if (False == glXMakeCurrent(_pDisplay, _hPBuffer, _hGLContext))
{
dbg_printf( "glXMakeCurrent(_pDisplay, _hPBuffer, _hGLContext) FAILED. return false\n" );
if (False == glXMakeCurrent(_pDisplay, _hPBuffer, _hGLContext))
{
dbg_printf( "glXMakeCurrent(_pDisplay, _hPBuffer, _hGLContext) FAILED. return false\n" );