Added cast to qreal, avoiding ftbfs due to issue #758 More explanation here https://wiki.debian.org/ArmEabiFixes And on qt-project.org reference website: "Typedef for double on all platforms except for those using CPUs with ARM architectures. On ARM-based platforms, qreal is a typedef for float for performance reasons."

#include <QtGui/QApplication>
#include "mainwindow.h"

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();
    return a.exec();
}