qvolray

annotate src/volray.cc @ 36:70b937008134

find changesets by author, revision, files, or words in the commit message
demo :)
author John Tsiombikas <nuclear@member.fsf.org>
date Sun, 15 Apr 2012 07:19:01 +0300
parents 6ca076bf5084
children 450d4c50470f
rev   line source
nuclear@0 1 #include <stdio.h>
nuclear@0 2 #include <stdlib.h>
nuclear@0 3 #include <assert.h>
nuclear@0 4
nuclear@0 5 #include <GL/glew.h>
nuclear@0 6 #ifndef __APPLE__
nuclear@0 7 #include <GL/glut.h>
nuclear@0 8 #else
nuclear@0 9 #include <GLUT/glut.h>
nuclear@0 10 #endif
nuclear@0 11
nuclear@0 12 #include <vmath/vmath.h>
nuclear@0 13 #include <imago2.h>
nuclear@0 14 #include "sdr.h"
nuclear@9 15 #include "volume.h"
nuclear@13 16 #include "ui.h"
nuclear@18 17 #include "demo.h"
nuclear@0 18
nuclear@3 19 #define XFER_MAP_SZ 512
nuclear@3 20
nuclear@11 21 static void render_volume();
nuclear@5 22
nuclear@11 23 /*
nuclear@0 24 void keyb(unsigned char key, int x, int y);
nuclear@4 25 void keyb_up(unsigned char key, int x, int y);
nuclear@0 26 void mouse(int bn, int state, int x, int y);
nuclear@0 27 void motion(int x, int y);
nuclear@11 28 */
nuclear@0 29
nuclear@11 30 static void create_ray_texture(int xsz, int ysz, float vfov, Vector2 *tex_scale);
nuclear@11 31 static Vector3 get_primary_ray_dir(int x, int y, int w, int h, float vfov_deg);
nuclear@0 32 static int round_pow2(int x);
nuclear@3 33 static void create_transfer_map(float mean, float sdev);
nuclear@0 34
nuclear@9 35 static float cam_theta = 0, cam_phi = 0, cam_dist = 4.0;
nuclear@9 36 static float cam_x, cam_y, cam_z;
nuclear@0 37
nuclear@13 38 static Vector2 tex_scale;
nuclear@9 39 static unsigned int vol_sdr, slice_sdr, ray_tex;
nuclear@9 40 static int win_xsz, win_ysz;
nuclear@11 41 static bool raytex_needs_recalc = true;
nuclear@0 42
nuclear@9 43 static unsigned int xfer_tex;
nuclear@9 44 static float xfer_mean = 0.7, xfer_sdev = 0.1;
nuclear@11 45 static bool xfertex_needs_recalc = true;
nuclear@3 46
nuclear@19 47 static float cur_z = 0.5;
nuclear@23 48 static bool clip_z;
nuclear@7 49 static float ray_step = 0.01;
nuclear@4 50
nuclear@36 51 static Demo *demo;
nuclear@18 52 static Volume *volume;
nuclear@9 53
nuclear@33 54 static bool dbg_noray;
nuclear@33 55
nuclear@9 56
nuclear@11 57 bool volray_init()
nuclear@0 58 {
nuclear@0 59 glewInit();
nuclear@0 60
nuclear@9 61 if(!(vol_sdr = create_program_load("sdr/volray.v.glsl", "sdr/volray.p.glsl"))) {
nuclear@11 62 return false;
nuclear@0 63 }
nuclear@5 64 set_uniform_int(vol_sdr, "volume", 0);
nuclear@5 65 set_uniform_int(vol_sdr, "ray_tex", 1);
nuclear@5 66 set_uniform_int(vol_sdr, "xfer_tex", 2);
nuclear@7 67 set_uniform_float(vol_sdr, "ray_step", ray_step);
nuclear@23 68 set_uniform_float(vol_sdr, "zclip", 0.0);
nuclear@5 69
nuclear@9 70 if(!(slice_sdr = create_program_load(0, "sdr/slice.p.glsl"))) {
nuclear@11 71 return false;
nuclear@5 72 }
nuclear@5 73 set_uniform_int(slice_sdr, "volume", 0);
nuclear@5 74 set_uniform_int(slice_sdr, "xfer_tex", 1);
nuclear@0 75
