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 Width = 400, Height = 400;
  27
  28 static GLenum TexTarget = GL_TEXTURE_2D; /*GL_TEXTURE_RECTANGLE_ARB;*/
  29 static int TexWidth = 512, TexHeight = 512;
  30 /*static int TexWidth = 600, TexHeight = 600;*/
  31
  32 static GLuint MyFB;
  33 static GLuint TexObj;
  34 static GLuint DepthRB, StencilRB;
  35 static GLboolean Anim = GL_FALSE;
  36 static GLfloat Rot = 0.0;
  37 static GLboolean UsePackedDepthStencil = GL_FALSE;
  38 static GLuint TextureLevel = 1;  /* which texture level to render to */
  39 static GLenum TexIntFormat = GL_RGB; /* either GL_RGB or GL_RGBA */
  40
  41
  42 static void
  43 CheckError(int line)
  44 {
  45    GLenum err = glGetError();
  46    if (err) {
  47       printf("GL Error 0x%x at line %d\n", (int) err, line);
  48    }
  49 }
  50
  51
  52 static void
  53 Idle(void)
  54 {
  55    Rot = glutGet(GLUT_ELAPSED_TIME) * 0.1;
  56    glutPostRedisplay();
  57 }
  58
  59
  60 static void
  61 RenderTexture(void)
  62 {
  63    GLenum status;
  64
  65    glMatrixMode(GL_PROJECTION);
  66    glLoadIdentity();
  67    glOrtho(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0);
  68    glMatrixMode(GL_MODELVIEW);
  69    glLoadIdentity();
  70    glTranslatef(0.0, 0.0, -15.0);
  71
  72    /* draw to texture image */
  73    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, MyFB);
  74
  75    status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
  76    if (status != GL_FRAMEBUFFER_COMPLETE_EXT) {
  77       printf("Framebuffer incomplete!!!\n");
  78    }
  79
  80    glViewport(0, 0, TexWidth, TexHeight);
  81
  82    glClearColor(0.5, 0.5, 1.0, 0.0);
  83    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
  84    CheckError(__LINE__);
  85
  86 #if DEPTH
  87    glEnable(GL_DEPTH_TEST);
  88 #endif
  89
  90 #if STENCIL
  91    glEnable(GL_STENCIL_TEST);
  92    glStencilFunc(GL_NEVER, 1, ~0);
  93    glStencilOp(GL_REPLACE, GL_KEEP, GL_REPLACE);
  94 #endif
  95
  96    CheckError(__LINE__);
  97
  98 #if DEPTH || STENCIL
  99    /* draw diamond-shaped stencil pattern */
 100    glColor3f(0, 1, 0);
 101    glBegin(GL_POLYGON);
 102    glVertex2f(-0.2,  0.0);
 103    glVertex2f( 0.0, -0.2);
 104    glVertex2f( 0.2,  0.0);
 105    glVertex2f( 0.0,  0.2);
 106    glEnd();
 107 #endif
 108
 109    /* draw teapot where stencil != 1 */
 110 #if STENCIL
 111    glStencilFunc(GL_NOTEQUAL, 1, ~0);
 112    glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
 113 #endif
 114
 115    CheckError(__LINE__);
 116
 117 #if 0
 118    glBegin(GL_POLYGON);
 119    glColor3f(1, 0, 0);
 120    glVertex2f(-1, -1);
 121    glColor3f(0, 1, 0);
 122    glVertex2f(1, -1);
 123    glColor3f(0, 0, 1);
 124    glVertex2f(0, 1);
 125    glEnd();
 126 #else
 127    glEnable(GL_LIGHTING);
 128    glEnable(GL_LIGHT0);
 129    glPushMatrix();
 130    glRotatef(0.5 * Rot, 1.0, 0.0, 0.0);
 131    glutSolidTeapot(0.5);
 132    glPopMatrix();
 133    glDisable(GL_LIGHTING);
 134    /*
 135    PrintStencilHistogram(TexWidth, TexHeight);
 136    */
 137 #endif
 138
 139    glDisable(GL_DEPTH_TEST);
 140    glDisable(GL_STENCIL_TEST);
 141
 142 #if DRAW
 143    /* Bind normal framebuffer */
 144    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
 145 #endif
 146
 147    CheckError(__LINE__);
 148 }
 149
 150
 151
 152 static void
 153 Display(void)
 154 {
 155    float ar = (float) Width / (float) Height;
 156
 157    RenderTexture();
 158
 159    /* draw textured quad in the window */
 160 #if DRAW
 161    glMatrixMode(GL_PROJECTION);
 162    glLoadIdentity();
 163    glFrustum(-ar, ar, -1.0, 1.0, 5.0, 25.0);
 164    glMatrixMode(GL_MODELVIEW);
 165    glLoadIdentity();
 166    glTranslatef(0.0, 0.0, -7.0);
 167
 168    glViewport(0, 0, Width, Height);
 169
 170    glClearColor(0.25, 0.25, 0.25, 0);
