progs/tests/fbotexture.c

   1 /*
   2  * Test GL_EXT_framebuffer_object render-to-texture
   3  *
   4  * Draw a teapot into a texture image with stenciling.
   5  * Then draw a textured quad using that texture.
   6  *
   7  * Brian Paul
   8  * 18 Apr 2005
   9  */
  10
  11
  12 #define GL_GLEXT_PROTOTYPES
  13 #include <GL/glut.h>
  14 #include <assert.h>
  15 #include <stdio.h>
  16 #include <stdlib.h>
  17 #include <string.h>
  18 #include <math.h>
  19
  20 /* For debug */
  21 #define DEPTH 1
  22 #define STENCIL 1
  23 #define DRAW 1
  24
  25
  26 static int Win = 0;
  27 static int Width = 400, Height = 400;
  28
  29 static GLenum TexTarget = GL_TEXTURE_2D; /*GL_TEXTURE_RECTANGLE_ARB;*/
  30 static int TexWidth = 512, TexHeight = 512;
  31 /*static int TexWidth = 600, TexHeight = 600;*/
  32
  33 static GLuint MyFB;
  34 static GLuint TexObj;
  35 static GLuint DepthRB = 0, StencilRB = 0;
  36 static GLboolean Anim = GL_FALSE;
  37 static GLfloat Rot = 0.0;
  38 static GLboolean UsePackedDepthStencil = GL_FALSE;
  39 static GLboolean UsePackedDepthStencilBoth = GL_FALSE;
  40 static GLboolean Use_ARB_fbo = GL_FALSE;
  41 static GLuint TextureLevel = 0;  /* which texture level to render to */
  42 static GLenum TexIntFormat = GL_RGB; /* either GL_RGB or GL_RGBA */
  43 static GLboolean Cull = GL_FALSE;
  44 static GLboolean Wireframe = GL_FALSE;
  45
  46
  47 static void
  48 CheckError(int line)
  49 {
  50    GLenum err = glGetError();
  51    if (err) {
  52       printf("GL Error 0x%x at line %d\n", (int) err, line);
  53    }
  54 }
  55
  56
  57 static void
  58 Idle(void)
  59 {
  60    Rot = glutGet(GLUT_ELAPSED_TIME) * 0.1;
  61    glutPostRedisplay();
  62 }
  63
  64
  65 static void
  66 RenderTexture(void)
  67 {
  68    GLenum status;
  69
  70    glMatrixMode(GL_PROJECTION);
  71    glLoadIdentity();
  72    glOrtho(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0);
  73    glMatrixMode(GL_MODELVIEW);
  74    glLoadIdentity();
  75    glTranslatef(0.0, 0.0, -15.0);
  76
  77    /* draw to texture image */
  78    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, MyFB);
  79
  80    status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
  81    if (status != GL_FRAMEBUFFER_COMPLETE_EXT) {
  82       printf("Framebuffer incomplete!!!\n");
  83    }
  84
  85    glViewport(0, 0, TexWidth, TexHeight);
  86
  87    glClearColor(0.5, 0.5, 1.0, 0.0);
  88    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
  89    CheckError(__LINE__);
  90
  91 #if DEPTH
  92    glEnable(GL_DEPTH_TEST);
  93 #endif
  94
  95 #if STENCIL
  96    glEnable(GL_STENCIL_TEST);
  97    glStencilFunc(GL_NEVER, 1, ~0);
  98    glStencilOp(GL_REPLACE, GL_KEEP, GL_REPLACE);
  99 #endif
 100
 101    CheckError(__LINE__);
 102
 103 #if DEPTH || STENCIL
 104    /* draw diamond-shaped stencil pattern */
 105    glColor3f(0, 1, 0);
 106    glBegin(GL_POLYGON);
 107    glVertex2f(-0.2,  0.0);
 108    glVertex2f( 0.0, -0.2);
 109    glVertex2f( 0.2,  0.0);
 110    glVertex2f( 0.0,  0.2);
 111    glEnd();
 112 #endif
 113
 114    /* draw teapot where stencil != 1 */
 115 #if STENCIL
 116    glStencilFunc(GL_NOTEQUAL, 1, ~0);
 117    glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
 118 #endif
 119
 120    CheckError(__LINE__);
 121
 122    if (Wireframe) {
 123       glPolygonMode(GL_FRONT, GL_LINE);
 124    }
 125    else {
 126       glPolygonMode(GL_FRONT, GL_FILL);
 127    }
 128
 129    if (Cull) {
 130       /* cull back */
 131       glCullFace(GL_BACK);
 132       glEnable(GL_CULL_FACE);
 133    }
 134    else {
 135       glDisable(GL_CULL_FACE);
 136    }
 137
 138 #if 0
 139    glBegin(GL_POLYGON);
 140    glColor3f(1, 0, 0);
 141    glVertex2f(-1, -1);
 142    glColor3f(0, 1, 0);
 143    glVertex2f(1, -1);
 144    glColor3f(0, 0, 1);
