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, StencilRB;
  36 static GLboolean Anim = GL_FALSE;
  37 static GLfloat Rot = 0.0;
  38 static GLboolean UsePackedDepthStencil = GL_FALSE;
  39 static GLuint TextureLevel = 1;  /* which texture level to render to */
  40 static GLenum TexIntFormat = GL_RGB; /* either GL_RGB or GL_RGBA */
  41
  42
  43 static void
  44 CheckError(int line)
  45 {
  46    GLenum err = glGetError();
  47    if (err) {
  48       printf("GL Error 0x%x at line %d\n", (int) err, line);
  49    }
  50 }
  51
  52
  53 static void
  54 Idle(void)
  55 {
  56    Rot = glutGet(GLUT_ELAPSED_TIME) * 0.1;
  57    glutPostRedisplay();
  58 }
  59
  60
  61 static void
  62 RenderTexture(void)
  63 {
  64    GLenum status;
  65
  66    glMatrixMode(GL_PROJECTION);
  67    glLoadIdentity();
  68    glOrtho(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0);
  69    glMatrixMode(GL_MODELVIEW);
  70    glLoadIdentity();
  71    glTranslatef(0.0, 0.0, -15.0);
  72
  73    /* draw to texture image */
  74    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, MyFB);
  75
  76    status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
  77    if (status != GL_FRAMEBUFFER_COMPLETE_EXT) {
  78       printf("Framebuffer incomplete!!!\n");
  79    }
  80
  81    glViewport(0, 0, TexWidth, TexHeight);
  82
  83    glClearColor(0.5, 0.5, 1.0, 0.0);
  84    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
  85    CheckError(__LINE__);
  86
  87 #if DEPTH
  88    glEnable(GL_DEPTH_TEST);
  89 #endif
  90
  91 #if STENCIL
  92    glEnable(GL_STENCIL_TEST);
  93    glStencilFunc(GL_NEVER, 1, ~0);
  94    glStencilOp(GL_REPLACE, GL_KEEP, GL_REPLACE);
  95 #endif
  96
  97    CheckError(__LINE__);
  98
  99 #if DEPTH || STENCIL
 100    /* draw diamond-shaped stencil pattern */
 101    glColor3f(0, 1, 0);
 102    glBegin(GL_POLYGON);
 103    glVertex2f(-0.2,  0.0);
 104    glVertex2f( 0.0, -0.2);
 105    glVertex2f( 0.2,  0.0);
 106    glVertex2f( 0.0,  0.2);
 107    glEnd();
 108 #endif
 109
 110    /* draw teapot where stencil != 1 */
 111 #if STENCIL
 112    glStencilFunc(GL_NOTEQUAL, 1, ~0);
 113    glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
 114 #endif
 115
 116    CheckError(__LINE__);
 117
 118 #if 0
 119    glBegin(GL_POLYGON);
 120    glColor3f(1, 0, 0);
 121    glVertex2f(-1, -1);
 122    glColor3f(0, 1, 0);
 123    glVertex2f(1, -1);
 124    glColor3f(0, 0, 1);
 125    glVertex2f(0, 1);
 126    glEnd();
 127 #else
 128    glEnable(GL_LIGHTING);
 129    glEnable(GL_LIGHT0);
 130    glPushMatrix();
 131    glRotatef(0.5 * Rot, 1.0, 0.0, 0.0);
 132    glutSolidTeapot(0.5);
 133    glPopMatrix();
 134    glDisable(GL_LIGHTING);
 135    /*
 136    PrintStencilHistogram(TexWidth, TexHeight);
 137    */
 138 #endif
 139
 140    glDisable(GL_DEPTH_TEST);
 141    glDisable(GL_STENCIL_TEST);
 142
 143 #if DRAW
 144    /* Bind normal framebuffer */
 145    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
 146 #endif
 147
 148    CheckError(__LINE__);
 149 }
 150
 151
 152
 153 static void
 154 Display(void)
 155 {
 156    float ar = (float) Width / (float) Height;
 157
 158    RenderTexture();
 159
 160    /* draw textured quad in the window */
 161 #if DRAW
 162    glMatrixMode(GL_PROJECTION);
 163    glLoadIdentity();
 164    glFrustum(-ar, ar, -1.0, 1.0, 5.0, 25.0);
 165    glMatrixMode(GL_MODELVIEW);
 166    glLoadIdentity();
 167    glTranslatef(0.0, 0.0, -7.0);
 168
 169    glViewport(0, 0, Width, Height);
 170
 171    glClearColor(0.25, 0.25, 0.25, 0);
 172    glClear(GL_COLOR_BUFFER_BIT);
 173
 174    glPushMatrix();
 175    glRotatef(Rot, 0, 1, 0);
 176    glEnable(TexTarget);
 177    glBindTexture(TexTarget, TexObj);
 178    glBegin(GL_POLYGON);
