progs/tests/fbotest2.c

   1 /*
   2  * Test GL_EXT_framebuffer_object
   3  *
   4  * Brian Paul
   5  * 19 Mar 2006
   6  */
   7
   8
   9 #include <assert.h>
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <math.h>
  13 #include <GL/glew.h>
  14 #include <GL/glut.h>
  15
  16 static int Win = 0;
  17 static int Width = 400, Height = 400;
  18 static GLuint MyFB, ColorRb, DepthRb;
  19 static GLboolean Animate = GL_TRUE;
  20 static GLfloat Rotation = 0.0;
  21
  22
  23 static void
  24 CheckError(int line)
  25 {
  26    GLenum err = glGetError();
  27    if (err) {
  28       printf("fbotest2: GL Error 0x%x at line %d\n", (int) err, line);
  29    }
  30 }
  31
  32
  33 static void
  34 Display( void )
  35 {
  36    GLubyte *buffer = malloc(Width * Height * 4);
  37    GLenum status;
  38
  39    CheckError(__LINE__);
  40
  41    /* draw to user framebuffer */
  42    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, MyFB);
  43    glDrawBuffer(GL_COLOR_ATTACHMENT1_EXT);
  44    glReadBuffer(GL_COLOR_ATTACHMENT1_EXT);
  45
  46    status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
  47    if (status != GL_FRAMEBUFFER_COMPLETE_EXT) {
  48       printf("fbotest2: Error: Framebuffer is incomplete!!!\n");
  49    }
  50
  51    CheckError(__LINE__);
  52
  53    glClearColor(0.5, 0.5, 1.0, 0.0);
  54    glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
  55
  56    glEnable(GL_DEPTH_TEST);
  57    glEnable(GL_LIGHTING);
  58    glEnable(GL_LIGHT0);
  59
  60    glPushMatrix();
  61    glRotatef(30.0, 1, 0, 0);
  62    glRotatef(Rotation, 0, 1, 0);
  63    glutSolidTeapot(2.0);
  64    glPopMatrix();
  65
  66    /* read from user framebuffer */
  67    glReadPixels(0, 0, Width, Height, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
  68
  69    /* draw to window */
  70    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
  71    glDisable(GL_DEPTH_TEST);  /* in case window has depth buffer */
  72    glWindowPos2iARB(0, 0);
  73    glDrawPixels(Width, Height, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
  74
  75    free(buffer);
  76    glutSwapBuffers();
  77    CheckError(__LINE__);
  78 }
  79
  80
  81 static void
  82 Reshape( int width, int height )
  83 {
  84    float ar = (float) width / (float) height;
  85
  86    glViewport( 0, 0, width, height );
  87    glMatrixMode( GL_PROJECTION );
  88    glLoadIdentity();
  89    glFrustum( -ar, ar, -1.0, 1.0, 5.0, 25.0 );
  90
  91    glMatrixMode( GL_MODELVIEW );
  92    glLoadIdentity();
  93    glTranslatef( 0.0, 0.0, -15.0 );
  94
  95    glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, ColorRb);
  96    glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_RGB, width, height);
  97    glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, DepthRb);
  98    glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT,
  99                             width, height);
 100
 101    Width = width;
 102    Height = height;
 103 }
 104
 105
 106 static void
 107 CleanUp(void)
 108 {
 109    glDeleteFramebuffersEXT(1, &MyFB);
 110    glDeleteRenderbuffersEXT(1, &ColorRb);
 111    glDeleteRenderbuffersEXT(1, &DepthRb);
 112    assert(!glIsFramebufferEXT(MyFB));
 113    assert(!glIsRenderbufferEXT(ColorRb));
 114    assert(!glIsRenderbufferEXT(DepthRb));
 115    glutDestroyWindow(Win);
 116    exit(0);
 117 }
 118
 119
 120 static void
 121 Idle(void)
 122 {
 123    Rotation = glutGet(GLUT_ELAPSED_TIME) * 0.1;
 124    glutPostRedisplay();
 125 }
 126
 127
 128 static void
 129 Key( unsigned char key, int x, int y )
 130 {
 131    (void) x;
 132    (void) y;
 133    switch (key) {
 134    case 'a':
 135       Animate = !Animate;
 136       if (Animate)
 137          glutIdleFunc(Idle);
 138       else
 139          glutIdleFunc(NULL);
 140       break;
 141    case 27:
 142       CleanUp();
 143       break;
 144    }
 145    glutPostRedisplay();
 146 }
 147
 148
 149 static void
 150 Init( void )
 151 {
 152    if (!glutExtensionSupported("GL_EXT_framebuffer_object")) {
 153       printf("fbotest2: GL_EXT_framebuffer_object not found!\n");
 154       exit(0);
 155    }
 156    printf("fbotest2: GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
 157
 158    glGenFramebuffersEXT(1, &MyFB);
 159    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, MyFB);
 160    assert(glIsFramebufferEXT(MyFB));
 161
 162    /* set color buffer */
 163    glGenRenderbuffersEXT(1, &ColorRb);
 164    glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, ColorRb);
 165    assert(glIsRenderbufferEXT(ColorRb));
 166    glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT1_EXT,
 167                                 GL_RENDERBUFFER_EXT, ColorRb);
 168    glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_RGB, Width, Height);
 169
 170    /* setup depth buffer */
 171    glGenRenderbuffersEXT(1, &DepthRb);
 172    glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, DepthRb);
 173    assert(glIsRenderbufferEXT(DepthRb));
 174    glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT,
 175                                 GL_RENDERBUFFER_EXT, DepthRb);
 176    glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT, Width, Height);
 177
 178    CheckError(__LINE__);
 179
 180    /* restore to default */
 181    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
 182    CheckError(__LINE__);
 183 }
 184
 185
 186 int
 187 main( int argc, char *argv[] )
 188 {
 189    glutInit( &argc, argv );
 190    glutInitWindowPosition( 0, 0 );
 191    glutInitWindowSize(Width, Height);
 192    glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE );
 193    Win = glutCreateWindow(argv[0]);
 194    glewInit();
 195    glutReshapeFunc( Reshape );
 196    glutKeyboardFunc( Key );
 197    glutDisplayFunc( Display );
 198    if (Animate)
 199       glutIdleFunc(Idle);
 200    Init();
 201    glutMainLoop();
 202    return 0;
 203 }