 145    glVertex2f(0, 1);
 146    glEnd();
 147 #else
 148    glEnable(GL_LIGHTING);
 149    glEnable(GL_LIGHT0);
 150    glPushMatrix();
 151    glRotatef(0.5 * Rot, 1.0, 0.0, 0.0);
 152    glFrontFace(GL_CW); /* Teapot patches backward */
 153    glutSolidTeapot(0.5);
 154    glFrontFace(GL_CCW);
 155    glPopMatrix();
 156    glDisable(GL_LIGHTING);
 157    /*
 158    PrintStencilHistogram(TexWidth, TexHeight);
 159    */
 160 #endif
 161
 162    glDisable(GL_DEPTH_TEST);
 163    glDisable(GL_STENCIL_TEST);
 164    glDisable(GL_CULL_FACE);
 165    glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
 166
 167 #if DRAW
 168    /* Bind normal framebuffer */
 169    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
 170 #endif
 171
 172    CheckError(__LINE__);
 173 }
 174
 175
 176
 177 static void
 178 Display(void)
 179 {
 180    float ar = (float) Width / (float) Height;
 181
 182    RenderTexture();
 183
 184    /* draw textured quad in the window */
 185 #if DRAW
 186    glMatrixMode(GL_PROJECTION);
 187    glLoadIdentity();
 188    glFrustum(-ar, ar, -1.0, 1.0, 5.0, 25.0);
 189    glMatrixMode(GL_MODELVIEW);
 190    glLoadIdentity();
 191    glTranslatef(0.0, 0.0, -7.0);
 192
 193    glViewport(0, 0, Width, Height);
 194
 195    glClearColor(0.25, 0.25, 0.25, 0);
 196    glClear(GL_COLOR_BUFFER_BIT);
 197
 198    glPushMatrix();
 199    glRotatef(Rot, 0, 1, 0);
 200    glEnable(TexTarget);
 201    glBindTexture(TexTarget, TexObj);
 202    glBegin(GL_POLYGON);
 203    glColor3f(0.25, 0.25, 0.25);
 204    if (TexTarget == GL_TEXTURE_2D) {
 205       glTexCoord2f(0, 0);
 206       glVertex2f(-1, -1);
 207       glTexCoord2f(1, 0);
 208       glVertex2f(1, -1);
 209       glColor3f(1.0, 1.0, 1.0);
 210       glTexCoord2f(1, 1);
 211       glVertex2f(1, 1);
 212       glTexCoord2f(0, 1);
 213       glVertex2f(-1, 1);
 214    }
 215    else {
 216       assert(TexTarget == GL_TEXTURE_RECTANGLE_ARB);
 217       glTexCoord2f(0, 0);
 218       glVertex2f(-1, -1);
 219       glTexCoord2f(TexWidth, 0);
 220       glVertex2f(1, -1);
 221       glColor3f(1.0, 1.0, 1.0);
 222       glTexCoord2f(TexWidth, TexHeight);
 223       glVertex2f(1, 1);
 224       glTexCoord2f(0, TexHeight);
 225       glVertex2f(-1, 1);
 226    }
 227    glEnd();
 228    glPopMatrix();
 229    glDisable(TexTarget);
 230 #endif
 231
 232    glutSwapBuffers();
 233    CheckError(__LINE__);
 234 }
 235
 236
 237 static void
 238 Reshape(int width, int height)
 239 {
 240    glViewport(0, 0, width, height);
 241    Width = width;
 242    Height = height;
 243 }
 244
 245
 246 static void
 247 CleanUp(void)
 248 {
 249 #if DEPTH
 250    glDeleteRenderbuffersEXT(1, &DepthRB);
 251 #endif
 252 #if STENCIL
 253    glDeleteRenderbuffersEXT(1, &StencilRB);
 254 #endif
 255    glDeleteFramebuffersEXT(1, &MyFB);
 256
 257    glDeleteTextures(1, &TexObj);
 258
 259    glutDestroyWindow(Win);
 260
 261    exit(0);
 262 }
 263
 264
 265 static void
 266 Key(unsigned char key, int x, int y)
 267 {
 268    (void) x;
 269    (void) y;
 270    switch (key) {
 271    case 'a':
 272       Anim = !Anim;
 273       if (Anim)
 274          glutIdleFunc(Idle);
 275       else
 276          glutIdleFunc(NULL);
 277       break;
 278    case 'c':
 279       Cull = !Cull;
 280       break;
 281    case 'w':
 282       Wireframe = !Wireframe;
 283       break;
 284    case 's':
 285       Rot += 2.0;
 286       break;
 287    case 'S':
 288       Rot -= 2.0;
 289       break;
 290    case 27:
 291       CleanUp();
 292       break;
 293    }
 294    glutPostRedisplay();
 295 }
 296
 297
 298 /**
 299  * Attach depth and stencil renderbuffer(s) to the given framebuffer object.
 300  * \param tryDepthStencil  if true, try to use a combined depth+stencil buffer
 301  * \param bindDepthStencil  if true, and tryDepthStencil is true, bind with
