qvolray

annotate src/volray.cc @ 21:4c62be57fc1a

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foo
author John Tsiombikas <nuclear@member.fsf.org>
date Wed, 11 Apr 2012 16:59:45 +0300
parents 784d3d321caa
children 2d0dfb5751dc
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@11 22 static void draw_slice();
nuclear@11 23 static void draw_xfer_func();
nuclear@5 24
nuclear@11 25 /*
nuclear@0 26 void keyb(unsigned char key, int x, int y);
nuclear@4 27 void keyb_up(unsigned char key, int x, int y);
nuclear@0 28 void mouse(int bn, int state, int x, int y);
nuclear@0 29 void motion(int x, int y);
nuclear@0 30 int parse_args(int argc, char **argv);
nuclear@11 31 */
nuclear@0 32
nuclear@11 33 static void create_ray_texture(int xsz, int ysz, float vfov, Vector2 *tex_scale);
nuclear@11 34 static Vector3 get_primary_ray_dir(int x, int y, int w, int h, float vfov_deg);
nuclear@0 35 static int round_pow2(int x);
nuclear@3 36 static void create_transfer_map(float mean, float sdev);
nuclear@0 37
nuclear@9 38 static float cam_theta = 0, cam_phi = 0, cam_dist = 4.0;
nuclear@9 39 static float cam_x, cam_y, cam_z;
nuclear@0 40
nuclear@13 41 static Vector2 tex_scale;
nuclear@9 42 static unsigned int vol_sdr, slice_sdr, ray_tex;
nuclear@9 43 static int win_xsz, win_ysz;
nuclear@11 44 static bool raytex_needs_recalc = true;
nuclear@0 45
nuclear@9 46 static unsigned int xfer_tex;
nuclear@9 47 static float xfer_mean = 0.7, xfer_sdev = 0.1;
nuclear@11 48 static bool xfertex_needs_recalc = true;
nuclear@3 49
nuclear@19 50 static float cur_z = 0.5;
nuclear@7 51 static float ray_step = 0.01;
nuclear@4 52
nuclear@18 53 static Volume *volume;
nuclear@9 54
nuclear@9 55
nuclear@11 56 bool volray_init()
nuclear@0 57 {
nuclear@0 58 glewInit();
nuclear@0 59
nuclear@9 60 if(!(vol_sdr = create_program_load("sdr/volray.v.glsl", "sdr/volray.p.glsl"))) {
nuclear@11 61 return false;
nuclear@0 62 }
nuclear@5 63 set_uniform_int(vol_sdr, "volume", 0);
nuclear@5 64 set_uniform_int(vol_sdr, "ray_tex", 1);
nuclear@5 65 set_uniform_int(vol_sdr, "xfer_tex", 2);
nuclear@7 66 set_uniform_float(vol_sdr, "ray_step", ray_step);
nuclear@7 67 set_uniform_float(vol_sdr, "zclip", cur_z);
nuclear@5 68
nuclear@9 69 if(!(slice_sdr = create_program_load(0, "sdr/slice.p.glsl"))) {
nuclear@11 70 return false;
nuclear@5 71 }
nuclear@5 72 set_uniform_int(slice_sdr, "volume", 0);
nuclear@5 73 set_uniform_int(slice_sdr, "xfer_tex", 1);
nuclear@0 74
nuclear@18 75 init_demo();
nuclear@18 76
nuclear@11 77 return true;
nuclear@0 78 }
nuclear@0 79
nuclear@18 80 void volray_setvolume(Volume *vol)
nuclear@13 81 {
nuclear@13 82 volume = vol;
nuclear@13 83 }
nuclear@13 84
