progs/demos/ipers.c

   1 /*
   2  * This program is under the GNU GPL.
   3  * Use at your own risk.
   4  *
   5  * written by David Bucciarelli (tech.hmw@plus.it)
   6  *            Humanware s.r.l.
   7  */
   8
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <math.h>
  12 #include <string.h>
  13
  14 #if defined (WIN32)|| defined(_WIN32)
  15 #include <windows.h>
  16 #include <mmsystem.h>
  17 #endif
  18
  19 #include <GL/glut.h>
  20
  21 #include "readtex.h"
  22
  23 #ifdef XMESA
  24 #include "GL/xmesa.h"
  25 static int fullscreen = 1;
  26 #endif
  27
  28 static int WIDTH = 640;
  29 static int HEIGHT = 480;
  30
  31 static GLint T0;
  32 static GLint Frames;
  33
  34 #define MAX_LOD 9
  35
  36 #define TEX_SKY_WIDTH 256
  37 #define TEX_SKY_HEIGHT TEX_SKY_WIDTH
  38
  39 #ifndef M_PI
  40 #define M_PI 3.1415926535
  41 #endif
  42
  43 #define FROM_NONE   0
  44 #define FROM_DOWN   1
  45 #define FROM_UP     2
  46 #define FROM_LEFT   3
  47 #define FROM_RIGHT  4
  48 #define FROM_FRONT  5
  49 #define FROM_BACK   6
  50
  51 static int win = 0;
  52
  53 static float obs[3] = { 3.8, 0.0, 0.0 };
  54 static float dir[3];
  55 static float v = 0.0;
  56 static float alpha = -90.0;
  57 static float beta = 90.0;
  58
  59 static int fog = 1;
  60 static int bfcull = 1;
  61 static int usetex = 1;
  62 static int help = 1;
  63 static int poutline = 0;
  64 static int normext = 1;
  65 static int joyavailable = 0;
  66 static int joyactive = 0;
  67 static int LODbias = 3;
  68 static int maxdepth = MAX_LOD;
  69
  70 static unsigned int totpoly = 0;
  71
  72 static GLuint t1id, t2id;
  73 static GLuint skydlist, LODdlist[MAX_LOD], LODnumpoly[MAX_LOD];
  74
  75 static void
  76 initlight(void)
  77 {
  78    GLfloat lspec[4] = { 1.0, 1.0, 1.0, 1.0 };
  79    static GLfloat lightpos[4] = { 30, 15.0, 30.0, 1.0 };
  80
  81    glLightfv(GL_LIGHT0, GL_POSITION, lightpos);
  82    glLightfv(GL_LIGHT0, GL_SPECULAR, lspec);
  83
  84    glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, 32.0);
  85    glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, lspec);
  86 }
  87
  88 static void
  89 initdlists(void)
  90 {
  91    static int slicetable[MAX_LOD][2] = {
  92       {21, 10},
  93       {18, 9},
  94       {15, 8},
  95       {12, 7},
  96       {9, 6},
  97       {7, 5},
  98       {5, 4},
  99       {4, 3},
 100       {3, 2}
 101    };
 102    GLUquadricObj *obj;
 103    int i, xslices, yslices;
 104
 105    obj = gluNewQuadric();
 106
 107    skydlist = glGenLists(1);
 108    glNewList(skydlist, GL_COMPILE);
 109    glBindTexture(GL_TEXTURE_2D, t2id);
 110    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
 111    glColor3f(1.0f, 1.0f, 1.0f);
 112
 113    gluQuadricDrawStyle(obj, GLU_FILL);
 114    gluQuadricNormals(obj, GLU_NONE);
 115    gluQuadricTexture(obj, GL_TRUE);
 116    gluQuadricOrientation(obj, GLU_INSIDE);
 117    gluSphere(obj, 40.0f, 18, 9);
 118
 119    glEndList();
 120
 121    for (i = 0; i < MAX_LOD; i++) {
 122       LODdlist[i] = glGenLists(1);
 123       glNewList(LODdlist[i], GL_COMPILE);
 124
 125       gluQuadricDrawStyle(obj, GLU_FILL);
 126       gluQuadricNormals(obj, GLU_SMOOTH);
 127       gluQuadricTexture(obj, GL_TRUE);
 128       gluQuadricOrientation(obj, GLU_OUTSIDE);
