progs/tests/fbotest3.c

   1 /*
   2  * Test GL_EXT_framebuffer_object
   3  * Like fbotest2.c but use a texture for the Z buffer / renderbuffer.
   4  * Note: the Z texture is never resized so that limits what can be
   5  * rendered if the window is resized.
   6  *
   7  * This tests a bug reported by Christoph Bumiller on 1 Feb 2010
   8  * on mesa3d-dev.
   9  *
  10  * XXX this should be made into a piglit test.
  11  *
  12  * Brian Paul
  13  * 1 Feb 2010
  14  */
  15
  16
  17 #include <assert.h>
  18 #include <stdio.h>
  19 #include <stdlib.h>
  20 #include <math.h>
  21 #include <GL/glew.h>
  22 #include <GL/glut.h>
  23
  24
  25 static int Win = 0;
  26 static int Width = 400, Height = 400;
  27 static GLuint Tex = 0;
  28 static GLuint MyFB, ColorRb, DepthRb;
  29 static GLboolean Animate = GL_FALSE;
  30 static GLfloat Rotation = 0.0;
  31
  32
  33 static void
  34 CheckError(int line)
  35 {
  36    GLenum err = glGetError();
  37    if (err) {
  38       printf("fbotest3: GL Error 0x%x at line %d\n", (int) err, line);
  39    }
  40 }
  41
  42
  43 static void
  44 Display( void )
  45 {
  46    GLubyte *buffer = malloc(Width * Height * 4);
  47    GLenum status;
  48
  49    CheckError(__LINE__);
  50
  51    /* draw to user framebuffer */
  52    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, MyFB);
  53    glDrawBuffer(GL_COLOR_ATTACHMENT0_EXT);
  54    glReadBuffer(GL_COLOR_ATTACHMENT0_EXT);
  55
  56    status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
  57    if (status != GL_FRAMEBUFFER_COMPLETE_EXT) {
  58       printf("fbotest3: Error: Framebuffer is incomplete!!!\n");
  59    }
  60
  61    CheckError(__LINE__);
  62
  63    glClearColor(0.5, 0.5, 1.0, 0.0);
  64    glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
  65
  66    glEnable(GL_DEPTH_TEST);
  67    glEnable(GL_LIGHTING);
  68    glEnable(GL_LIGHT0);
  69
  70    glPushMatrix();
  71    glRotatef(30.0, 1, 0, 0);
  72    glRotatef(Rotation, 0, 1, 0);
  73    glutSolidTeapot(2.0);
  74    glPopMatrix();
  75
  76    /* read from user framebuffer */
  77    glReadPixels(0, 0, Width, Height, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
  78
  79    /* draw to window */
  80    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
  81    glDisable(GL_DEPTH_TEST);  /* in case window has depth buffer */
  82    glWindowPos2iARB(0, 0);
  83    glDrawPixels(Width, Height, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
  84
  85    free(buffer);
  86    glutSwapBuffers();
  87    CheckError(__LINE__);
  88 }
  89
  90
  91 static void
  92 Reshape( int width, int height )
  93 {
  94    float ar = (float) width / (float) height;
  95
  96    glViewport( 0, 0, width, height );
  97    glMatrixMode( GL_PROJECTION );
  98    glLoadIdentity();
  99    glFrustum( -ar, ar, -1.0, 1.0, 5.0, 25.0 );
 100
 101    glMatrixMode( GL_MODELVIEW );
 102    glLoadIdentity();
 103    glTranslatef( 0.0, 0.0, -15.0 );
 104
 105    glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, ColorRb);
 106    glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_RGB, width, height);
 107
 108    Width = width;
 109    Height = height;
 110 }
 111
 112
 113 static void
 114 CleanUp(void)
 115 {
 116    glDeleteFramebuffersEXT(1, &MyFB);
 117    glDeleteRenderbuffersEXT(1, &ColorRb);
 118    glDeleteRenderbuffersEXT(1, &DepthRb);
 119    glDeleteTextures(1, &Tex);
 120    assert(!glIsFramebufferEXT(MyFB));
 121    assert(!glIsRenderbufferEXT(ColorRb));
 122    assert(!glIsRenderbufferEXT(DepthRb));
 123    glutDestroyWindow(Win);
 124    exit(0);
 125 }
 126
 127
 128 static void
 129 Idle(void)
 130 {
 131    Rotation = glutGet(GLUT_ELAPSED_TIME) * 0.1;
 132    glutPostRedisplay();
 133 }
 134
 135
 136 static void
 137 Key( unsigned char key, int x, int y )
 138 {
 139    (void) x;
 140    (void) y;
 141    switch (key) {
 142    case 'a':
 143       Animate = !Animate;
 144       if (Animate)
 145          glutIdleFunc(Idle);
 146       else
 147          glutIdleFunc(NULL);
 148       break;
 149    case 27:
 150       CleanUp();
 151       break;
 152    }
 153    glutPostRedisplay();
 154 }
 155
 156
 157 static void
 158 Init( void )
 159 {
 160    if (!glutExtensionSupported("GL_EXT_framebuffer_object")) {
 161       printf("fbotest3: GL_EXT_framebuffer_object not found!\n");
 162       exit(0);
 163    }
 164    printf("fbotest3: GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
 165
 166    /* create initial tex obj as an RGBA texture */
 167    glGenTextures(1, &Tex);
 168    glBindTexture(GL_TEXTURE_2D, Tex);
 169    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 256, 256, 0,
 170                 GL_RGBA, GL_UNSIGNED_BYTE, NULL);
 171    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
 172    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
 173    glEnable(GL_TEXTURE_2D);
 174
 175    /* draw something to make sure the texture is used */
 176    glBegin(GL_POINTS);
 177    glVertex2f(0, 0);
 178    glEnd();
 179
 180    /* done w/ texturing */
 181    glDisable(GL_TEXTURE_2D);
 182
 183    /* Create my Framebuffer Object */
 184    glGenFramebuffersEXT(1, &MyFB);
 185    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, MyFB);
 186    assert(glIsFramebufferEXT(MyFB));
 187
 188    /* Setup color renderbuffer */
 189    glGenRenderbuffersEXT(1, &ColorRb);
 190    glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, ColorRb);
 191    assert(glIsRenderbufferEXT(ColorRb));
 192    glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
 193                                 GL_RENDERBUFFER_EXT, ColorRb);
 194    glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_RGB, Width, Height);
 195
 196    /* Setup depth renderbuffer (a texture) */
 197    glGenRenderbuffersEXT(1, &DepthRb);
 198    glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, DepthRb);
 199    assert(glIsRenderbufferEXT(DepthRb));
 200    /* replace RGBA texture with Z texture */
 201    glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, Width, Height, 0,
 202                 GL_DEPTH_COMPONENT, GL_UNSIGNED_INT, NULL);
 203    glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT,
 204                              GL_TEXTURE_2D, Tex, 0);
 205
 206    CheckError(__LINE__);
 207
 208    /* restore to default */
 209    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
 210    CheckError(__LINE__);
 211 }
 212
 213
 214 int
 215 main( int argc, char *argv[] )
 216 {
 217    glutInit( &argc, argv );
 218    glutInitWindowPosition( 0, 0 );
 219    glutInitWindowSize(Width, Height);
 220    glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE );
 221    Win = glutCreateWindow(argv[0]);
 222    glewInit();
 223    glutReshapeFunc( Reshape );
 224    glutKeyboardFunc( Key );
 225    glutDisplayFunc( Display );
 226    if (Animate)
 227       glutIdleFunc(Idle);
 228    Init();
 229    glutMainLoop();
 230    return 0;
 231 }