nuclear@18 85 Volume *volray_getvolume()
nuclear@18 86 {
nuclear@18 87 return volume;
nuclear@18 88 }
nuclear@18 89
nuclear@21 90 void volray_setvalue(int which, float val)
nuclear@21 91 {
nuclear@21 92 switch(which) {
nuclear@21 93 case VOLRAY_ZCURSOR:
nuclear@21 94 cur_z = val;
nuclear@21 95 set_uniform_float(vol_sdr, "zclip", cur_z);
nuclear@21 96 post_redisplay();
nuclear@21 97 break;
nuclear@21 98
nuclear@21 99 default:
nuclear@21 100 break;
nuclear@21 101 }
nuclear@21 102 }
nuclear@21 103
nuclear@21 104 float volray_getvalue(int which)
nuclear@21 105 {
nuclear@21 106 switch(which) {
nuclear@21 107 case VOLRAY_ZCURSOR:
nuclear@21 108 return cur_z;
nuclear@21 109
nuclear@21 110 default:
nuclear@21 111 break;
nuclear@21 112 }
nuclear@21 113 return 0.0;
nuclear@21 114 }
nuclear@21 115
nuclear@11 116 void volray_draw(void)
nuclear@0 117 {
nuclear@4 118 /* recalculate primary ray texture if needed */
nuclear@1 119 if(raytex_needs_recalc) {
nuclear@1 120 create_ray_texture(win_xsz, win_ysz, 50.0, &tex_scale);
nuclear@1 121 }
nuclear@4 122 /* recalculate transfer function texture if needed */
nuclear@3 123 if(xfertex_needs_recalc) {
nuclear@3 124 create_transfer_map(xfer_mean, xfer_sdev);
nuclear@3 125 }
nuclear@1 126
nuclear@18 127 draw_demo();
nuclear@18 128
nuclear@13 129 glClear(GL_COLOR_BUFFER_BIT);
nuclear@13 130
nuclear@13 131 if(volume) {
nuclear@13 132 render_volume();
nuclear@13 133 draw_slice();
nuclear@13 134 draw_xfer_func();
nuclear@13 135 }
nuclear@4 136
nuclear@4 137 assert(glGetError() == GL_NO_ERROR);
nuclear@4 138 }
nuclear@4 139
nuclear@11 140 static void render_volume(void)
nuclear@4 141 {
nuclear@4 142 /* set the camera transformation */
nuclear@0 143 glMatrixMode(GL_MODELVIEW);
nuclear@4 144 glPushMatrix();
nuclear@0 145 glLoadIdentity();
nuclear@1 146 glRotatef(-90, 1, 0, 0);
nuclear@0 147 glTranslatef(cam_x, cam_y, -cam_z);
nuclear@0 148 glRotatef(cam_theta, 0, 1, 0);
nuclear@0 149 glRotatef(cam_phi, 1, 0, 0);
nuclear@0 150 glTranslatef(0, 0, -cam_dist);
nuclear@0 151
nuclear@4 152 /* setup the texture matrix to map the useful part of the ray texture to [0,1] */
nuclear@0 153 glMatrixMode(GL_TEXTURE);
nuclear@4 154 glPushMatrix();
nuclear@1 155 glLoadIdentity();
nuclear@0 156 glScalef(tex_scale.x, tex_scale.y, 1.0);
nuclear@0 157
nuclear@4 158 /* tex unit0: volume data 3D texture */
nuclear@0 159 glActiveTexture(GL_TEXTURE0);
nuclear@13 160 glBindTexture(GL_TEXTURE_3D, volume->get_texture());
nuclear@0 161 glEnable(GL_TEXTURE_3D);
nuclear@0 162
nuclear@4 163 /* tex unit1: primary rays in view space */
nuclear@0 164 glActiveTexture(GL_TEXTURE1);
nuclear@1 165 glBindTexture(GL_TEXTURE_2D, ray_tex);
