This prevents girders from erasing landbacktex (square windows in tunnels and such), at the cost of requiring lfBasic and lfObject to be treated the same apart from graphically
#include <QtGui/QApplication>
#include "mainwindow.h"
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MainWindow w;
w.show();
return a.exec();
}