 129       xslices = slicetable[i][0];
 130       yslices = slicetable[i][1];
 131       gluSphere(obj, 1.0f, xslices, yslices);
 132       LODnumpoly[i] = xslices * (yslices - 2) + 2 * (xslices - 1);
 133
 134       glEndList();
 135    }
 136 }
 137
 138 static void
 139 inittextures(void)
 140 {
 141    GLubyte tsky[TEX_SKY_HEIGHT][TEX_SKY_WIDTH][3];
 142    GLuint x, y;
 143    GLfloat fact;
 144    GLenum gluerr;
 145
 146    /* Brick */
 147
 148    glGenTextures(1, &t1id);
 149    glBindTexture(GL_TEXTURE_2D, t1id);
 150
 151    if (!LoadRGBMipmaps("../images/bw.rgb", 3)) {
 152       fprintf(stderr, "Error reading a texture.\n");
 153       exit(-1);
 154    }
 155
 156    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
 157    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
 158
 159    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
 160                    GL_LINEAR_MIPMAP_LINEAR);
 161    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 162
 163    /* Sky */
 164
 165    glGenTextures(1, &t2id);
 166    glBindTexture(GL_TEXTURE_2D, t2id);
 167
 168    for (y = 0; y < TEX_SKY_HEIGHT; y++)
 169       for (x = 0; x < TEX_SKY_WIDTH; x++)
 170          if (y < TEX_SKY_HEIGHT / 2) {
 171             fact = y / (GLfloat) (TEX_SKY_HEIGHT / 2);
 172             tsky[y][x][0] =
 173                (GLubyte) (255.0f * (0.1f * fact + 0.3f * (1.0f - fact)));
 174             tsky[y][x][1] =
 175                (GLubyte) (255.0f * (0.2f * fact + 1.0f * (1.0f - fact)));
 176             tsky[y][x][2] = 255;
 177          }
 178          else {
 179             tsky[y][x][0] = tsky[TEX_SKY_HEIGHT - y - 1][x][0];
 180             tsky[y][x][1] = tsky[TEX_SKY_HEIGHT - y - 1][x][1];
 181             tsky[y][x][2] = 255;
 182          }
 183
 184    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 185    if (
 186        (gluerr =
 187         gluBuild2DMipmaps(GL_TEXTURE_2D, 3, TEX_SKY_WIDTH, TEX_SKY_HEIGHT,
 188                           GL_RGB, GL_UNSIGNED_BYTE, (GLvoid *) (tsky)))) {
 189       fprintf(stderr, "GLULib%s\n", (char *) gluErrorString(gluerr));
 190       exit(-1);
 191    }
 192
 193    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
 194    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
 195
 196    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
 197                    GL_LINEAR_MIPMAP_LINEAR);
 198    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 199 }
 200
 201 static void
 202 calcposobs(void)
 203 {
 204    dir[0] = sin(alpha * M_PI / 180.0);
 205    dir[1] = cos(alpha * M_PI / 180.0) * sin(beta * M_PI / 180.0);
 206    dir[2] = cos(beta * M_PI / 180.0);
 207
 208    if (dir[0] < 1.0e-5 && dir[0] > -1.0e-5)
 209       dir[0] = 0;
 210    if (dir[1] < 1.0e-5 && dir[1] > -1.0e-5)
 211       dir[1] = 0;
 212    if (dir[2] < 1.0e-5 && dir[2] > -1.0e-5)
 213       dir[2] = 0;
 214
 215    obs[0] += v * dir[0];
 216    obs[1] += v * dir[1];
 217    obs[2] += v * dir[2];
 218 }
 219
 220 static void
 221 special(int k, int x, int y)
 222 {
 223    switch (k) {
 224    case GLUT_KEY_LEFT:
 225       alpha -= 2.0;
 226       break;
 227    case GLUT_KEY_RIGHT:
 228       alpha += 2.0;
 229       break;
 230    case GLUT_KEY_DOWN:
 231       beta -= 2.0;