nuclear@0 166 glEnable(GL_TEXTURE_2D);
nuclear@0 167
nuclear@4 168 /* tex unit2: transfer function (1d) */
nuclear@3 169 glActiveTexture(GL_TEXTURE2);
nuclear@3 170 glBindTexture(GL_TEXTURE_1D, xfer_tex);
nuclear@3 171 glEnable(GL_TEXTURE_1D);
nuclear@3 172
nuclear@5 173 bind_program(vol_sdr);
nuclear@0 174 glBegin(GL_QUADS);
nuclear@0 175 glColor3f(1, 1, 1);
nuclear@1 176 glTexCoord2f(0, 1); glVertex2f(-1, -1);
nuclear@1 177 glTexCoord2f(1, 1); glVertex2f(1, -1);
nuclear@1 178 glTexCoord2f(1, 0); glVertex2f(1, 1);
nuclear@1 179 glTexCoord2f(0, 0); glVertex2f(-1, 1);
nuclear@0 180 glEnd();
nuclear@0 181 bind_program(0);
nuclear@0 182
nuclear@3 183 glActiveTexture(GL_TEXTURE2);
nuclear@3 184 glDisable(GL_TEXTURE_1D);
nuclear@1 185 glActiveTexture(GL_TEXTURE1);
nuclear@0 186 glDisable(GL_TEXTURE_2D);
nuclear@0 187 glActiveTexture(GL_TEXTURE0);
nuclear@0 188 glDisable(GL_TEXTURE_3D);
nuclear@0 189
nuclear@0 190 glMatrixMode(GL_TEXTURE);
nuclear@4 191 glPopMatrix();
nuclear@4 192 glMatrixMode(GL_MODELVIEW);
nuclear@4 193 glPopMatrix();
nuclear@4 194 }
nuclear@0 195
nuclear@11 196 static void draw_slice(void)
nuclear@5 197 {
nuclear@5 198 glMatrixMode(GL_MODELVIEW);
nuclear@5 199 glPushMatrix();
nuclear@5 200 glTranslatef(0.9, 0.9, 0);
nuclear@5 201 glScalef(0.3, 0.3 * ((float)win_xsz / win_ysz), 1);
nuclear@5 202 glTranslatef(-1, -1, 0);
nuclear@5 203
nuclear@5 204 glActiveTexture(GL_TEXTURE0);
nuclear@13 205 glBindTexture(GL_TEXTURE_3D, volume->get_texture());
nuclear@5 206 glEnable(GL_TEXTURE_3D);
nuclear@5 207
nuclear@5 208 glActiveTexture(GL_TEXTURE1);
nuclear@5 209 glBindTexture(GL_TEXTURE_1D, xfer_tex);
nuclear@5 210 glEnable(GL_TEXTURE_1D);
nuclear@5 211
nuclear@5 212 bind_program(slice_sdr);
nuclear@5 213
nuclear@5 214 glBegin(GL_QUADS);
nuclear@5 215 glColor3f(1, 1, 1);
nuclear@5 216 glTexCoord3f(0, 1, cur_z); glVertex2f(-1, -1);
nuclear@5 217 glTexCoord3f(1, 1, cur_z); glVertex2f(1, -1);
nuclear@5 218 glTexCoord3f(1, 0, cur_z); glVertex2f(1, 1);
nuclear@5 219 glTexCoord3f(0, 0, cur_z); glVertex2f(-1, 1);
nuclear@5 220 glEnd();
nuclear@5 221
nuclear@5 222 bind_program(0);
nuclear@5 223
nuclear@5 224 glActiveTexture(GL_TEXTURE1);
nuclear@5 225 glDisable(GL_TEXTURE_1D);
nuclear@5 226 glActiveTexture(GL_TEXTURE0);
nuclear@5 227 glDisable(GL_TEXTURE_3D);
nuclear@5 228 glPopMatrix();
nuclear@5 229 }
nuclear@5 230
nuclear@11 231 static void draw_xfer_func(void)
nuclear@4 232 {
nuclear@4 233 glMatrixMode(GL_MODELVIEW);
nuclear@4 234 glPushMatrix();
nuclear@4 235 glTranslatef(-0.9, -0.9, 0);
nuclear@4 236 glScalef(0.5, 0.1, 1);
nuclear@4 237
nuclear@4 238 glBindTexture(GL_TEXTURE_1D, xfer_tex);