nuclear@36 76 demo = new Demo;
nuclear@36 77 if(!demo->init()) {
nuclear@36 78 return false;
nuclear@36 79 }
nuclear@18 80
nuclear@11 81 return true;
nuclear@0 82 }
nuclear@0 83
nuclear@18 84 void volray_setvolume(Volume *vol)
nuclear@13 85 {
nuclear@13 86 volume = vol;
nuclear@13 87 }
nuclear@13 88
nuclear@18 89 Volume *volray_getvolume()
nuclear@18 90 {
nuclear@18 91 return volume;
nuclear@18 92 }
nuclear@18 93
nuclear@29 94 void volray_setvalue(VolRayOpt which, float val)
nuclear@21 95 {
nuclear@21 96 switch(which) {
nuclear@29 97 case VolRayOpt::ZCURSOR:
nuclear@21 98 cur_z = val;
nuclear@23 99 if(clip_z) {
nuclear@23 100 set_uniform_float(vol_sdr, "zclip", cur_z);
nuclear@23 101 }
nuclear@21 102 post_redisplay();
nuclear@21 103 break;
nuclear@21 104
nuclear@29 105 case VolRayOpt::ZCLIP:
nuclear@23 106 clip_z = val > 0.5;
nuclear@23 107 set_uniform_float(vol_sdr, "zclip", clip_z ? cur_z : 0.0);
nuclear@23 108 post_redisplay();
nuclear@23 109 break;
nuclear@22 110
nuclear@21 111 default:
nuclear@21 112 break;
nuclear@21 113 }
nuclear@21 114 }
nuclear@21 115
nuclear@29 116 float volray_getvalue(VolRayOpt which)
nuclear@21 117 {
nuclear@21 118 switch(which) {
nuclear@29 119 case VolRayOpt::ZCURSOR:
nuclear@21 120 return cur_z;
nuclear@21 121
nuclear@29 122 case VolRayOpt::ZCLIP:
nuclear@23 123 return clip_z > 0.5 ? 1.0 : 0.0;
nuclear@23 124 break;
nuclear@23 125
nuclear@21 126 default:
nuclear@21 127 break;
nuclear@21 128 }
nuclear@21 129 return 0.0;
nuclear@21 130 }
nuclear@21 131
nuclear@11 132 void volray_draw(void)
nuclear@0 133 {
nuclear@4 134 /* recalculate primary ray texture if needed */
nuclear@1 135 if(raytex_needs_recalc) {
nuclear@1 136 create_ray_texture(win_xsz, win_ysz, 50.0, &tex_scale);
nuclear@1 137 }
nuclear@4 138 /* recalculate transfer function texture if needed */
nuclear@3 139 if(xfertex_needs_recalc) {
nuclear@3 140 create_transfer_map(xfer_mean, xfer_sdev);
nuclear@3 141 }
nuclear@1 142
nuclear@33 143 glClear(GL_COLOR_BUFFER_BIT);
nuclear@33 144
nuclear@33 145 if(dbg_noray)
nuclear@33 146 return;
nuclear@33 147
nuclear@36 148 demo->draw();
nuclear@18 149
nuclear@13 150 if(volume) {
nuclear@13 151 render_volume();
nuclear@13 152 }
nuclear@4 153
nuclear@4 154 assert(glGetError() == GL_NO_ERROR);
nuclear@4 155 }
nuclear@4 156
nuclear@11 157 static void render_volume(void)
nuclear@4 158 {
nuclear@4 159 /* set the camera transformation */
nuclear@0 160 glMatrixMode(GL_MODELVIEW);
nuclear@4 161 glPushMatrix();
nuclear@0 162 glLoadIdentity();
nuclear@1 163 glRotatef(-90, 1, 0, 0);
nuclear@0 164 glTranslatef(cam_x, cam_y, -cam_z);
nuclear@0 165 glRotatef(cam_theta, 0, 1, 0);
nuclear@0 166 glRotatef(cam_phi, 1, 0, 0);
nuclear@0 167 glTranslatef(0, 0, -cam_dist);
nuclear@0 168
nuclear@4 169 /* setup the texture matrix to map the useful part of the ray texture to [0,1] */
nuclear@0 170 glMatrixMode(GL_TEXTURE);
nuclear@4 171 glPushMatrix();
nuclear@1 172 glLoadIdentity();
nuclear@0 173 glScalef(tex_scale.x, tex_scale.y, 1.0);
nuclear@0 174
nuclear@4 175 /* tex unit0: volume data 3D texture */