 179    glColor3f(0.25, 0.25, 0.25);
 180    if (TexTarget == GL_TEXTURE_2D) {
 181       glTexCoord2f(0, 0);
 182       glVertex2f(-1, -1);
 183       glTexCoord2f(1, 0);
 184       glVertex2f(1, -1);
 185       glColor3f(1.0, 1.0, 1.0);
 186       glTexCoord2f(1, 1);
 187       glVertex2f(1, 1);
 188       glTexCoord2f(0, 1);
 189       glVertex2f(-1, 1);
 190    }
 191    else {
 192       assert(TexTarget == GL_TEXTURE_RECTANGLE_ARB);
 193       glTexCoord2f(0, 0);
 194       glVertex2f(-1, -1);
 195       glTexCoord2f(TexWidth, 0);
 196       glVertex2f(1, -1);
 197       glColor3f(1.0, 1.0, 1.0);
 198       glTexCoord2f(TexWidth, TexHeight);
 199       glVertex2f(1, 1);
 200       glTexCoord2f(0, TexHeight);
 201       glVertex2f(-1, 1);
 202    }
 203    glEnd();
 204    glPopMatrix();
 205    glDisable(TexTarget);
 206 #endif
 207
 208    glutSwapBuffers();
 209    CheckError(__LINE__);
 210 }
 211
 212
 213 static void
 214 Reshape(int width, int height)
 215 {
 216    glViewport(0, 0, width, height);
 217    Width = width;
 218    Height = height;
 219 }
 220
 221
 222 static void
 223 CleanUp(void)
 224 {
 225 #if DEPTH
 226    glDeleteRenderbuffersEXT(1, &DepthRB);
 227 #endif
 228 #if STENCIL
 229    if (!UsePackedDepthStencil)
 230       glDeleteRenderbuffersEXT(1, &StencilRB);
 231 #endif
 232    glDeleteFramebuffersEXT(1, &MyFB);
 233
 234    glDeleteTextures(1, &TexObj);
 235
 236    glutDestroyWindow(Win);
 237
 238    exit(0);
 239 }
 240
 241
 242 static void
 243 Key(unsigned char key, int x, int y)
 244 {
 245    (void) x;
 246    (void) y;
 247    switch (key) {
 248       case 'a':
 249          Anim = !Anim;
 250          if (Anim)
 251             glutIdleFunc(Idle);
 252          else
 253             glutIdleFunc(NULL);
 254          break;
 255       case 's':
 256          Rot += 2.0;
 257          break;
 258       case 27:
 259          CleanUp();
 260          break;
 261    }
 262    glutPostRedisplay();
 263 }
 264
 265
 266 static void
 267 Init(int argc, char *argv[])
 268 {
 269    static const GLfloat mat[4] = { 1.0, 0.5, 0.5, 1.0 };
 270    GLint i;
 271
 272    if (!glutExtensionSupported("GL_EXT_framebuffer_object")) {
 273       printf("GL_EXT_framebuffer_object not found!\n");
 274       exit(0);
 275    }
 276
 277    if (argc > 1 && strcmp(argv[1], "-ds") == 0) {
 278       if (!glutExtensionSupported("GL_EXT_packed_depth_stencil")) {
 279          printf("GL_EXT_packed_depth_stencil not found!\n");
 280          exit(0);
 281       }
 282       UsePackedDepthStencil = GL_TRUE;
 283       printf("Using GL_EXT_packed_depth_stencil\n");
 284    }
 285
 286    printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
 287
 288    /* gen framebuffer id, delete it, do some assertions, just for testing */
 289    glGenFramebuffersEXT(1, &MyFB);
 290    assert(MyFB);
 291    assert(!glIsFramebufferEXT(MyFB));
 292    glDeleteFramebuffersEXT(1, &MyFB);
 293    assert(!glIsFramebufferEXT(MyFB));
 294    /* Note, continue to use MyFB below */
 295
 296    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, MyFB);
 297    assert(glIsFramebufferEXT(MyFB));
 298    glGetIntegerv(GL_FRAMEBUFFER_BINDING_EXT, &i);
 299    assert(i == MyFB);
 300
 301    /* Make texture object/image */
 302    glGenTextures(1, &TexObj);
 303    glBindTexture(TexTarget, TexObj);
 304    /* make two image levels */
 305    glTexImage2D(TexTarget, 0, TexIntFormat, TexWidth, TexHeight, 0,
 306                 GL_RGBA, GL_UNSIGNED_BYTE, NULL);
 307    glTexImage2D(TexTarget, 1, TexIntFormat, TexWidth/2, TexHeight/2, 0,
 308                 GL_RGBA, GL_UNSIGNED_BYTE, NULL);
 309    TexWidth = TexWidth >> TextureLevel;
 310    TexHeight = TexHeight >> TextureLevel;
 311