nuclear@4 239 glEnable(GL_TEXTURE_1D);
nuclear@4 240
nuclear@4 241 glBegin(GL_QUADS);
nuclear@4 242 glColor3f(1, 1, 1);
nuclear@4 243 glTexCoord1f(1);
nuclear@4 244 glVertex2f(1, 0);
nuclear@4 245 glVertex2f(1, 1);
nuclear@4 246 glTexCoord1f(0);
nuclear@4 247 glVertex2f(0, 1);
nuclear@4 248 glVertex2f(0, 0);
nuclear@4 249 glEnd();
nuclear@4 250
nuclear@4 251 glDisable(GL_TEXTURE_1D);
nuclear@4 252
nuclear@4 253 glLineWidth(2.0);
nuclear@4 254 glBegin(GL_LINE_LOOP);
nuclear@13 255 /*if(uimode == UIMODE_XFER) {
nuclear@5 256 glColor3f(1, 0, 0);
nuclear@13 257 } else {*/
nuclear@5 258 glColor3f(0, 0, 1);
nuclear@13 259 //}
nuclear@4 260 glVertex2f(0, 0);
nuclear@4 261 glVertex2f(1, 0);
nuclear@4 262 glVertex2f(1, 1);
nuclear@4 263 glVertex2f(0, 1);
nuclear@4 264 glEnd();
nuclear@4 265
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@13 335 void volray_motion(int x, int y)
nuclear@0 336 {
nuclear@0 337 int dx = x - prev_x;
nuclear@0 338 int dy = y - prev_y;
nuclear@0 339 prev_x = x;
nuclear@0 340 prev_y = y;
nuclear@0 341
nuclear@13 342 /*switch(uimode) {
nuclear@5 343 case UIMODE_XFER:
nuclear@4 344 if(dx || dy) {
nuclear@4 345 xfer_mean += dx / (float)win_xsz;
nuclear@4 346 xfer_sdev += 0.5 * dy / (float)win_ysz;
nuclear@0 347
nuclear@4 348 xfer_mean = xfer_mean < 0.0 ? 0.0 : (xfer_mean > 1.0 ? 1.0 : xfer_mean);
nuclear@4 349 xfer_sdev = xfer_sdev < 0.0 ? 0.0 : (xfer_sdev > 1.0 ? 1.0 : xfer_sdev);
nuclear@0 350
nuclear@11 351 xfertex_needs_recalc = true;
nuclear@13 352 post_redisplay();
nuclear@4 353 }
nuclear@5 354 break;
nuclear@0 355
nuclear@5 356 case UIMODE_CURSOR:
nuclear@5 357 cur_z += 0.5 * dy / (float)win_ysz;
nuclear@5 358
nuclear@5 359 if(cur_z < 0.0)
nuclear@5 360 cur_z = 0.0;
nuclear@5 361 if(cur_z > 1.0)
nuclear@5 362 cur_z = 1.0;
nuclear@7 363
nuclear@7 364 set_uniform_float(vol_sdr, "zclip", cur_z);
nuclear@13 365 post_redisplay();
nuclear@5 366 break;
nuclear@5 367
nuclear@13 368 default:*/
nuclear@5 369 /* view control */
nuclear@4 370 if(bnstate[0]) {
nuclear@4 371 cam_theta += dx * 0.5;
nuclear@4 372 cam_phi += dy * 0.5;
nuclear@0 373
nuclear@4 374 if(cam_phi <= -90) cam_phi = -89;
nuclear@4 375 if(cam_phi >= 90) cam_phi = 89;
nuclear@13 376 post_redisplay();
nuclear@4 377 }
nuclear@4 378
nuclear@4 379 if(bnstate[1]) {
nuclear@4 380 cam_x += dx * 0.025;
nuclear@4 381 cam_y += dy * 0.025;
nuclear@13 382 post_redisplay();
nuclear@4 383 }
nuclear@4 384
nuclear@4 385 if(bnstate[2]) {
nuclear@4 386 cam_dist += dy * 0.025;
nuclear@4 387 if(cam_dist < 0.0) cam_dist = 0.0;
nuclear@13 388 post_redisplay();
nuclear@4 389 }
nuclear@13 390 //}
nuclear@0 391 }
nuclear@0 392
nuclear@13 393 #if 0
