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    GLboolean copyPix = GL_FALSE;
  37    GLboolean blitPix = GL_FALSE;
  38    GLenum status;
  39
  40    CheckError(__LINE__);
  41
  42    /* draw to user framebuffer */
  43    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, MyFB);
  44    glDrawBuffer(GL_COLOR_ATTACHMENT0_EXT);
  45    glReadBuffer(GL_COLOR_ATTACHMENT0_EXT);
  46
  47    status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
  48    if (status != GL_FRAMEBUFFER_COMPLETE_EXT) {
  49       printf("fbotest2: Error: Framebuffer is incomplete!!!\n");
  50    }
  51
  52    CheckError(__LINE__);
  53
  54    glClearColor(0.5, 0.5, 1.0, 0.0);
  55    glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
  56
  57    glEnable(GL_DEPTH_TEST);
  58    glEnable(GL_LIGHTING);
  59    glEnable(GL_LIGHT0);
  60
  61    glPushMatrix();
  62    glRotatef(30.0, 1, 0, 0);
  63    glRotatef(Rotation, 0, 1, 0);
  64    glutSolidTeapot(2.0);
  65    glPopMatrix();
  66
  67    if (copyPix) {
  68       glBindFramebufferEXT(GL_READ_FRAMEBUFFER_EXT, MyFB);
  69       glReadBuffer(GL_COLOR_ATTACHMENT0_EXT);
  70       glBindFramebufferEXT(GL_DRAW_FRAMEBUFFER_EXT, 0);
  71       glDrawBuffer(GL_BACK);
  72
  73       glDisable(GL_DEPTH_TEST);  /* in case window has depth buffer */
  74
  75       glWindowPos2iARB(0, 0);
  76       glCopyPixels(0, 0, Width, Height, GL_COLOR);
  77    }
  78    else if (blitPix) {
  79       glBindFramebufferEXT(GL_READ_FRAMEBUFFER_EXT, MyFB);
  80       glReadBuffer(GL_COLOR_ATTACHMENT0_EXT);
  81       glBindFramebufferEXT(GL_DRAW_FRAMEBUFFER_EXT, 0);
  82       glDrawBuffer(GL_BACK);
  83
  84       glDisable(GL_DEPTH_TEST);  /* in case window has depth buffer */
  85
  86       glBlitFramebufferEXT(0, 0, Width, Height,
  87                            0, 0, Width, Height,
  88                            GL_COLOR_BUFFER_BIT, GL_NEAREST);
  89    }
  90    else {
  91       GLubyte *buffer = malloc(Width * Height * 4);
  92       /* read from user framebuffer */
  93       glReadPixels(0, 0, Width, Height, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
  94
  95       /* draw to window */
  96       glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
  97       glDisable(GL_DEPTH_TEST);  /* in case window has depth buffer */
  98       glWindowPos2iARB(0, 0);
  99       glDrawPixels(Width, Height, GL_RGBA, GL_UNSIGNED_BYTE, buffer);
 100
 101       free(buffer);
 102    }
 103
 104    glutSwapBuffers();
 105    CheckError(__LINE__);
 106 }
 107
 108
 109 static void
 110 Reshape( int width, int height )
 111 {
 112    float ar = (float) width / (float) height;
 113
 114    glViewport( 0, 0, width, height );
 115    glMatrixMode( GL_PROJECTION );
 116    glLoadIdentity();
 117    glFrustum( -ar, ar, -1.0, 1.0, 5.0, 25.0 );
 118
 119    glMatrixMode( GL_MODELVIEW );
 120    glLoadIdentity();
 121    glTranslatef( 0.0, 0.0, -15.0 );
 122
 123    glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, ColorRb);
 124    glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_RGB, width, height);
 125    glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, DepthRb);
 126    glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT,
 127                             width, height);
 128
 129    Width = width;
 130    Height = height;
 131 }
 132
 133
 134 static void
 135 CleanUp(void)
 136 {
 137    glDeleteFramebuffersEXT(1, &MyFB);
 138    glDeleteRenderbuffersEXT(1, &ColorRb);
 139    glDeleteRenderbuffersEXT(1, &DepthRb);
 140    assert(!glIsFramebufferEXT(MyFB));
 141    assert(!glIsRenderbufferEXT(ColorRb));
 142    assert(!glIsRenderbufferEXT(DepthRb));
 143    glutDestroyWindow(Win);
 144    exit(0);
 145 }
 146
 147
 148 static void
 149 Idle(void)
 150 {
 151    Rotation = glutGet(GLUT_ELAPSED_TIME) * 0.1;
 152    glutPostRedisplay();
 153 }
 154
 155
 156 static void
 157 Key( unsigned char key, int x, int y )
 158 {
 159    (void) x;
 160    (void) y;
 161    switch (key) {
 162    case 'a':
 163       Animate = !Animate;
 164       if (Animate)
 165          glutIdleFunc(Idle);
 166       else
 167          glutIdleFunc(NULL);
 168       break;
 169    case 27:
 170       CleanUp();
 171       break;
 172    }
 173    glutPostRedisplay();
 174 }
 175
 176
 177 static void
 178 Init( void )
 179 {
 180    if (!glutExtensionSupported("GL_EXT_framebuffer_object")) {
 181       printf("fbotest2: GL_EXT_framebuffer_object not found!\n");
 182       exit(0);
 183    }
 184    printf("fbotest2: GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
 185
 186    glGenFramebuffersEXT(1, &MyFB);
 187    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, MyFB);
 188    assert(glIsFramebufferEXT(MyFB));
 189
 190    /* set color buffer */
 191    glGenRenderbuffersEXT(1, &ColorRb);
 192    glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, ColorRb);
 193    assert(glIsRenderbufferEXT(ColorRb));
 194    glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
 195                                 GL_RENDERBUFFER_EXT, ColorRb);
 196    glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_RGB, Width, Height);
 197
 198    /* setup depth buffer */
 199    glGenRenderbuffersEXT(1, &DepthRb);
 200    glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, DepthRb);
 201    assert(glIsRenderbufferEXT(DepthRb));
 202    glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT,
 203                                 GL_RENDERBUFFER_EXT, DepthRb);
 204    glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT, Width, Height);
 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 }