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