qvolray: 3d05c261a2f4 src/volray.cc

qvolray

view src/volray.cc @ 18:3d05c261a2f4

demo metaballs crash & burn

author	John Tsiombikas <nuclear@member.fsf.org>
date	Wed, 11 Apr 2012 06:08:59 +0300
parents	17d9dc2edc91
children	784d3d321caa

line source

1 #include <stdio.h>

2 #include <stdlib.h>

3 #include <assert.h>

5 #include <GL/glew.h>

6 #ifndef __APPLE__

7 #include <GL/glut.h>

8 #else

9 #include <GLUT/glut.h>

10 #endif

12 #include <vmath/vmath.h>

13 #include <imago2.h>

14 #include "sdr.h"

15 #include "volume.h"

16 #include "ui.h"

17 #include "demo.h"

19 #define XFER_MAP_SZ 512

21 static void render_volume();

22 static void draw_slice();

23 static void draw_xfer_func();

25 /*

26 void keyb(unsigned char key, int x, int y);

27 void keyb_up(unsigned char key, int x, int y);

28 void mouse(int bn, int state, int x, int y);

29 void motion(int x, int y);

30 int parse_args(int argc, char **argv);

31 */

33 static void create_ray_texture(int xsz, int ysz, float vfov, Vector2 *tex_scale);

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

35 static int round_pow2(int x);

36 static void create_transfer_map(float mean, float sdev);

38 static float cam_theta = 0, cam_phi = 0, cam_dist = 4.0;

39 static float cam_x, cam_y, cam_z;

41 static Vector2 tex_scale;

42 static unsigned int vol_sdr, slice_sdr, ray_tex;

43 static int win_xsz, win_ysz;

44 static bool raytex_needs_recalc = true;

46 static unsigned int xfer_tex;

47 static float xfer_mean = 0.7, xfer_sdev = 0.1;

48 static bool xfertex_needs_recalc = true;

50 static float cur_z = 0.0;

51 static float ray_step = 0.01;

53 static Volume *volume;

56 bool volray_init()

57 {

58 glewInit();

60 if(!(vol_sdr = create_program_load("sdr/volray.v.glsl", "sdr/volray.p.glsl"))) {

61 return false;

62 }

63 set_uniform_int(vol_sdr, "volume", 0);

64 set_uniform_int(vol_sdr, "ray_tex", 1);

65 set_uniform_int(vol_sdr, "xfer_tex", 2);

66 set_uniform_float(vol_sdr, "ray_step", ray_step);

67 set_uniform_float(vol_sdr, "zclip", cur_z);

69 if(!(slice_sdr = create_program_load(0, "sdr/slice.p.glsl"))) {

70 return false;

71 }

72 set_uniform_int(slice_sdr, "volume", 0);

73 set_uniform_int(slice_sdr, "xfer_tex", 1);

75 init_demo();

77 return true;

78 }

80 void volray_setvolume(Volume *vol)

81 {

82 volume = vol;

83 }

85 Volume *volray_getvolume()

86 {

87 return volume;

88 }

90 void volray_draw(void)

91 {

92 /* recalculate primary ray texture if needed */

93 if(raytex_needs_recalc) {

94 create_ray_texture(win_xsz, win_ysz, 50.0, &tex_scale);

95 }

96 /* recalculate transfer function texture if needed */

97 if(xfertex_needs_recalc) {

98 create_transfer_map(xfer_mean, xfer_sdev);

99 }

100

101 draw_demo();

102

103 glClear(GL_COLOR_BUFFER_BIT);

104

105 if(volume) {

106 render_volume();

107 draw_slice();

108 draw_xfer_func();

109 }

110

111 assert(glGetError() == GL_NO_ERROR);

112 }

113

114 static void render_volume(void)

115 {

116 /* set the camera transformation */

117 glMatrixMode(GL_MODELVIEW);

118 glPushMatrix();

119 glLoadIdentity();

120 glRotatef(-90, 1, 0, 0);

121 glTranslatef(cam_x, cam_y, -cam_z);

122 glRotatef(cam_theta, 0, 1, 0);

123 glRotatef(cam_phi, 1, 0, 0);

124 glTranslatef(0, 0, -cam_dist);