 232       break;
 233    case GLUT_KEY_UP:
 234       beta += 2.0;
 235       break;
 236    }
 237 }
 238
 239 static void
 240 key(unsigned char k, int x, int y)
 241 {
 242    switch (k) {
 243    case 27:
 244       exit(0);
 245       break;
 246
 247    case 'a':
 248       v += 0.01;
 249       break;
 250    case 'z':
 251       v -= 0.01;
 252       break;
 253
 254 #ifdef XMESA
 255    case ' ':
 256       fullscreen = (!fullscreen);
 257       XMesaSetFXmode(fullscreen ? XMESA_FX_FULLSCREEN : XMESA_FX_WINDOW);
 258       break;
 259 #endif
 260
 261    case '+':
 262       LODbias--;
 263       break;
 264    case '-':
 265       LODbias++;
 266       break;
 267    case 'j':
 268       joyactive = (!joyactive);
 269       break;
 270    case 'h':
 271       help = (!help);
 272       break;
 273    case 'f':
 274       fog = (!fog);
 275       break;
 276    case 't':
 277       usetex = (!usetex);
 278       break;
 279    case 'n':
 280       normext = (!normext);
 281       break;
 282    case 'b':
 283       if (bfcull) {
 284          glDisable(GL_CULL_FACE);
 285          bfcull = 0;
 286       }
 287       else {
 288          glEnable(GL_CULL_FACE);
 289          bfcull = 1;
 290       }
 291       break;
 292    case 'p':
 293       if (poutline) {
 294          glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
 295          poutline = 0;
 296          usetex = 1;
 297       }
 298       else {
 299          glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
 300          poutline = 1;
 301          usetex = 0;
 302       }
 303       break;
 304    }
 305 }
 306
 307 static void
 308 reshape(int w, int h)
 309 {
 310    WIDTH = w;
 311    HEIGHT = h;
 312    glMatrixMode(GL_PROJECTION);
 313    glLoadIdentity();
 314    gluPerspective(90.0, w / (float) h, 0.8, 100.0);
 315    glMatrixMode(GL_MODELVIEW);
 316    glLoadIdentity();
 317    glViewport(0, 0, w, h);
 318 }
 319
 320 static void
 321 printstring(void *font, char *string)
 322 {
 323    int len, i;
 324
 325    len = (int) strlen(string);
 326    for (i = 0; i < len; i++)
 327       glutBitmapCharacter(font, string[i]);
 328 }
 329
 330 static void
 331 printhelp(void)
 332 {
 333    glEnable(GL_BLEND);
 334    glColor4f(0.5, 0.5, 0.5, 0.5);
 335    glRecti(40, 40, 600, 440);
 336    glDisable(GL_BLEND);
 337
 338    glColor3f(1.0, 0.0, 0.0);
 339    glRasterPos2i(300, 420);
 340    printstring(GLUT_BITMAP_TIMES_ROMAN_24, "Help");
 341
 342    glRasterPos2i(60, 390);
 343    printstring(GLUT_BITMAP_TIMES_ROMAN_24, "h - Toggle Help");
 344    glRasterPos2i(60, 360);
 345    printstring(GLUT_BITMAP_TIMES_ROMAN_24, "t - Toggle Textures");
 346    glRasterPos2i(60, 330);
 347    printstring(GLUT_BITMAP_TIMES_ROMAN_24, "f - Toggle Fog");
 348    glRasterPos2i(60, 300);
 349    printstring(GLUT_BITMAP_TIMES_ROMAN_24, "b - Toggle Back face culling");
 350    glRasterPos2i(60, 270);
 351    printstring(GLUT_BITMAP_TIMES_ROMAN_24, "Arrow Keys - Rotate");
 352    glRasterPos2i(60, 240);
 353    printstring(GLUT_BITMAP_TIMES_ROMAN_24, "a - Increase velocity");
 354    glRasterPos2i(60, 210);
 355    printstring(GLUT_BITMAP_TIMES_ROMAN_24, "z - Decrease velocity");
 356    glRasterPos2i(60, 180);
 357    printstring(GLUT_BITMAP_TIMES_ROMAN_24, "p - Toggle Wire frame");
