y);

114 return true;

115 }

116

117 void destroy_renderer()

118 {

119 free_program(sdr);

120 sdr = 0;

121 }

122

123 void resize_renderer(int xsz, int ysz)

124 {

125 gen_ray_texture(textures[TEX_RAYDIR], xsz, ysz, 45.0f);

126 }

127

128 float *render_frame(long msec)

129 {

130 scn->prepare_xform(msec);

131 scn->update_xform_texture();

132

133 Camera *cam = scn->get_camera();

134 glMatrixMode(GL_MODELVIEW);

135 glLoadIdentity();

136 Vector3 cpos = cam->get_position();

137 glTranslatef(cpos.x, cpos.y, cpos.z);

138 Matrix4x4 cmat = cam->get_matrix();

139 glMultTransposeMatrixf(cmat[0]);

140

141 for(int i=0; i<NUM_SDR_TEXTURES; i++) {

142 glActiveTexture(GL_TEXTURE0 + i);

143 if(i == TEX_ENV) {

144 glBindTexture(GL_TEXTURE_CUBE_MAP, textures[i]);

145 } else {

146 glBindTexture(GL_TEXTURE_2D, textures[i]);

147 }

148 }

149 glActiveTexture(GL_TEXTURE0);

150

151 glUseProgram(sdr);

152

153 glBegin(GL_QUADS);

154 glTexCoord2f(0, 1);

155 glVertex2f(-1, -1);

156 glTexCoord2f(1, 1);

157 glVertex2f(1, -1);

158 glTexCoord2f(1, 0);

159 glVertex2f(1, 1);

160 glTexCoord2f(0, 0);

161 glVertex2f(-1, 1);

162 glEnd();

163

164 glUseProgram(0);

165

166 assert(glGetError() == GL_NO_ERROR);

167 return 0;

168 }

169

170 void gen_ray_texture(unsigned int tex, int xsz, int ysz, float vfov)

171 {

172 int tex_xsz = round_pow2(xsz);

173 int tex_ysz = round_pow2(ysz);

174 float *teximg, *dir;

175

176 teximg = new float[3 * tex_xsz * tex_ysz];

177 dir = teximg;

178

179 for(int i=0; i<tex_ysz; i++) {

180 for(int j=0; j<tex_xsz; j++) {

181 if(j < xsz && i < ysz) {

182 Vector3 rdir = get_primary_ray_dir(j, i, xsz, ysz, vfov);

183 dir[0] = rdir.x;

184 dir[1] = rdir.y;

185 dir[2] = rdir.z;

186 } else {

187 dir[0] = dir[1] = 0.0f;

188 dir[2] = 1.0f;

189 }

190

191 dir += 3;

192 }

193 }

194

195 glBindTexture(GL_TEXTURE_2D, tex);

196 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB16F, tex_xsz, tex_ysz, 0, GL_RGB, GL_FLOAT, teximg);

197 delete [] teximg;

198 }

199

200 static Vector3 calc_sample_pos(int x, int y, int xsz, int ysz)

201 {

202 float ppos[2];

203 float aspect = (float)xsz / (float)ysz;

204

205 float pwidth = 2.0 * aspect / (float)xsz;

206 float pheight = 2.0 / (float)ysz;

207

208 ppos[0] = (float)x * pwidth - aspect;

209 ppos[1] = 1.0 - (float)y * pheight;

210

211 return Vector3(ppos[0], ppos[1], 0.0f);

212 }

213

214

215 static Vector3 get_primary_ray_dir(int x, int y, int w, int h, float vfov_deg)

216 {

217 float vfov = M_PI * vfov_deg / 180.0;

218

219 Vector3 dir = calc_sample_pos(x, y, w, h);

220 dir.z = 1.0 / tan(vfov / 2.0);

221 dir.normalize();

222

223 return dir;

224 }

225

226 static int round_pow2(int x)

227 {

228 x--;

229 x = (x >> 1) | x;

230 x = (x >> 2) | x;

231 x = (x >> 4) | x;

232 x = (x >> 8) | x;

233 x = (x >> 16) | x;

234 return x + 1;

235 }

236

237

238 #if 0

239 Color trace_ray(const Scene *scn, const Ray &ray, int rdepth)

240 {

241 HitPoint hit;

242

243 if(scn->intersect(ray, &hit)) {

244 float t;

245 if(scn->fog_start >= 0.0 && (t = (hit.dist - scn->fog_start) / (scn->fog_end - scn->fog_start)) > 0.0) {

246 return lerp(shade(scn, ray, hit, rdepth), scn->env_color(ray), t > 1.0 ? 1.0 : t);

247 }

248 return shade(scn, ray, hit, rdepth);

249 }

250

251 return scn->env_color(ray);

252 }

253

254 Color shade(const Scene *scn, const Ray &ray, const HitPoint &hit, int rdepth)

255 {

256 const Material *mat = &hit.obj->material;

257

258 // if we're leaving the object, we need to invert the normal (and ior)

259 Vector3 normal;

260 bool entering;