 312    glTexParameteri(TexTarget, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 313    glTexParameteri(TexTarget, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 314    glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
 315    glTexParameteri(TexTarget, GL_TEXTURE_BASE_LEVEL, TextureLevel);
 316    glTexParameteri(TexTarget, GL_TEXTURE_MAX_LEVEL, TextureLevel);
 317
 318    CheckError(__LINE__);
 319
 320    /* Render color to texture */
 321    glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
 322                              TexTarget, TexObj, TextureLevel);
 323
 324
 325 #if DEPTH
 326    /* make depth renderbuffer */
 327    glGenRenderbuffersEXT(1, &DepthRB);
 328    assert(DepthRB);
 329    assert(!glIsRenderbufferEXT(DepthRB));
 330    glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, DepthRB);
 331    assert(glIsRenderbufferEXT(DepthRB));
 332    if (UsePackedDepthStencil)
 333       glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_STENCIL_EXT,
 334                                TexWidth, TexHeight);
 335    else
 336       glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT,
 337                                TexWidth, TexHeight);
 338    CheckError(__LINE__);
 339    glGetRenderbufferParameterivEXT(GL_RENDERBUFFER_EXT,
 340                                    GL_RENDERBUFFER_DEPTH_SIZE_EXT, &i);
 341    CheckError(__LINE__);
 342    printf("Depth renderbuffer size = %d bits\n", i);
 343    assert(i > 0);
 344
 345    /* attach DepthRB to MyFB */
 346    glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT,
 347                                 GL_RENDERBUFFER_EXT, DepthRB);
 348 #endif
 349
 350    CheckError(__LINE__);
 351
 352 #if STENCIL
 353    if (UsePackedDepthStencil) {
 354       /* DepthRb is a combined depth/stencil renderbuffer */
 355       glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT,
 356                                    GL_STENCIL_ATTACHMENT_EXT,
 357                                    GL_RENDERBUFFER_EXT, DepthRB);
 358    }
 359    else {
 360       /* make stencil renderbuffer */
 361       glGenRenderbuffersEXT(1, &StencilRB);
 362       assert(StencilRB);
 363       assert(!glIsRenderbufferEXT(StencilRB));
 364       glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, StencilRB);
 365       assert(glIsRenderbufferEXT(StencilRB));
 366       glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_STENCIL_INDEX,
 367                                TexWidth, TexHeight);
 368       /* attach StencilRB to MyFB */
 369       glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT,
 370                                    GL_STENCIL_ATTACHMENT_EXT,
 371                                    GL_RENDERBUFFER_EXT, StencilRB);
 372    }
 373    glGetRenderbufferParameterivEXT(GL_RENDERBUFFER_EXT,
 374                                    GL_RENDERBUFFER_STENCIL_SIZE_EXT, &i);
 375    CheckError(__LINE__);
 376    printf("Stencil renderbuffer size = %d bits\n", i);
 377    assert(i > 0);
 378 #endif
 379
 380    CheckError(__LINE__);
 381
 382    /* bind regular framebuffer */
 383    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
 384
 385
 386    /* lighting */
 387    glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, mat);
 388 }
 389
 390
 391 int
 392 main(int argc, char *argv[])
 393 {
 394    glutInit(&argc, argv);
 395    glutInitWindowPosition(0, 0);
 396    glutInitWindowSize(Width, Height);
 397    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);
 398    Win = glutCreateWindow(argv[0]);
 399    glutReshapeFunc(Reshape);
 400    glutKeyboardFunc(Key);
 401    glutDisplayFunc(Display);
 402    if (Anim)
 403       glutIdleFunc(Idle);
 404    Init(argc, argv);
 405    glutMainLoop();
 406    return 0;
 407 }