 358    glRasterPos2i(60, 150);
 359    printstring(GLUT_BITMAP_TIMES_ROMAN_24,
 360                "n - Toggle GL_EXT_rescale_normal extension");
 361    glRasterPos2i(60, 120);
 362    printstring(GLUT_BITMAP_TIMES_ROMAN_24,
 363                "+/- - Increase/decrease the Object maximum LOD");
 364
 365    glRasterPos2i(60, 90);
 366    if (joyavailable)
 367       printstring(GLUT_BITMAP_TIMES_ROMAN_24,
 368                   "j - Toggle jostick control (Joystick control available)");
 369    else
 370       printstring(GLUT_BITMAP_TIMES_ROMAN_24,
 371                   "(No Joystick control available)");
 372 }
 373
 374 static void
 375 dojoy(void)
 376 {
 377 #ifdef _WIN32
 378    static UINT max[2] = { 0, 0 };
 379    static UINT min[2] = { 0xffffffff, 0xffffffff }, center[2];
 380    MMRESULT res;
 381    JOYINFO joy;
 382
 383    res = joyGetPos(JOYSTICKID1, &joy);
 384
 385    if (res == JOYERR_NOERROR) {
 386       joyavailable = 1;
 387
 388       if (max[0] < joy.wXpos)
 389          max[0] = joy.wXpos;
 390       if (min[0] > joy.wXpos)
 391          min[0] = joy.wXpos;
 392       center[0] = (max[0] + min[0]) / 2;
 393
 394       if (max[1] < joy.wYpos)
 395          max[1] = joy.wYpos;
 396       if (min[1] > joy.wYpos)
 397          min[1] = joy.wYpos;
 398       center[1] = (max[1] + min[1]) / 2;
 399
 400       if (joyactive) {
 401          if (fabs(center[0] - (float) joy.wXpos) > 0.1 * (max[0] - min[0]))
 402             alpha -=
 403                2.0 * (center[0] - (float) joy.wXpos) / (max[0] - min[0]);
 404          if (fabs(center[1] - (float) joy.wYpos) > 0.1 * (max[1] - min[1]))
 405             beta += 2.0 * (center[1] - (float) joy.wYpos) / (max[1] - min[1]);
 406
 407          if (joy.wButtons & JOY_BUTTON1)
 408             v += 0.01;
 409          if (joy.wButtons & JOY_BUTTON2)
 410             v -= 0.01;
 411       }
 412    }
 413    else
 414       joyavailable = 0;
 415 #endif
 416 }
 417
 418 static void
 419 drawipers(int depth, int from)
 420 {
 421    int lod;
 422
 423    if (depth == maxdepth)
 424       return;
 425
 426    lod = depth + LODbias;
 427    if (lod < 0)
 428       lod = 0;
 429    if (lod >= MAX_LOD)
 430       return;
 431
 432    switch (from) {
 433    case FROM_NONE:
 434       glCallList(LODdlist[lod]);
 435
 436       depth++;
 437       drawipers(depth, FROM_DOWN);
 438       drawipers(depth, FROM_UP);
 439       drawipers(depth, FROM_FRONT);
 440       drawipers(depth, FROM_BACK);
 441       drawipers(depth, FROM_LEFT);
 442       drawipers(depth, FROM_RIGHT);
 443       break;
 444    case FROM_FRONT:
 445       glPushMatrix();
 446       glTranslatef(0.0f, -1.5f, 0.0f);
 447       glScalef(0.5f, 0.5f, 0.5f);
 448
 449       glCallList(LODdlist[lod]);
 450
 451       depth++;
 452       drawipers(depth, FROM_DOWN);
 453       drawipers(depth, FROM_UP);
 454       drawipers(depth, FROM_FRONT);
 455       drawipers(depth, FROM_LEFT);
 456       drawipers(depth, FROM_RIGHT);
 457       glPopMatrix();
 458       break;
 459    case FROM_BACK:
 460       glPushMatrix();
 461       glTranslatef(0.0f, 1.5f, 0.0f);
 462       glScalef(0.5f, 0.5f, 0.5f);
 463
 464       glCallList(LODdlist[lod]);
 465
 466       depth++;
