progs/tests/fbotest2.c

   1 /*
   2  * Test GL_EXT_framebuffer_object
   3  *
   4  * Brian Paul
   5  * 19 Mar 2006
   6  */
   7
   8
   9 #define GL_GLEXT_PROTOTYPES
  10 #include <assert.h>
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <math.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    glWindowPos2iARB(0, 0);
  72    glDrawPixels(Width, Height, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
  73
  74    free(buffer);
  75    glutSwapBuffers();
  76    CheckError(__LINE__);
  77 }
  78
  79
  80 static void
  81 Reshape( int width, int height )
  82 {
  83    float ar = (float) width / (float) height;
  84
  85    glViewport( 0, 0, width, height );
  86    glMatrixMode( GL_PROJECTION );
  87    glLoadIdentity();
  88    glFrustum( -ar, ar, -1.0, 1.0, 5.0, 25.0 );
  89
  90    glMatrixMode( GL_MODELVIEW );
  91    glLoadIdentity();
  92    glTranslatef( 0.0, 0.0, -15.0 );
  93
  94    glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, ColorRb);
  95    glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_RGB, width, height);
  96    glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, DepthRb);
  97    glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT,
  98                             width, height);
  99
 100    Width = width;
 101    Height = height;
 102 }
 103
 104
 105 static void
 106 CleanUp(void)
 107 {
 108    glDeleteFramebuffersEXT(1, &MyFB);
 109    glDeleteRenderbuffersEXT(1, &ColorRb);
 110    glDeleteRenderbuffersEXT(1, &DepthRb);
 111    assert(!glIsFramebufferEXT(MyFB));
 112    assert(!glIsRenderbufferEXT(ColorRb));
 113    assert(!glIsRenderbufferEXT(DepthRb));
 114    glutDestroyWindow(Win);
 115    exit(0);
 116 }
 117
 118
 119 static void
 120 Idle(void)
 121 {
 122    Rotation = glutGet(GLUT_ELAPSED_TIME) * 0.1;
 123    glutPostRedisplay();
 124 }
 125
 126
 127 static void
 128 Key( unsigned char key, int x, int y )
 129 {
 130    (void) x;
 131    (void) y;
 132    switch (key) {
 133    case 'a':
 134       Animate = !Animate;
 135       if (Animate)
 136          glutIdleFunc(Idle);
 137       else
 138          glutIdleFunc(NULL);
 139       break;
 140    case 27:
 141       CleanUp();
 142       break;
 143    }
 144    glutPostRedisplay();
 145 }
 146
 147
 148 static void
 149 Init( void )
 150 {
 151    if (!glutExtensionSupported("GL_EXT_framebuffer_object")) {
 152       printf("fbotest2: GL_EXT_framebuffer_object not found!\n");
 153       exit(0);
 154    }
 155    printf("fbotest2: GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
 156
 157    glGenFramebuffersEXT(1, &MyFB);
 158    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, MyFB);
 159    assert(glIsFramebufferEXT(MyFB));
 160
 161    /* set color buffer */
 162    glGenRenderbuffersEXT(1, &ColorRb);
 163    glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, ColorRb);
 164    assert(glIsRenderbufferEXT(ColorRb));
 165    glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT1_EXT,
 166                                 GL_RENDERBUFFER_EXT, ColorRb);
 167    glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_RGB, Width, Height);
 168
 169    /* setup depth buffer */
 170    glGenRenderbuffersEXT(1, &DepthRb);
 171    glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, DepthRb);
 172    assert(glIsRenderbufferEXT(DepthRb));
 173    glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT,
 174                                 GL_RENDERBUFFER_EXT, DepthRb);
 175    glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT, Width, Height);
 176
 177    CheckError(__LINE__);
 178
 179    /* restore to default */
 180    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
 181    CheckError(__LINE__);
 182 }
 183
 184
 185 int
 186 main( int argc, char *argv[] )
 187 {
 188    glutInit( &argc, argv );
 189    glutInitWindowPosition( 0, 0 );
 190    glutInitWindowSize(Width, Height);
 191    glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE );
 192    Win = glutCreateWindow(argv[0]);
 193    glutReshapeFunc( Reshape );
 194    glutKeyboardFunc( Key );
 195    glutDisplayFunc( Display );
 196    if (Animate)
 197       glutIdleFunc(Idle);
 198    Init();
 199    glutMainLoop();
 200    return 0;
 201 }