nuclear@0 176 glActiveTexture(GL_TEXTURE0);
nuclear@13 177 glBindTexture(GL_TEXTURE_3D, volume->get_texture());
nuclear@0 178 glEnable(GL_TEXTURE_3D);
nuclear@0 179
nuclear@4 180 /* tex unit1: primary rays in view space */
nuclear@0 181 glActiveTexture(GL_TEXTURE1);
nuclear@1 182 glBindTexture(GL_TEXTURE_2D, ray_tex);
nuclear@0 183 glEnable(GL_TEXTURE_2D);
nuclear@0 184
nuclear@4 185 /* tex unit2: transfer function (1d) */
nuclear@3 186 glActiveTexture(GL_TEXTURE2);
nuclear@3 187 glBindTexture(GL_TEXTURE_1D, xfer_tex);
nuclear@3 188 glEnable(GL_TEXTURE_1D);
nuclear@3 189
nuclear@5 190 bind_program(vol_sdr);
nuclear@0 191 glBegin(GL_QUADS);
nuclear@0 192 glColor3f(1, 1, 1);
nuclear@1 193 glTexCoord2f(0, 1); glVertex2f(-1, -1);
nuclear@1 194 glTexCoord2f(1, 1); glVertex2f(1, -1);
nuclear@1 195 glTexCoord2f(1, 0); glVertex2f(1, 1);
nuclear@1 196 glTexCoord2f(0, 0); glVertex2f(-1, 1);
nuclear@0 197 glEnd();
nuclear@0 198 bind_program(0);
nuclear@0 199
nuclear@3 200 glActiveTexture(GL_TEXTURE2);
nuclear@3 201 glDisable(GL_TEXTURE_1D);
nuclear@1 202 glActiveTexture(GL_TEXTURE1);
nuclear@0 203 glDisable(GL_TEXTURE_2D);
nuclear@0 204 glActiveTexture(GL_TEXTURE0);
nuclear@0 205 glDisable(GL_TEXTURE_3D);
nuclear@0 206
nuclear@0 207 glMatrixMode(GL_TEXTURE);
nuclear@4 208 glPopMatrix();
nuclear@4 209 glMatrixMode(GL_MODELVIEW);
nuclear@4 210 glPopMatrix();
nuclear@4 211 }
nuclear@0 212
nuclear@28 213 void volray_draw_slice(void)
nuclear@5 214 {
nuclear@33 215 glClear(GL_COLOR_BUFFER_BIT);
nuclear@33 216
nuclear@5 217 glActiveTexture(GL_TEXTURE0);
nuclear@13 218 glBindTexture(GL_TEXTURE_3D, volume->get_texture());
nuclear@5 219 glEnable(GL_TEXTURE_3D);
nuclear@5 220
nuclear@5 221 glActiveTexture(GL_TEXTURE1);
nuclear@5 222 glBindTexture(GL_TEXTURE_1D, xfer_tex);
nuclear@5 223 glEnable(GL_TEXTURE_1D);
nuclear@5 224
nuclear@5 225 bind_program(slice_sdr);
nuclear@5 226
nuclear@5 227 glBegin(GL_QUADS);
nuclear@5 228 glColor3f(1, 1, 1);
nuclear@5 229 glTexCoord3f(0, 1, cur_z); glVertex2f(-1, -1);
nuclear@5 230 glTexCoord3f(1, 1, cur_z); glVertex2f(1, -1);
nuclear@5 231 glTexCoord3f(1, 0, cur_z); glVertex2f(1, 1);
nuclear@5 232 glTexCoord3f(0, 0, cur_z); glVertex2f(-1, 1);
nuclear@5 233 glEnd();
nuclear@5 234
nuclear@5 235 bind_program(0);
nuclear@5 236
nuclear@5 237 glActiveTexture(GL_TEXTURE1);
nuclear@5 238 glDisable(GL_TEXTURE_1D);
nuclear@5 239 glActiveTexture(GL_TEXTURE0);
nuclear@5 240 glDisable(GL_TEXTURE_3D);
nuclear@5 241 }
nuclear@5 242
nuclear@29 243 void volray_draw_xfer(void)
nuclear@4 244 {
nuclear@33 245 glClear(GL_COLOR_BUFFER_BIT);
nuclear@33 246
nuclear@4 247 glMatrixMode(GL_MODELVIEW);
nuclear@4 248 glPushMatrix();
nuclear@30 249 glTranslatef(-1, -1, 0);
nuclear@30 250 glScalef(2, 2, 1);
nuclear@4 251
nuclear@4 252 glBindTexture(GL_TEXTURE_1D, xfer_tex);
nuclear@4 253 glEnable(GL_TEXTURE_1D);
nuclear@4 254
nuclear@4 255 glBegin(GL_QUADS);
nuclear@4 256 glColor3f(1, 1, 1);
nuclear@4 257 glTexCoord1f(1);
nuclear@4 258 glVertex2f(1, 0);