nuclear@0 394 int parse_args(int argc, char **argv)
nuclear@0 395 {
nuclear@0 396 int i;
nuclear@3 397 char *endp;
nuclear@0 398
nuclear@0 399 for(i=1; i<argc; i++) {
nuclear@2 400 if(argv[i][0] == '-' && argv[i][2] == 0) {
nuclear@2 401 switch(argv[i][1]) {
nuclear@3 402 case 'm':
nuclear@3 403 xfer_mean = strtod(argv[++i], &endp);
nuclear@3 404 if(endp == argv[i]) {
nuclear@3 405 fprintf(stderr, "-m must be followed by the transfer function mean\n");
nuclear@3 406 return -1;
nuclear@3 407 }
nuclear@2 408 break;
nuclear@3 409
nuclear@4 410 case 'd':
nuclear@3 411 xfer_sdev = strtod(argv[++i], &endp);
nuclear@3 412 if(endp == argv[i]) {
nuclear@4 413 fprintf(stderr, "-d must be followed by the transfer function std.deviation\n");
nuclear@3 414 return -1;
nuclear@3 415 }
nuclear@3 416 break;
nuclear@3 417
nuclear@3 418 default:
nuclear@3 419 fprintf(stderr, "unrecognized option: %s\n", argv[i]);
nuclear@3 420 return -1;
nuclear@2 421 }
nuclear@2 422 } else {
nuclear@9 423 if(fname) {
nuclear@9 424 fprintf(stderr, "unexpected argument: %s\n", argv[i]);
nuclear@2 425 return -1;
nuclear@2 426 }
nuclear@9 427 fname = argv[i];
nuclear@0 428 }
nuclear@0 429 }
nuclear@0 430
nuclear@9 431 if(!fname) {
nuclear@9 432 fprintf(stderr, "pass the volume descriptor filename\n");
nuclear@0 433 return -1;
nuclear@0 434 }
nuclear@0 435 return 0;
nuclear@0 436 }
nuclear@11 437 #endif
nuclear@0 438
nuclear@0 439
nuclear@11 440 static void create_ray_texture(int xsz, int ysz, float vfov, Vector2 *tex_scale)
nuclear@0 441 {
nuclear@1 442 int cur_tex_xsz, cur_tex_ysz;
nuclear@0 443 int tex_xsz = round_pow2(xsz);
nuclear@0 444 int tex_ysz = round_pow2(ysz);
nuclear@0 445 float *teximg, *dir;
nuclear@0 446
nuclear@11 447 teximg = new float[3 * xsz * ysz];
nuclear@0 448 dir = teximg;
nuclear@0 449
nuclear@11 450 for(int i=0; i<ysz; i++) {
nuclear@11 451 for(int j=0; j<xsz; j++) {
nuclear@11 452 Vector3 rdir = get_primary_ray_dir(j, i, xsz, ysz, vfov);
nuclear@1 453 *dir++ = rdir.x;
nuclear@1 454 *dir++ = rdir.y;
nuclear@1 455 *dir++ = rdir.z;
nuclear@0 456 }
nuclear@0 457 }
nuclear@0 458
nuclear@1 459 if(!ray_tex) {
nuclear@1 460 glGenTextures(1, &ray_tex);
nuclear@1 461 }
nuclear@1 462
nuclear@1 463 glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_WIDTH, &cur_tex_xsz);
nuclear@1 464 glGetTexLevelParameteriv(GL_TEXTURE_2D, 0, GL_TEXTURE_HEIGHT, &cur_tex_ysz);
nuclear@1 465
nuclear@1 466 if(tex_xsz > cur_tex_xsz || tex_ysz > cur_tex_ysz) {
nuclear@1 467 glBindTexture(GL_TEXTURE_2D, ray_tex);
nuclear@1 468 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
nuclear@1 469 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