 467       drawipers(depth, FROM_DOWN);
 468       drawipers(depth, FROM_UP);
 469       drawipers(depth, FROM_BACK);
 470       drawipers(depth, FROM_LEFT);
 471       drawipers(depth, FROM_RIGHT);
 472       glPopMatrix();
 473       break;
 474    case FROM_LEFT:
 475       glPushMatrix();
 476       glTranslatef(-1.5f, 0.0f, 0.0f);
 477       glScalef(0.5f, 0.5f, 0.5f);
 478
 479       glCallList(LODdlist[lod]);
 480
 481       depth++;
 482       drawipers(depth, FROM_DOWN);
 483       drawipers(depth, FROM_UP);
 484       drawipers(depth, FROM_FRONT);
 485       drawipers(depth, FROM_BACK);
 486       drawipers(depth, FROM_LEFT);
 487       glPopMatrix();
 488       break;
 489    case FROM_RIGHT:
 490       glPushMatrix();
 491       glTranslatef(1.5f, 0.0f, 0.0f);
 492       glScalef(0.5f, 0.5f, 0.5f);
 493
 494       glCallList(LODdlist[lod]);
 495
 496       depth++;
 497       drawipers(depth, FROM_DOWN);
 498       drawipers(depth, FROM_UP);
 499       drawipers(depth, FROM_FRONT);
 500       drawipers(depth, FROM_BACK);
 501       drawipers(depth, FROM_RIGHT);
 502       glPopMatrix();
 503       break;
 504    case FROM_DOWN:
 505       glPushMatrix();
 506       glTranslatef(0.0f, 0.0f, 1.5f);
 507       glScalef(0.5f, 0.5f, 0.5f);
 508
 509       glCallList(LODdlist[lod]);
 510
 511       depth++;
 512       drawipers(depth, FROM_DOWN);
 513       drawipers(depth, FROM_FRONT);
 514       drawipers(depth, FROM_BACK);
 515       drawipers(depth, FROM_LEFT);
 516       drawipers(depth, FROM_RIGHT);
 517       glPopMatrix();
 518       break;
 519    case FROM_UP:
 520       glPushMatrix();
 521       glTranslatef(0.0f, 0.0f, -1.5f);
 522       glScalef(0.5f, 0.5f, 0.5f);
 523
 524       glCallList(LODdlist[lod]);
 525
 526       depth++;
 527       drawipers(depth, FROM_UP);
 528       drawipers(depth, FROM_FRONT);
 529       drawipers(depth, FROM_BACK);
 530       drawipers(depth, FROM_LEFT);
 531       drawipers(depth, FROM_RIGHT);
 532       glPopMatrix();
 533       break;
 534    }
 535
 536    totpoly += LODnumpoly[lod];
 537 }
 538
 539 static void
 540 draw(void)
 541 {
 542    static char frbuf[80] = "";
 543    static GLfloat alpha = 0.0f;
 544    static GLfloat beta = 0.0f;
 545    static float fr = 0.0;
 546    static double t0 = -1.;
 547    double dt, t = glutGet(GLUT_ELAPSED_TIME) / 1000.0;
 548    if (t0 < 0.0)
 549       t0 = t;
 550    dt = t - t0;
 551    t0 = t;
 552
 553    dojoy();
 554
 555    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 556
 557    if (usetex)
 558       glEnable(GL_TEXTURE_2D);
 559    else
 560       glDisable(GL_TEXTURE_2D);
 561
 562    if (fog)
 563       glEnable(GL_FOG);
 564    else
 565       glDisable(GL_FOG);
 566
 567    glPushMatrix();
 568    calcposobs();
 569    gluLookAt(obs[0], obs[1], obs[2],
 570              obs[0] + dir[0], obs[1] + dir[1], obs[2] + dir[2],
 571              0.0, 0.0, 1.0);
 572
 573    /* Scene */
 574    glEnable(GL_DEPTH_TEST);
 575
 576    glShadeModel(GL_SMOOTH);
 577    glBindTexture(GL_TEXTURE_2D, t1id);
 578    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
 579    glColor3f(1.0f, 1.0f, 1.0f);
 580    glEnable(GL_LIGHT0);
 581    glEnable(GL_LIGHTING);
 582
 583    if (normext)
 584       glEnable(GL_RESCALE_NORMAL_EXT);