nuclear@4 259 glVertex2f(1, 1);
nuclear@4 260 glTexCoord1f(0);
nuclear@4 261 glVertex2f(0, 1);
nuclear@4 262 glVertex2f(0, 0);
nuclear@4 263 glEnd();
nuclear@4 264
nuclear@4 265 glDisable(GL_TEXTURE_1D);
nuclear@4 266 glPopMatrix();
nuclear@0 267 }
nuclear@0 268
nuclear@11 269 void volray_resize(int x, int y)
nuclear@0 270 {
nuclear@0 271 glViewport(0, 0, x, y);
nuclear@0 272
nuclear@0 273 if(x != win_xsz || y != win_ysz) {
nuclear@11 274 raytex_needs_recalc = true;
nuclear@0 275 win_xsz = x;
nuclear@0 276 win_ysz = y;
nuclear@0 277 }
nuclear@0 278 }
nuclear@0 279
nuclear@11 280 #if 0
nuclear@0 281 void keyb(unsigned char key, int x, int y)
nuclear@0 282 {
nuclear@0 283 switch(key) {
nuclear@0 284 case 27:
nuclear@0 285 exit(0);
nuclear@4 286
nuclear@4 287 case 'x':
nuclear@5 288 uimode = UIMODE_XFER;
nuclear@13 289 post_redisplay();
nuclear@4 290 break;
nuclear@5 291
nuclear@5 292 case 'c':
nuclear@5 293 uimode = UIMODE_CURSOR;
nuclear@13 294 post_redisplay();
nuclear@5 295 break;
nuclear@5 296
nuclear@5 297 default:
nuclear@5 298 break;
nuclear@4 299 }
nuclear@4 300 }
nuclear@4 301
nuclear@4 302 void keyb_up(unsigned char key, int x, int y)
nuclear@4 303 {
nuclear@4 304 switch(key) {
nuclear@4 305 case 'x':
nuclear@5 306 if(uimode == UIMODE_XFER) {
nuclear@5 307 uimode = UIMODE_DEFAULT;
nuclear@13 308 post_redisplay();
nuclear@5 309 }
nuclear@5 310 break;
nuclear@5 311
nuclear@5 312 case 'c':
nuclear@5 313 if(uimode == UIMODE_CURSOR) {
nuclear@5 314 uimode = UIMODE_DEFAULT;
nuclear@13 315 post_redisplay();
nuclear@5 316 }
nuclear@5 317 break;
nuclear@5 318
nuclear@5 319 default:
nuclear@4 320 break;
nuclear@0 321 }
nuclear@0 322 }
nuclear@13 323 #endif
nuclear@0 324
nuclear@0 325 static int bnstate[32];
nuclear@0 326 static int prev_x, prev_y;
nuclear@0 327
nuclear@13 328 void volray_mouse(int bn, int state, int x, int y)
nuclear@0 329 {
nuclear@13 330 bnstate[bn] = state;
nuclear@0 331 prev_x = x;
nuclear@0 332 prev_y = y;
nuclear@0 333 }
nuclear@0 334
nuclear@35 335 void modxfer(int dx, int dy, int max_x, int max_y)
nuclear@35 336 {
nuclear@35 337 if(!dx && !dy)
nuclear@35 338 return;
nuclear@35 339
nuclear@35 340 xfer_mean += dx / (float)max_x;
nuclear@35 341 xfer_sdev += 0.5 * dy / (float)max_y;
nuclear@35 342
nuclear@35 343 xfer_mean = xfer_mean < 0.0 ? 0.0 : (xfer_mean > 1.0 ? 1.0 : xfer_mean);
nuclear@35 344 xfer_sdev = xfer_sdev < 0.0 ? 0.0 : (xfer_sdev > 1.0 ? 1.0 : xfer_sdev);
nuclear@35 345
nuclear@35 346 xfertex_needs_recalc = true;
nuclear@35 347 post_redisplay();
nuclear@35 348 }
nuclear@35 349
nuclear@13 350 void volray_motion(int x, int y)
nuclear@0 351 {
nuclear@0 352 int dx = x - prev_x;
nuclear@0 353 int dy = y - prev_y;
nuclear@0 354 prev_x = x;
nuclear@0 355 prev_y = y;
nuclear@0 356
nuclear@13 357 /*switch(uimode) {
nuclear@5 358 case UIMODE_XFER:
nuclear@5 359 break;
nuclear@0 360
nuclear@5 361 case UIMODE_CURSOR:
nuclear@5 362 cur_z += 0.5 * dy / (float)win_ysz;
nuclear@5 363
nuclear@5 364 if(cur_z < 0.0)
nuclear@5 365 cur_z = 0.0;
nuclear@5 366 if(cur_z > 1.0)