 302  *                          the GL_DEPTH_STENCIL_ATTACHMENT target.
 303  * \return GL_TRUE for success, GL_FALSE for failure
 304  */
 305 static GLboolean
 306 AttachDepthAndStencilBuffers(GLuint fbo,
 307                              GLsizei width, GLsizei height,
 308                              GLboolean tryDepthStencil,
 309                              GLboolean bindDepthStencil,
 310                              GLuint *depthRbOut, GLuint *stencilRbOut)
 311 {
 312    GLenum status;
 313
 314    *depthRbOut = *stencilRbOut = 0;
 315
 316    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fbo);
 317
 318    if (tryDepthStencil) {
 319       GLuint rb;
 320
 321       glGenRenderbuffersEXT(1, &rb);
 322       glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, rb);
 323       glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT,
 324                                GL_DEPTH24_STENCIL8_EXT,
 325                                width, height);
 326       if (glGetError())
 327          return GL_FALSE;
 328
 329       if (bindDepthStencil) {
 330          /* attach to both depth and stencil at once */
 331          glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT,
 332                                       GL_DEPTH_STENCIL_ATTACHMENT,
 333                                       GL_RENDERBUFFER_EXT, rb);
 334          if (glGetError())
 335             return GL_FALSE;
 336       }
 337       else {
 338          /* attach to depth attachment point */
 339          glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT,
 340                                       GL_DEPTH_ATTACHMENT_EXT,
 341                                       GL_RENDERBUFFER_EXT, rb);
 342          if (glGetError())
 343             return GL_FALSE;
 344
 345          /* and attach to stencil attachment point */
 346          glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT,
 347                                       GL_STENCIL_ATTACHMENT_EXT,
 348                                       GL_RENDERBUFFER_EXT, rb);
 349          if (glGetError())
 350             return GL_FALSE;
 351       }
 352
 353       status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
 354       if (status != GL_FRAMEBUFFER_COMPLETE_EXT)
 355          return GL_FALSE;
 356
 357       *depthRbOut = *stencilRbOut = rb;
 358       return GL_TRUE;
 359    }
 360
 361    /* just depth renderbuffer */
 362    {
 363       GLuint rb;
 364
 365       glGenRenderbuffersEXT(1, &rb);
 366       glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, rb);
 367       glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT,
 368                                GL_DEPTH_COMPONENT,
 369                                width, height);
 370       if (glGetError())
 371          return GL_FALSE;
 372
 373       /* attach to depth attachment point */
 374       glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT,
 375                                    GL_DEPTH_ATTACHMENT_EXT,
 376                                    GL_RENDERBUFFER_EXT, rb);
 377       if (glGetError())
 378          return GL_FALSE;
 379
 380       status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
 381       if (status != GL_FRAMEBUFFER_COMPLETE_EXT)
 382          return GL_FALSE;
 383
 384       *depthRbOut = rb;
 385    }
 386
 387    /* just stencil renderbuffer */
 388    {
 389       GLuint rb;
 390
 391       glGenRenderbuffersEXT(1, &rb);
 392       glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, rb);
 393       glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT,
 394                                GL_STENCIL_INDEX,
 395                                width, height);
 396       if (glGetError())
 397          return GL_FALSE;
 398
 399       /* attach to depth attachment point */