125

126 /* setup the texture matrix to map the useful part of the ray texture to [0,1] */

127 glMatrixMode(GL_TEXTURE);

128 glPushMatrix();

129 glLoadIdentity();

130 glScalef(tex_scale.x, tex_scale.y, 1.0);

131

132 /* tex unit0: volume data 3D texture */

133 glActiveTexture(GL_TEXTURE0);

134 glBindTexture(GL_TEXTURE_3D, volume->get_texture());

135 glEnable(GL_TEXTURE_3D);

136

137 /* tex unit1: primary rays in view space */

138 glActiveTexture(GL_TEXTURE1);

139 glBindTexture(GL_TEXTURE_2D, ray_tex);

140 glEnable(GL_TEXTURE_2D);

141

142 /* tex unit2: transfer function (1d) */

143 glActiveTexture(GL_TEXTURE2);

144 glBindTexture(GL_TEXTURE_1D, xfer_tex);

145 glEnable(GL_TEXTURE_1D);

146

147 bind_program(vol_sdr);

148 glBegin(GL_QUADS);

149 glColor3f(1, 1, 1);

150 glTexCoord2f(0, 1); glVertex2f(-1, -1);

151 glTexCoord2f(1, 1); glVertex2f(1, -1);

152 glTexCoord2f(1, 0); glVertex2f(1, 1);

153 glTexCoord2f(0, 0); glVertex2f(-1, 1);

154 glEnd();

155 bind_program(0);

156

157 glActiveTexture(GL_TEXTURE2);

158 glDisable(GL_TEXTURE_1D);

159 glActiveTexture(GL_TEXTURE1);

160 glDisable(GL_TEXTURE_2D);

161 glActiveTexture(GL_TEXTURE0);

162 glDisable(GL_TEXTURE_3D);

163

164 glMatrixMode(GL_TEXTURE);

165 glPopMatrix();

166 glMatrixMode(GL_MODELVIEW);

167 glPopMatrix();

168 }

169

170 static void draw_slice(void)

171 {

172 glMatrixMode(GL_MODELVIEW);

173 glPushMatrix();

174 glTranslatef(0.9, 0.9, 0);

175 glScalef(0.3, 0.3 * ((float)win_xsz / win_ysz), 1);

176 glTranslatef(-1, -1, 0);

177

178 glActiveTexture(GL_TEXTURE0);

179 glBindTexture(GL_TEXTURE_3D, volume->get_texture());

180 glEnable(GL_TEXTURE_3D);

181

182 glActiveTexture(GL_TEXTURE1);

183 glBindTexture(GL_TEXTURE_1D, xfer_tex);

184 glEnable(GL_TEXTURE_1D);

185

186 bind_program(slice_sdr);

187

188 glBegin(GL_QUADS);

189 glColor3f(1, 1, 1);

190 glTexCoord3f(0, 1, cur_z); glVertex2f(-1, -1);

191 glTexCoord3f(1, 1, cur_z); glVertex2f(1, -1);

192 glTexCoord3f(1, 0, cur_z); glVertex2f(1, 1);

193 glTexCoord3f(0, 0, cur_z); glVertex2f(-1, 1);

194 glEnd();

195

196 bind_program(0);

197

198 glActiveTexture(GL_TEXTURE1);

199 glDisable(GL_TEXTURE_1D);

200 glActiveTexture(GL_TEXTURE0);

201 glDisable(GL_TEXTURE_3D);

202 glPopMatrix();

203 }

204

205 static void draw_xfer_func(void)

206 {

207 glMatrixMode(GL_MODELVIEW);

208 glPushMatrix();

209 glTranslatef(-0.9, -0.9, 0);

210 glScalef(0.5, 0.1, 1);

211

212 glBindTexture(GL_TEXTURE_1D, xfer_tex);

213 glEnable(GL_TEXTURE_1D);

214

215 glBegin(GL_QUADS);

216 glColor3f(1, 1, 1);

217 glTexCoord1f(1);

218 glVertex2f(1, 0);

219 glVertex2f(1, 1);

220 glTexCoord1f(0);

221 glVertex2f(0, 1);

222 glVertex2f(0, 0);

223 glEnd();