 585    else
 586       glEnable(GL_NORMALIZE);
 587
 588    glPushMatrix();
 589    glRotatef(alpha, 0.0f, 0.0f, 1.0f);
 590    glRotatef(beta, 1.0f, 0.0f, 0.0f);
 591    totpoly = 0;
 592    drawipers(0, FROM_NONE);
 593    glPopMatrix();
 594
 595    alpha += 4.f * dt;
 596    beta += 2.4f * dt;
 597
 598    glDisable(GL_LIGHTING);
 599    glDisable(GL_LIGHT0);
 600    glShadeModel(GL_FLAT);
 601
 602    if (normext)
 603       glDisable(GL_RESCALE_NORMAL_EXT);
 604    else
 605       glDisable(GL_NORMALIZE);
 606
 607    glCallList(skydlist);
 608
 609    glPopMatrix();
 610
 611    /* Help Screen */
 612
 613    sprintf(frbuf,
 614            "Frame rate: %0.2f   LOD: %d   Tot. poly.: %d   Poly/sec: %.1f",
 615            fr, LODbias, totpoly, totpoly * fr);
 616
 617    glDisable(GL_TEXTURE_2D);
 618    glDisable(GL_FOG);
 619    glShadeModel(GL_FLAT);
 620    glDisable(GL_DEPTH_TEST);
 621
 622    glMatrixMode(GL_PROJECTION);
 623    glPushMatrix();
 624    glLoadIdentity();
 625    glOrtho(-0.5, 639.5, -0.5, 479.5, -1.0, 1.0);
 626
 627    glMatrixMode(GL_MODELVIEW);
 628    glLoadIdentity();
 629
 630    glColor3f(1.0, 0.0, 0.0);
 631    glRasterPos2i(10, 10);
 632    printstring(GLUT_BITMAP_HELVETICA_18, frbuf);
 633    glRasterPos2i(350, 470);
 634    printstring(GLUT_BITMAP_HELVETICA_10,
 635                "IperS V1.0 Written by David Bucciarelli (tech.hmw@plus.it)");
 636
 637    if (help)
 638       printhelp();
 639
 640    glMatrixMode(GL_PROJECTION);
 641    glPopMatrix();
 642    glMatrixMode(GL_MODELVIEW);
 643
 644    glutSwapBuffers();
 645
 646    Frames++;
 647    {
 648       GLint t = glutGet(GLUT_ELAPSED_TIME);
 649       if (t - T0 >= 2000) {
 650          GLfloat seconds = (t - T0) / 1000.0;
 651          fr = Frames / seconds;
 652          T0 = t;
 653          Frames = 0;
 654       }
 655    }
 656 }
 657
 658 int
 659 main(int ac, char **av)
 660 {
 661    float fogcolor[4] = { 0.7, 0.7, 0.7, 1.0 };
 662
 663    fprintf(stderr,
 664            "IperS V1.0\nWritten by David Bucciarelli (tech.hmw@plus.it)\n");
 665
 666    glutInitWindowPosition(0, 0);
 667    glutInitWindowSize(WIDTH, HEIGHT);
 668    glutInit(&ac, av);
 669
 670    glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE);
 671
 672    if (!(win = glutCreateWindow("IperS"))) {
 673       fprintf(stderr, "Error, couldn't open window\n");
 674       exit(-1);
 675    }
 676
 677    reshape(WIDTH, HEIGHT);
 678
 679    glShadeModel(GL_SMOOTH);
 680    glEnable(GL_DEPTH_TEST);
 681    glEnable(GL_CULL_FACE);
 682    glEnable(GL_TEXTURE_2D);
 683
 684    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 685
 686    glEnable(GL_FOG);
 687    glFogi(GL_FOG_MODE, GL_EXP2);
 688    glFogfv(GL_FOG_COLOR, fogcolor);
 689
 690    glFogf(GL_FOG_DENSITY, 0.006);
 691
 692    glHint(GL_FOG_HINT, GL_NICEST);
 693
 694    inittextures();
 695    initdlists();
 696    initlight();
 697
 698    glClearColor(fogcolor[0], fogcolor[1], fogcolor[2], fogcolor[3]);
 699    glClear(GL_COLOR_BUFFER_BIT);
 700
 701    calcposobs();
 702
 703    glutReshapeFunc(reshape);
 704    glutDisplayFunc(draw);
 705    glutKeyboardFunc(key);
 706    glutSpecialFunc(special);
 707    glutIdleFunc(draw);
 708
 709    glutMainLoop();
 710
 711    return 0;
 712 }