nuclear@1 470 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
nuclear@1 471 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
nuclear@1 472 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB32F_ARB, tex_xsz, tex_ysz, 0, GL_RGB, GL_FLOAT, 0);
nuclear@1 473 }
nuclear@1 474
nuclear@1 475 glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, xsz, ysz, GL_RGB, GL_FLOAT, teximg);
nuclear@11 476 delete [] teximg;
nuclear@0 477
nuclear@0 478 if(tex_scale) {
nuclear@0 479 tex_scale->x = (float)xsz / (float)tex_xsz;
nuclear@0 480 tex_scale->y = (float)ysz / (float)tex_ysz;
nuclear@0 481 }
nuclear@11 482 raytex_needs_recalc = false;
nuclear@0 483 }
nuclear@0 484
nuclear@11 485 static Vector3 get_primary_ray_dir(int x, int y, int w, int h, float vfov_deg)
nuclear@0 486 {
nuclear@0 487 float vfov = M_PI * vfov_deg / 180.0;
nuclear@0 488 float aspect = (float)w / (float)h;
nuclear@0 489
nuclear@0 490 float ysz = 2.0;
nuclear@0 491 float xsz = aspect * ysz;
nuclear@0 492
nuclear@0 493 float px = ((float)x / (float)w) * xsz - xsz / 2.0;
nuclear@0 494 float py = 1.0 - ((float)y / (float)h) * ysz;
nuclear@0 495 float pz = 1.0 / tan(0.5 * vfov);
nuclear@0 496
nuclear@0 497 float mag = sqrt(px * px + py * py + pz * pz);
nuclear@11 498 return Vector3(px / mag, py / mag, pz / mag);
nuclear@0 499 }
nuclear@0 500
nuclear@0 501 static int round_pow2(int x)
nuclear@0 502 {
nuclear@0 503 x--;
nuclear@0 504 x = (x >> 1) | x;
nuclear@0 505 x = (x >> 2) | x;
nuclear@0 506 x = (x >> 4) | x;
nuclear@0 507 x = (x >> 8) | x;
nuclear@0 508 x = (x >> 16) | x;
nuclear@0 509 return x + 1;
nuclear@0 510 }
nuclear@0 511
nuclear@3 512 static void create_transfer_map(float mean, float sdev)
nuclear@3 513 {
nuclear@3 514 static float map[XFER_MAP_SZ];
nuclear@3 515
nuclear@3 516 if(!xfer_tex) {
nuclear@3 517 glGenTextures(1, &xfer_tex);
nuclear@3 518 glBindTexture(GL_TEXTURE_1D, xfer_tex);
nuclear@3 519 glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
nuclear@3 520 glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
nuclear@3 521 glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
nuclear@3 522 glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
nuclear@3 523 glTexImage1D(GL_TEXTURE_1D, 0, GL_LUMINANCE32F_ARB, XFER_MAP_SZ, 0, GL_LUMINANCE, GL_FLOAT, 0);
nuclear@3 524 }
nuclear@3 525
nuclear@11 526 for(int i=0; i<XFER_MAP_SZ; i++) {
nuclear@4 527 float x = (float)i / (float)(XFER_MAP_SZ - 1);
nuclear@4 528 map[i] = gaussian(x, mean, sdev) - 1.0;
nuclear@3 529 }
nuclear@3 530
nuclear@4 531 glTexSubImage1D(GL_TEXTURE_1D, 0, 0, XFER_MAP_SZ, GL_LUMINANCE, GL_FLOAT, map);
nuclear@11 532 xfertex_needs_recalc = false;
nuclear@3 533 }