 400       glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT,
 401                                    GL_STENCIL_ATTACHMENT_EXT,
 402                                    GL_RENDERBUFFER_EXT, rb);
 403       if (glGetError())
 404          return GL_FALSE;
 405
 406       status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
 407       if (status != GL_FRAMEBUFFER_COMPLETE_EXT)
 408          return GL_FALSE;
 409
 410       *stencilRbOut = rb;
 411    }
 412
 413    return GL_TRUE;
 414 }
 415
 416
 417 static void
 418 ParseArgs(int argc, char *argv[])
 419 {
 420    GLint i;
 421    for (i = 1; i < argc; i++) {
 422       if (strcmp(argv[i], "-ds") == 0) {
 423          if (!glutExtensionSupported("GL_EXT_packed_depth_stencil")) {
 424             printf("GL_EXT_packed_depth_stencil not found!\n");
 425             exit(0);
 426          }
 427          UsePackedDepthStencil = GL_TRUE;
 428          printf("Using GL_EXT_packed_depth_stencil\n");
 429       }
 430       else if (strcmp(argv[i], "-ds2") == 0) {
 431          if (!glutExtensionSupported("GL_EXT_packed_depth_stencil")) {
 432             printf("GL_EXT_packed_depth_stencil not found!\n");
 433             exit(0);
 434          }
 435          if (!glutExtensionSupported("GL_ARB_framebuffer_object")) {
 436             printf("GL_ARB_framebuffer_object not found!\n");
 437             exit(0);
 438          }
 439          UsePackedDepthStencilBoth = GL_TRUE;
 440          printf("Using GL_EXT_packed_depth_stencil and GL_DEPTH_STENCIL attachment point\n");
 441       }
 442       else if (strcmp(argv[i], "-arb") == 0) {
 443          if (!glutExtensionSupported("GL_ARB_framebuffer_object")) {
 444             printf("Sorry, GL_ARB_framebuffer object not supported!\n");
 445          }
 446          else {
 447             Use_ARB_fbo = GL_TRUE;
 448          }
 449       }
 450       else {
 451          printf("Unknown option: %s\n", argv[i]);
 452       }
 453    }
 454 }
 455
 456
 457 /*
 458  * Make FBO to render into given texture.
 459  */
 460 static GLuint
 461 MakeFBO_RenderTexture(GLuint TexObj)
 462 {
 463    GLuint fb;
 464    GLint sizeFudge = 0;
 465
 466    glGenFramebuffersEXT(1, &fb);
 467    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fb);
 468    /* Render color to texture */
 469    glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
 470                              TexTarget, TexObj, TextureLevel);
 471
 472    if (Use_ARB_fbo) {
 473       /* use a smaller depth buffer to see what happens */
 474       sizeFudge = 90;
 475    }
 476
 477    /* Setup depth and stencil buffers */
 478    {
 479       GLboolean b;
 480       b = AttachDepthAndStencilBuffers(fb,
 481                                        TexWidth - sizeFudge,
 482                                        TexHeight - sizeFudge,
 483                                        UsePackedDepthStencil,
 484                                        UsePackedDepthStencilBoth,
 485                                        &DepthRB, &StencilRB);
 486       if (!b) {
 487          /* try !UsePackedDepthStencil */
 488          b = AttachDepthAndStencilBuffers(fb,
 489                                           TexWidth - sizeFudge,
 490                                           TexHeight - sizeFudge,
 491                                           !UsePackedDepthStencil,
 492                                           UsePackedDepthStencilBoth,
 493                                           &DepthRB, &StencilRB);
 494       }
 495       if (!b) {
 496          printf("Unable to create/attach depth and stencil renderbuffers "
 497                 " to FBO!\n");
 498          exit(1);
 499       }
 500    }
 501
 502    /* queries */
 503    {
 504       GLint bits, w, h;
 505
