#include <QtOpenGL/QtOpenGL>
#include <QtWidgets/QtWidgets>

int main(int argc, char *argv[])
{
	QApplication app(argc, argv);

	// create QMainWindow and QMdiArea
	QMainWindow* mainWnd = new QMainWindow();
	QMdiArea* mdi = new QMdiArea(mainWnd);
	mainWnd->setCentralWidget(mdi);
	mainWnd->show();
	app.setActiveWindow(mainWnd);

	// when desktop size is 1920x1200;
	// create one QMdiSubWindow
	// This can be resize properly
	QMdiSubWindow* subWnd1 = mdi->addSubWindow(new QGLWidget());
	subWnd1->resize(1920, 1200);
	subWnd1->show();

	// create another one
	// This can't be resize
	QMdiSubWindow* subWnd2 = mdi->addSubWindow(new QGLWidget());
	subWnd2->resize(1920, 1200);
	subWnd2->show();

	return app.exec();
}