224

225 glDisable(GL_TEXTURE_1D);

226

227 glLineWidth(2.0);

228 glBegin(GL_LINE_LOOP);

229 /*if(uimode == UIMODE_XFER) {

230 glColor3f(1, 0, 0);

231 } else {*/

232 glColor3f(0, 0, 1);

233 //}

234 glVertex2f(0, 0);

235 glVertex2f(1, 0);

236 glVertex2f(1, 1);

237 glVertex2f(0, 1);

238 glEnd();

239

240 glPopMatrix();

241 }

242

243 void volray_resize(int x, int y)

244 {

245 glViewport(0, 0, x, y);

246

247 if(x != win_xsz || y != win_ysz) {

248 raytex_needs_recalc = true;

249 win_xsz = x;

250 win_ysz = y;

251 }

252 }

253

254 #if 0

255 void keyb(unsigned char key, int x, int y)

256 {

257 switch(key) {

258 case 27:

259 exit(0);

260

261 case 'x':

262 uimode = UIMODE_XFER;

263 post_redisplay();

264 break;

265

266 case 'c':

267 uimode = UIMODE_CURSOR;

268 post_redisplay();

269 break;

270

271 default:

272 break;

273 }

274 }

275

276 void keyb_up(unsigned char key, int x, int y)

277 {

278 switch(key) {

279 case 'x':

280 if(uimode == UIMODE_XFER) {

281 uimode = UIMODE_DEFAULT;

282 post_redisplay();

283 }

284 break;

285

286 case 'c':

287 if(uimode == UIMODE_CURSOR) {

288 uimode = UIMODE_DEFAULT;

289 post_redisplay();

290 }

291 break;

292

293 default:

294 break;

295 }

296 }

297 #endif

298

299 static int bnstate[32];

300 static int prev_x, prev_y;

301

302 void volray_mouse(int bn, int state, int x, int y)

303 {

304 bnstate[bn] = state;

305 prev_x = x;

306 prev_y = y;

307 }

308

309 void volray_motion(int x, int y)

310 {

311 int dx = x - prev_x;

312 int dy = y - prev_y;

313 prev_x = x;

314 prev_y = y;

315

316 /*switch(uimode) {

317 case UIMODE_XFER:

318 if(dx || dy) {

319 xfer_mean += dx / (float)win_xsz;

320 xfer_sdev += 0.5 * dy / (float)win_ysz;

321

322 xfer_mean = xfer_mean < 0.0 ? 0.0 : (xfer_mean > 1.0 ? 1.0 : xfer_mean);

323 xfer_sdev = xfer_sdev < 0.0 ? 0.0 : (xfer_sdev > 1.0 ? 1.0 : xfer_sdev);

324

325 xfertex_needs_recalc = true;

326 post_redisplay();

327 }

328 break;

329

330 case UIMODE_CURSOR:

331 cur_z += 0.5 * dy / (float)win_ysz;

332

333 if(cur_z < 0.0)

334 cur_z = 0.0;

335 if(cur_z > 1.0)

336 cur_z = 1.0;

337

338 set_uniform_float(vol_sdr, "zclip", cur_z);

339 post_redisplay();

340 break;

341

342 default:*/

343 /* view control */

344 if(bnstate[0]) {

345 cam_theta += dx * 0.5;

346 cam_phi += dy * 0.5;

347

348 if(cam_phi <= -90) cam_phi = -89;

349 if(cam_phi >= 90) cam_phi = 89;

350 post_redisplay();

351 }

352

353 if(bnstate[1]) {

354 cam_x += dx * 0.025;

355 cam_y += dy * 0.025;

356 post_redisplay();

357 }

358

359 if(bnstate[2]) {

360 cam_dist += dy * 0.025;

361 if(cam_dist < 0.0) cam_dist = 0.0;

362 post_redisplay();

363 }

364 //}

365 }

366

367 #if 0

368 int parse_args(int argc, char **argv)

369 {

370 int i;

371 char *endp;

372

373 for(i=1; i<argc; i++) {

374 if(argv[i][0] == '-' && argv[i][2] == 0) {

375 switch(argv[i][1]) {

376 case 'm':

377 xfer_mean = strtod(argv[++i], &endp);