 506       glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, DepthRB);
 507       glGetRenderbufferParameterivEXT(GL_RENDERBUFFER_EXT,
 508                                       GL_RENDERBUFFER_WIDTH_EXT, &w);
 509       glGetRenderbufferParameterivEXT(GL_RENDERBUFFER_EXT,
 510                                       GL_RENDERBUFFER_HEIGHT_EXT, &h);
 511       printf("Color/Texture size: %d x %d\n", TexWidth, TexHeight);
 512       printf("Depth buffer size: %d x %d\n", w, h);
 513
 514       glGetRenderbufferParameterivEXT(GL_RENDERBUFFER_EXT,
 515                                       GL_RENDERBUFFER_DEPTH_SIZE_EXT, &bits);
 516       printf("Depth renderbuffer size = %d bits\n", bits);
 517
 518       glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, StencilRB);
 519       glGetRenderbufferParameterivEXT(GL_RENDERBUFFER_EXT,
 520                                       GL_RENDERBUFFER_STENCIL_SIZE_EXT, &bits);
 521       printf("Stencil renderbuffer size = %d bits\n", bits);
 522    }
 523
 524    /* bind the regular framebuffer */
 525    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
 526
 527    return fb;
 528 }
 529
 530
 531 static void
 532 Init(void)
 533 {
 534    if (!glutExtensionSupported("GL_EXT_framebuffer_object")) {
 535       printf("GL_EXT_framebuffer_object not found!\n");
 536       exit(0);
 537    }
 538
 539    printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
 540
 541    /* lighting */
 542    {
 543       static const GLfloat mat[4] = { 1.0, 0.5, 0.5, 1.0 };
 544       glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, mat);
 545    }
 546
 547    /*
 548     * Make texture object/image (we'll render into this texture)
 549     */
 550    {
 551       glGenTextures(1, &TexObj);
 552       glBindTexture(TexTarget, TexObj);
 553
 554       /* make two image levels */
 555       glTexImage2D(TexTarget, 0, TexIntFormat, TexWidth, TexHeight, 0,
 556                    GL_RGBA, GL_UNSIGNED_BYTE, NULL);
 557       glTexImage2D(TexTarget, 1, TexIntFormat, TexWidth/2, TexHeight/2, 0,
 558                    GL_RGBA, GL_UNSIGNED_BYTE, NULL);
 559       TexWidth = TexWidth >> TextureLevel;
 560       TexHeight = TexHeight >> TextureLevel;
 561
 562       glTexParameteri(TexTarget, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 563       glTexParameteri(TexTarget, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 564       glTexParameteri(TexTarget, GL_TEXTURE_BASE_LEVEL, TextureLevel);
 565       glTexParameteri(TexTarget, GL_TEXTURE_MAX_LEVEL, TextureLevel);
 566       glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
 567    }
 568
 569    MyFB = MakeFBO_RenderTexture(TexObj);
 570 }
 571
 572
 573 static void
 574 Usage(void)
 575 {
 576    printf("Usage:\n");
 577    printf("  -ds  Use combined depth/stencil renderbuffer\n");
 578    printf("  -arb Try GL_ARB_framebuffer_object's mismatched buffer sizes\n");
 579    printf("  -ds2 Tye GL_ARB_framebuffer_object's GL_DEPTH_STENCIL_ATTACHMENT\n");
 580    printf("Keys:\n");
 581    printf("  a    Toggle animation\n");
 582    printf("  s/s  Step/rotate\n");
 583    printf("  c    Toggle back-face culling\n");
 584    printf("  w    Toggle wireframe mode (front-face only)\n");
 585    printf("  Esc  Exit\n");
 586 }
 587
 588
 589 int
 590 main(int argc, char *argv[])
 591 {
 592    glutInit(&argc, argv);
 593    glutInitWindowPosition(0, 0);
 594    glutInitWindowSize(Width, Height);
 595    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);
 596    Win = glutCreateWindow(argv[0]);
 597    glutReshapeFunc(Reshape);
 598    glutKeyboardFunc(Key);
 599    glutDisplayFunc(Display);
 600    if (Anim)
 601       glutIdleFunc(Idle);
 602
 603    ParseArgs(argc, argv);
 604    Init();
 605    Usage();
 606
 607    glutMainLoop();
 608    return 0;
 609 }