Скриншот на OpenGL (3 стр)

#pragma pack (push, 1)
struct  TgaHeader
{
  byte  idLength;
  byte  colormapType;
  byte  imageType;
  uint16  colormapIndex;
  uint16  colormapLength;
  byte  colormapEntrySize;
  uint16  xOrigin;
  uint16  yOrigin;
  uint16  width;
  uint16  height;
  byte  pixelSize;
  byte  imageDesc;
};
#pragma  pack (pop)

bool  saveScreenShot ( const char * fileName )
{
  int     width  = glutGet ( GLUT_WINDOW_WIDTH  );
  int     height = glutGet ( GLUT_WINDOW_HEIGHT );
  byte * ptr    = (byte *) malloc ( 3 * width * height );

  if ( ptr == NULL )
    return false;

                      // get image from window
  glReadBuffer ( GL_FRONT );
  glReadPixels ( 0, 0, width, height, GL_RGB, GL_UNSIGNED_BYTE, ptr );

                      // now save it as 24-bit uncompressed tga
  TgaHeader  hdr;

  memset ( &hdr, '\0', sizeof ( hdr ) );

  hdr.imageType         = 2;         // unencoded image
  hdr.width             = width;
  hdr.height            = height;
  hdr.pixelSize         = 24;

  int  file = open ( fileName, O_WRONLY | O_BINARY | O_CREAT, S_IWRITE );

  if ( file == -1 )
  {
    free ( ptr );

    return false;
  }
                      // write header
  write ( file, &hdr, sizeof ( hdr ) );


                      // swap R and B channels
  int    numPixels = width * height;
  byte  * pixel     = ptr;
  byte  temp;

  for ( int i = 0; i < numPixels; i++, pixel += 3 )
  {
    temp      = pixel [0];
    pixel [0] = pixel [2];
    pixel [2] = temp;
  }
                      // and write it down
  write ( file, ptr, width * height * 3 );
  close ( file );
                      // cleanup
  free ( ptr );

  return true;
}