261 if(dot_product(hit.normal, ray.dir) <= 0.0) {

262 normal = hit.normal;

263 entering = true;

264 } else {

265 normal = -hit.normal;

266 entering = false;

267 }

268

269 Vector3 vdir = -ray.dir;

270

271 Color diffuse_color = mat->diffuse;

272 Color tex_color{1, 1, 1};

273 if(mat->tex) {

274 tex_color *= mat->tex->sample(hit);

275 diffuse_color *= tex_color;

276 }

277

278 Color color = mat->emission * tex_color;

279

280 // image-based lighting

281 if(scn->envmap_conv) {

282 // pick a random direction and create a sampling ray

283 Ray envray;

284 envray.origin = hit.pos;

285 rand_dir(&envray.dir.x, &envray.dir.y, &envray.dir.z, (unsigned int*)ray.user);

286 if(dot_product(envray.dir, normal) < 0.0) {

287 envray.dir = -envray.dir;

288 }

289

290 HitPoint env_hit;

291 if(!scn->intersect(envray, &env_hit)) {

292 Vector3 dir = envray.dir;

293 color += scn->envmap_conv->sample(dir.x, dir.y, dir.z) * diffuse_color;

294 }

295 }

296

297 for(Light *lt: scn->lights) {

298

299 /* construct a shadow ray to determine if there is an uninterrupted

300 * path between the intersection point and the light source

301 */

302 Ray shadow_ray = ray;

303 shadow_ray.origin = hit.pos;

304 shadow_ray.dir = lt->pos - hit.pos;

305

306 /* the interval [0, 1] represents the part of the ray from the origin

307 * to the light. We don't care about intersections behind the origin

308 * of the shadow ray (behind the surface of the object), or after the

309 * light source. We only care if there's something in between hiding the

310 * light.

311 */

312 HitPoint shadow_hit;

313 if(scn->intersect(shadow_ray, &shadow_hit) && shadow_hit.dist < 1.0f) {

314 continue; // skip this light, it's hidden from view

315 }

316

317 // calculate the light direction

318 Vector3 ldir = shadow_ray.dir.normalized();

319 // calculate the reflected light direction

320 Vector3 lref = ldir.reflection(normal);

321

322 float diffuse = std::max(dot_product(ldir, normal), 0.0f);

323 float specular = pow(std::max(dot_product(lref, vdir), 0.0f), mat->shininess);

324

325 color += (diffuse_color * diffuse + mat->specular * specular) * lt->color;

326 }

327

328 Color spec_col;

329

330 if(mat->reflectivity > 0.001f && rdepth < MAX_RAY_DEPTH) {

331 Ray refl_ray{ray};

332 refl_ray.origin = hit.pos;

333 refl_ray.dir = -ray.dir.reflection(normal);

334

335 spec_col += trace_ray(scn, refl_ray, rdepth + 1) * mat->reflectivity;

336 }

337

338 if(mat->transparency > 0.001f && rdepth < MAX_RAY_DEPTH) {

339 float from_ior = entering ? 1.0 : mat->ior;

340 float to_ior = entering ? mat->ior : 1.0;

341

342 Ray refr_ray{ray};

343 refr_ray.origin = hit.pos;

344 refr_ray.dir = ray.dir.refraction(normal, from_ior / to_ior);

345

346 Color tcol = trace_ray(scn, refr_ray, rdepth + 1) * mat->transparency;

347

348 float fres = fresnel(ray.dir, refr_ray.dir, normal, from_ior, to_ior);

349 spec_col = spec_col * fres + tcol * (1.0 - fres);

350 }

351

352 return color + spec_col;

353 }

354

355

356 static void rand_dir(float *x, float *y, float *z, unsigned int *seedp)

357 {

358 float u = (float)rand_r(seedp) / RAND_MAX;

359 float v = (float)rand_r(seedp) / RAND_MAX;

360

361 float theta = 2.0 * M_PI * u;

362 float phi = acos(2.0 * v - 1.0);

363

364 *x = cos(theta) * sin(phi);

365 *y = sin(theta) * sin(phi);

366 *z = cos(phi);

367 }

368

369 static float fresnel(const Vector3 &inc, const Vector3 &trans, const Vector3 &norm, float ior_inc, float ior_trans)

370 {

371 float cos_inc = dot_product(-inc, norm);

372 float cos_trans = dot_product(-trans, norm);

373

374 return fresnel(cos_inc, cos_trans, ior_inc, ior_trans);

375 }

376

377 static float fresnel(float cos_inc, float cos_trans, float ior_inc, float ior_trans)

378 {

379 float r0 = ((ior_trans * cos_inc) - (ior_inc * cos_trans)) /

380 ((ior_trans * cos_inc) + (ior_inc * cos_trans));

381 float r1 = ((ior_inc * cos_inc) - (ior_trans * cos_trans)) /

382 ((ior_inc * cos_inc) + (ior_trans * cos_trans));

383 return (r0 * r0 + r1 * r1) * 0.5f;

384 }

385 #endif