#include <QtGui/QApplication>
#include <QtGui/QMainWindow>
#include <QtGui/QGraphicsView>
#include <QtGui/QGraphicsScene>
#include <QtGui/QGraphicsPolygonItem>


int main(int argc, char *argv[])
{
   QApplication app(argc, argv);
   
   QMainWindow* win = new QMainWindow();

   win->resize(600, 400);
   QGraphicsView* graphicsView = new QGraphicsView(win);
   win->setCentralWidget(graphicsView);
   QGraphicsScene* graphicsScene = new QGraphicsScene(win);
   graphicsView->setScene(graphicsScene);

   graphicsScene->setBackgroundBrush(QBrush(Qt::darkGray));

   int radius = 8;
   QPolygonF diamond;
   diamond.push_back(QPointF(-radius,0));
   diamond.push_back(QPointF(0,-radius));
   diamond.push_back(QPointF(radius,0));
   diamond.push_back(QPointF(0,radius));

   QGraphicsPolygonItem* polygonItem = graphicsScene->addPolygon(diamond, QPen(Qt::red), QBrush(Qt::green));
   polygonItem->setPos(702.469,128.299);

   win->show();
   return app.exec();
}