nuclear@5 367 cur_z = 1.0;
nuclear@7 368
nuclear@7 369 set_uniform_float(vol_sdr, "zclip", cur_z);
nuclear@13 370 post_redisplay();
nuclear@5 371 break;
nuclear@5 372
nuclear@13 373 default:*/
nuclear@5 374 /* view control */
nuclear@4 375 if(bnstate[0]) {
nuclear@4 376 cam_theta += dx * 0.5;
nuclear@4 377 cam_phi += dy * 0.5;
nuclear@0 378
nuclear@4 379 if(cam_phi <= -90) cam_phi = -89;
nuclear@4 380 if(cam_phi >= 90) cam_phi = 89;
nuclear@13 381 post_redisplay();
nuclear@4 382 }
nuclear@4 383
nuclear@4 384 if(bnstate[1]) {
nuclear@4 385 cam_x += dx * 0.025;
nuclear@4 386 cam_y += dy * 0.025;
nuclear@13 387 post_redisplay();
nuclear@4 388 }
nuclear@4 389
nuclear@4 390 if(bnstate[2]) {
nuclear@4 391 cam_dist += dy * 0.025;
nuclear@4 392 if(cam_dist < 0.0) cam_dist = 0.0;
nuclear@13 393 post_redisplay();
nuclear@4 394 }
nuclear@13 395 //}
nuclear@0 396 }
nuclear@0 397
nuclear@0 398 int parse_args(int argc, char **argv)
nuclear@0 399 {
nuclear@0 400 int i;
nuclear@3 401 char *endp;
nuclear@0 402
nuclear@0 403 for(i=1; i<argc; i++) {
nuclear@2 404 if(argv[i][0] == '-' && argv[i][2] == 0) {
nuclear@2 405 switch(argv[i][1]) {
nuclear@3 406 case 'm':
nuclear@3 407 xfer_mean = strtod(argv[++i], &endp);
nuclear@3 408 if(endp == argv[i]) {
nuclear@3 409 fprintf(stderr, "-m must be followed by the transfer function mean\n");
nuclear@3 410 return -1;
nuclear@3 411 }
nuclear@2 412 break;
nuclear@3 413
nuclear@4 414 case 'd':
nuclear@3 415 xfer_sdev = strtod(argv[++i], &endp);
nuclear@3 416 if(endp == argv[i]) {
nuclear@4 417 fprintf(stderr, "-d must be followed by the transfer function std.deviation\n");
nuclear@3 418 return -1;
nuclear@3 419 }
nuclear@3 420 break;
nuclear@3 421
nuclear@3 422 default:
nuclear@3 423 fprintf(stderr, "unrecognized option: %s\n", argv[i]);
nuclear@3 424 return -1;
nuclear@2 425 }
nuclear@2 426 } else {
nuclear@29 427 fprintf(stderr, "unexpected argument: %s\n", argv[i]);
nuclear@0 428 }
nuclear@0 429 }
nuclear@0 430
nuclear@33 431 if(getenv("DBG_NORAY")) {
nuclear@33 432 dbg_noray = true;
nuclear@33 433 }
nuclear@0 434 return 0;
nuclear@0 435 }
nuclear@0 436
nuclear@0 437
nuclear@11 438 static void create_ray_texture(int xsz, int ysz, float vfov, Vector2 *tex_scale)
nuclear@0 439 {
nuclear@1 440 int cur_tex_xsz, cur_tex_ysz;
nuclear@0 441 int tex_xsz = round_pow2(xsz);
nuclear@0 442 int tex_ysz = round_pow2(ysz);
nuclear@0 443 float *teximg, *dir;
nuclear@0 444
nuclear@11 445 teximg = new float[3 * xsz * ysz];
nuclear@0 446 dir = teximg;
nuclear@0 447
nuclear@11 448 for(int i=0; i<ysz; i++) {
nuclear@11 449 for(int j=0; j<xsz; j++) {
nuclear@11 450 Vector3 rdir = get_primary_ray_dir(j, i, xsz, ysz, vfov);
nuclear@1 451 *dir++ = rdir.x;
nuclear@1 452 *dir++ = rdir.y;
nuclear@1 453 *dir++ = rdir.z;
nuclear@0 454 }
nuclear@0 455 }
nuclear@0 456
nuclear@1 457 if(!ray_tex) {
nuclear@1 458 glGenTextures(1, &ray_tex);
nuclear@1 459 }
nuclear@1 460
nuclear@1 461 glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_WIDTH, &cur_tex_xsz);
