#include <QApplication>
#include <QMainWindow>
#include <QPainter>

class View : public QWidget
{
public:
    View(int w) : QWidget(), lw(w) {
	setFixedSize(QSize(1500,1000));
	for(int x=-20000; x < 600000; x+=100)
	    polygon << QPoint(x,40000+qrand());
    }
    void paintEvent(QPaintEvent*) {
	QPainter p(this);
	p.translate(0,1000);
	p.scale(0.01,-0.01);
	QPen pen(Qt::black);
	pen.setCosmetic(true);
	pen.setWidth(lw);
	p.setPen(pen);
	//p.setClipRect(QRect(10000,10000,100000,80000));
	p.drawPolygon(polygon);
	
    }
private:
    QPolygon polygon;
    int lw;
};

int main(int argc, char** argv)
{
    QApplication app(argc,argv);
    QMainWindow* mw = new QMainWindow;
    mw->setCentralWidget(new View(argc > 1 ? QString(argv[1]).toInt() : 1));
    mw->show();
    app.exec();
    return 0;
}