 171    glClear(GL_COLOR_BUFFER_BIT);
 172
 173    glPushMatrix();
 174    glRotatef(Rot, 0, 1, 0);
 175    glEnable(TexTarget);
 176    glBindTexture(TexTarget, TexObj);
 177    glBegin(GL_POLYGON);
 178    glColor3f(0.25, 0.25, 0.25);
 179    if (TexTarget == GL_TEXTURE_2D) {
 180       glTexCoord2f(0, 0);
 181       glVertex2f(-1, -1);
 182       glTexCoord2f(1, 0);
 183       glVertex2f(1, -1);
 184       glColor3f(1.0, 1.0, 1.0);
 185       glTexCoord2f(1, 1);
 186       glVertex2f(1, 1);
 187       glTexCoord2f(0, 1);
 188       glVertex2f(-1, 1);
 189    }
 190    else {
 191       assert(TexTarget == GL_TEXTURE_RECTANGLE_ARB);
 192       glTexCoord2f(0, 0);
 193       glVertex2f(-1, -1);
 194       glTexCoord2f(TexWidth, 0);
 195       glVertex2f(1, -1);
 196       glColor3f(1.0, 1.0, 1.0);
 197       glTexCoord2f(TexWidth, TexHeight);
 198       glVertex2f(1, 1);
 199       glTexCoord2f(0, TexHeight);
 200       glVertex2f(-1, 1);
 201    }
 202    glEnd();
 203    glPopMatrix();
 204    glDisable(TexTarget);
 205 #endif
 206
 207    glutSwapBuffers();
 208    CheckError(__LINE__);
 209 }
 210
 211
 212 static void
 213 Reshape(int width, int height)
 214 {
 215    glViewport(0, 0, width, height);
 216    Width = width;
 217    Height = height;
 218 }
 219
 220
 221 static void
 222 CleanUp(void)
 223 {
 224 #if DEPTH
 225    glDeleteRenderbuffersEXT(1, &DepthRB);
 226 #endif
 227 #if STENCIL
 228    if (!UsePackedDepthStencil)
 229       glDeleteRenderbuffersEXT(1, &StencilRB);
 230 #endif
 231    glDeleteFramebuffersEXT(1, &MyFB);
 232
 233    glDeleteTextures(1, &TexObj);
 234
 235    exit(0);
 236 }
 237
 238
 239 static void
 240 Key(unsigned char key, int x, int y)
 241 {
 242    (void) x;
 243    (void) y;
 244    switch (key) {
 245       case 'a':
 246          Anim = !Anim;
 247          if (Anim)
 248             glutIdleFunc(Idle);
 249          else
 250             glutIdleFunc(NULL);
 251          break;
 252       case 's':
 253          Rot += 2.0;
 254          break;
 255       case 27:
 256          CleanUp();
 257          break;
 258    }
 259    glutPostRedisplay();
 260 }
 261
 262
 263 static void
 264 Init(int argc, char *argv[])
 265 {
 266    static const GLfloat mat[4] = { 1.0, 0.5, 0.5, 1.0 };
 267    GLint i;
 268
 269    if (!glutExtensionSupported("GL_EXT_framebuffer_object")) {
 270       printf("GL_EXT_framebuffer_object not found!\n");
 271       exit(0);
 272    }
 273
 274    if (argc > 1 && strcmp(argv[1], "-ds") == 0) {
 275       if (!glutExtensionSupported("GL_EXT_packed_depth_stencil")) {
 276          printf("GL_EXT_packed_depth_stencil not found!\n");
 277          exit(0);
 278       }
 279       UsePackedDepthStencil = GL_TRUE;
 280       printf("Using GL_EXT_packed_depth_stencil\n");
 281    }
 282
 283    printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
 284
 285    /* gen framebuffer id, delete it, do some assertions, just for testing */
 286    glGenFramebuffersEXT(1, &MyFB);
 287    assert(MyFB);
 288    assert(!glIsFramebufferEXT(MyFB));
 289    glDeleteFramebuffersEXT(1, &MyFB);
 290    assert(!glIsFramebufferEXT(MyFB));
 291    /* Note, continue to use MyFB below */
 292
 293    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, MyFB);
 294    assert(glIsFramebufferEXT(MyFB));
 295    glGetIntegerv(GL_FRAMEBUFFER_BINDING_EXT, &i);
 296    assert(i == MyFB);
 297
 298    /* Make texture object/image */
 299    glGenTextures(1, &TexObj);
 300    glBindTexture(TexTarget, TexObj);
 301    /* make two image levels */
 302    glTexImage2D(TexTarget, 0, TexIntFormat, TexWidth, TexHeight, 0,
 303                 GL_RGBA, GL_UNSIGNED_BYTE, NULL);
 304    glTexImage2D(TexTarget, 1, TexIntFormat, TexWidth/2, TexHeight/2, 0,
 305                 GL_RGBA, GL_UNSIGNED_BYTE, NULL);
 306    TexWidth = TexWidth >> TextureLevel;
