main.cpp Example File

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 #include <QApplication>
 #include <QDesktopWidget>
 #include <QSurfaceFormat>
 #include <QCommandLineParser>
 #include <QCommandLineOption>

 #include "glwidget.h"
 #include "mainwindow.h"

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

     QCoreApplication::setApplicationName("Qt Hello GL 2 Example");
     QCoreApplication::setOrganizationName("QtProject");
     QCoreApplication::setApplicationVersion(QT_VERSION_STR);
     QCommandLineParser parser;
     parser.setApplicationDescription(QCoreApplication::applicationName());
     parser.addHelpOption();
     parser.addVersionOption();
     QCommandLineOption multipleSampleOption("multisample", "Multisampling");
     parser.addOption(multipleSampleOption);
     QCommandLineOption coreProfileOption("coreprofile", "Use core profile");
     parser.addOption(coreProfileOption);
     QCommandLineOption transparentOption("transparent", "Transparent window");
     parser.addOption(transparentOption);

     parser.process(app);

     QSurfaceFormat fmt;
     fmt.setDepthBufferSize(24);
     if (parser.isSet(multipleSampleOption))
         fmt.setSamples(4);
     if (parser.isSet(coreProfileOption)) {
         fmt.setVersion(3, 2);
         fmt.setProfile(QSurfaceFormat::CoreProfile);
     }
     QSurfaceFormat::setDefaultFormat(fmt);

     MainWindow mainWindow;

     GLWidget::setTransparent(parser.isSet(transparentOption));
     if (GLWidget::isTransparent()) {
         mainWindow.setAttribute(Qt::WA_TranslucentBackground);
         mainWindow.setAttribute(Qt::WA_NoSystemBackground, false);
     }
     mainWindow.resize(mainWindow.sizeHint());
     int desktopArea = QApplication::desktop()->width() *
                      QApplication::desktop()->height();
     int widgetArea = mainWindow.width() * mainWindow.height();
     if (((float)widgetArea / (float)desktopArea) < 0.75f)
         mainWindow.show();
     else
         mainWindow.showMaximized();
     return app.exec();
 }