378 if(endp == argv[i]) {

379 fprintf(stderr, "-m must be followed by the transfer function mean\n");

380 return -1;

381 }

382 break;

383

384 case 'd':

385 xfer_sdev = strtod(argv[++i], &endp);

386 if(endp == argv[i]) {

387 fprintf(stderr, "-d must be followed by the transfer function std.deviation\n");

388 return -1;

389 }

390 break;

391

392 default:

393 fprintf(stderr, "unrecognized option: %s\n", argv[i]);

394 return -1;

395 }

396 } else {

397 if(fname) {

398 fprintf(stderr, "unexpected argument: %s\n", argv[i]);

399 return -1;

400 }

401 fname = argv[i];

402 }

403 }

404

405 if(!fname) {

406 fprintf(stderr, "pass the volume descriptor filename\n");

407 return -1;

408 }

409 return 0;

410 }

411 #endif

412

413

414 static void create_ray_texture(int xsz, int ysz, float vfov, Vector2 *tex_scale)

415 {

416 int cur_tex_xsz, cur_tex_ysz;

417 int tex_xsz = round_pow2(xsz);

418 int tex_ysz = round_pow2(ysz);

419 float *teximg, *dir;

420

421 teximg = new float[3 * xsz * ysz];

422 dir = teximg;

423

424 for(int i=0; i<ysz; i++) {

425 for(int j=0; j<xsz; j++) {

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

427 *dir++ = rdir.x;

428 *dir++ = rdir.y;

429 *dir++ = rdir.z;

430 }

431 }

432

433 if(!ray_tex) {

434 glGenTextures(1, &ray_tex);

435 }

436

437 glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_WIDTH, &cur_tex_xsz);

438 glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_HEIGHT, &cur_tex_ysz);

439

440 if(tex_xsz > cur_tex_xsz || tex_ysz > cur_tex_ysz) {

441 glBindTexture(GL_TEXTURE_2D, ray_tex);

442 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

443 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

444 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);

445 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);

446 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB32F_ARB, tex_xsz, tex_ysz, 0, GL_RGB, GL_FLOAT, 0);

447 }

448

449 glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, xsz, ysz, GL_RGB, GL_FLOAT, teximg);

450 delete [] teximg;

451

452 if(tex_scale) {

453 tex_scale->x = (float)xsz / (float)tex_xsz;

454 tex_scale->y = (float)ysz / (float)tex_ysz;

455 }

456 raytex_needs_recalc = false;

457 }

458

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

460 {

461 float vfov = M_PI * vfov_deg / 180.0;

462 float aspect = (float)w / (float)h;

463

464 float ysz = 2.0;

465 float xsz = aspect * ysz;

466

467 float px = ((float)x / (float)w) * xsz - xsz / 2.0;

468 float py = 1.0 - ((float)y / (float)h) * ysz;

469 float pz = 1.0 / tan(0.5 * vfov);

470

471 float mag = sqrt(px * px + py * py + pz * pz);

472 return Vector3(px / mag, py / mag, pz / mag);

473 }

474

475 static int round_pow2(int x)

476 {

477 x--;

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

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

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

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

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

483 return x + 1;

484 }

485

486 static void create_transfer_map(float mean, float sdev)

487 {

488 static float map[XFER_MAP_SZ];

489

490 if(!xfer_tex) {

491 glGenTextures(1, &xfer_tex);

492 glBindTexture(GL_TEXTURE_1D, xfer_tex);

493 glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

494 glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

495 glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);

496 glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

497 glTexImage1D(GL_TEXTURE_1D, 0, GL_LUMINANCE32F_ARB, XFER_MAP_SZ, 0, GL_LUMINANCE, GL_FLOAT, 0);

498 }

499

500 for(int i=0; i<XFER_MAP_SZ; i++) {

501 float x = (float)i / (float)(XFER_MAP_SZ - 1);

502 map[i] = gaussian(x, mean, sdev) - 1.0;

503 }

504

505 glTexSubImage1D(GL_TEXTURE_1D, 0, 0, XFER_MAP_SZ, GL_LUMINANCE, GL_FLOAT, map);

506 xfertex_needs_recalc = false;

507 }