 307    TexHeight = TexHeight >> TextureLevel;
 308
 309    glTexParameteri(TexTarget, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 310    glTexParameteri(TexTarget, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 311    glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
 312    glTexParameteri(TexTarget, GL_TEXTURE_BASE_LEVEL, TextureLevel);
 313    glTexParameteri(TexTarget, GL_TEXTURE_MAX_LEVEL, TextureLevel);
 314
 315    CheckError(__LINE__);
 316
 317    /* Render color to texture */
 318    glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
 319                              TexTarget, TexObj, TextureLevel);
 320
 321
 322 #if DEPTH
 323    /* make depth renderbuffer */
 324    glGenRenderbuffersEXT(1, &DepthRB);
 325    assert(DepthRB);
 326    assert(!glIsRenderbufferEXT(DepthRB));
 327    glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, DepthRB);
 328    assert(glIsRenderbufferEXT(DepthRB));
 329    if (UsePackedDepthStencil)
 330       glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_STENCIL_EXT,
 331                                TexWidth, TexHeight);
 332    else
 333       glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT,
 334                                TexWidth, TexHeight);
 335    CheckError(__LINE__);
 336    glGetRenderbufferParameterivEXT(GL_RENDERBUFFER_EXT,
 337                                    GL_RENDERBUFFER_DEPTH_SIZE_EXT, &i);
 338    CheckError(__LINE__);
 339    printf("Depth renderbuffer size = %d bits\n", i);
 340    assert(i > 0);
 341
 342    /* attach DepthRB to MyFB */
 343    glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT,
 344                                 GL_RENDERBUFFER_EXT, DepthRB);
 345 #endif
 346
 347    CheckError(__LINE__);
 348
 349 #if STENCIL
 350    if (UsePackedDepthStencil) {
 351       /* DepthRb is a combined depth/stencil renderbuffer */
 352       glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT,
 353                                    GL_STENCIL_ATTACHMENT_EXT,
 354                                    GL_RENDERBUFFER_EXT, DepthRB);
 355    }
 356    else {
 357       /* make stencil renderbuffer */
 358       glGenRenderbuffersEXT(1, &StencilRB);
 359       assert(StencilRB);
 360       assert(!glIsRenderbufferEXT(StencilRB));
 361       glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, StencilRB);
 362       assert(glIsRenderbufferEXT(StencilRB));
 363       glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_STENCIL_INDEX,
 364                                TexWidth, TexHeight);
 365       /* attach StencilRB to MyFB */
 366       glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT,
 367                                    GL_STENCIL_ATTACHMENT_EXT,
 368                                    GL_RENDERBUFFER_EXT, StencilRB);
 369    }
 370    glGetRenderbufferParameterivEXT(GL_RENDERBUFFER_EXT,
 371                                    GL_RENDERBUFFER_STENCIL_SIZE_EXT, &i);
 372    CheckError(__LINE__);
 373    printf("Stencil renderbuffer size = %d bits\n", i);
 374    assert(i > 0);
 375 #endif
 376
 377    CheckError(__LINE__);
 378
 379    /* bind regular framebuffer */
 380    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
 381
 382
 383    /* lighting */
 384    glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, mat);
 385 }
 386
 387
 388 int
 389 main(int argc, char *argv[])
 390 {
 391    glutInit(&argc, argv);
 392    glutInitWindowPosition(0, 0);
 393    glutInitWindowSize(Width, Height);
 394    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);
 395    glutCreateWindow(argv[0]);
 396    glutReshapeFunc(Reshape);
 397    glutKeyboardFunc(Key);
 398    glutDisplayFunc(Display);
 399    if (Anim)
 400       glutIdleFunc(Idle);
 401    Init(argc, argv);
 402    glutMainLoop();
 403    return 0;
 404 }