nuclear@1 462 glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_HEIGHT, &cur_tex_ysz);
nuclear@1 463
nuclear@1 464 if(tex_xsz > cur_tex_xsz || tex_ysz > cur_tex_ysz) {
nuclear@1 465 glBindTexture(GL_TEXTURE_2D, ray_tex);
nuclear@1 466 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
nuclear@1 467 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
nuclear@1 468 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
nuclear@1 469 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
nuclear@1 470 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB32F_ARB, tex_xsz, tex_ysz, 0, GL_RGB, GL_FLOAT, 0);
nuclear@1 471 }
nuclear@1 472
nuclear@1 473 glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, xsz, ysz, GL_RGB, GL_FLOAT, teximg);
nuclear@11 474 delete [] teximg;
nuclear@0 475
nuclear@0 476 if(tex_scale) {
nuclear@0 477 tex_scale->x = (float)xsz / (float)tex_xsz;
nuclear@0 478 tex_scale->y = (float)ysz / (float)tex_ysz;
nuclear@0 479 }
nuclear@11 480 raytex_needs_recalc = false;
nuclear@0 481 }
nuclear@0 482
nuclear@11 483 static Vector3 get_primary_ray_dir(int x, int y, int w, int h, float vfov_deg)
nuclear@0 484 {
nuclear@0 485 float vfov = M_PI * vfov_deg / 180.0;
nuclear@0 486 float aspect = (float)w / (float)h;
nuclear@0 487
nuclear@0 488 float ysz = 2.0;
nuclear@0 489 float xsz = aspect * ysz;
nuclear@0 490
nuclear@0 491 float px = ((float)x / (float)w) * xsz - xsz / 2.0;
nuclear@0 492 float py = 1.0 - ((float)y / (float)h) * ysz;
nuclear@0 493 float pz = 1.0 / tan(0.5 * vfov);
nuclear@0 494
nuclear@0 495 float mag = sqrt(px * px + py * py + pz * pz);
nuclear@11 496 return Vector3(px / mag, py / mag, pz / mag);
nuclear@0 497 }
nuclear@0 498
nuclear@0 499 static int round_pow2(int x)
nuclear@0 500 {
nuclear@0 501 x--;
nuclear@0 502 x = (x >> 1) | x;
nuclear@0 503 x = (x >> 2) | x;
nuclear@0 504 x = (x >> 4) | x;
nuclear@0 505 x = (x >> 8) | x;
nuclear@0 506 x = (x >> 16) | x;
nuclear@0 507 return x + 1;
nuclear@0 508 }
nuclear@0 509
nuclear@3 510 static void create_transfer_map(float mean, float sdev)
nuclear@3 511 {
nuclear@3 512 static float map[XFER_MAP_SZ];
nuclear@3 513
nuclear@3 514 if(!xfer_tex) {
nuclear@3 515 glGenTextures(1, &xfer_tex);
nuclear@3 516 glBindTexture(GL_TEXTURE_1D, xfer_tex);
nuclear@3 517 glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
nuclear@3 518 glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
nuclear@3 519 glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
nuclear@3 520 glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
nuclear@3 521 glTexImage1D(GL_TEXTURE_1D, 0, GL_LUMINANCE32F_ARB, XFER_MAP_SZ, 0, GL_LUMINANCE, GL_FLOAT, 0);
nuclear@3 522 }
nuclear@3 523
nuclear@11 524 for(int i=0; i<XFER_MAP_SZ; i++) {
nuclear@4 525 float x = (float)i / (float)(XFER_MAP_SZ - 1);
nuclear@4 526 map[i] = gaussian(x, mean, sdev) - 1.0;
nuclear@3 527 }
nuclear@3 528
nuclear@4 529 glTexSubImage1D(GL_TEXTURE_1D, 0, 0, XFER_MAP_SZ, GL_LUMINANCE, GL_FLOAT, map);
nuclear@11 530 xfertex_needs_recalc = false;
nuclear@3 531 }