Wt

#include <Wt/WApplication>

#include <Wt/WPaintedWidget>

#include <Wt/WPainter>

#include <Wt/WPainterPath>

using namespace Wt;

class SetWindowWidget : public WPaintedWidget {

public:

    SetWindowWidget(WContainerWidget* p = 0) :

        WPaintedWidget(p) {

        resize(500, 500);

    }

protected:

    void paintEvent(WPaintDevice* device) {

        Wt::WPainter painter(device);

        painter.setWindow(0, 0, 1, 1);

        painter.drawEllipse(0, 0, 1, 1);

        Wt::WPainterPath path;

        path.moveTo(0, 0);

        path.lineTo(1, 1);

        painter.drawPath(path);

    }

};

class SomePaintedApp : public WApplication {

public:

    SomePaintedApp(const WEnvironment& env):

        WApplication(env) {

        SetWindowWidget* png = new SetWindowWidget(root());

        png->setPreferredMethod(WPaintedWidget::PngImage);

        SetWindowWidget* normal = new SetWindowWidget(root());

    }

};

WApplication* createSomePaintedApp(const WEnvironment& env) {

    return new SomePaintedApp(env);

}

int main(int argc, char** argv) {

    return WRun(argc, argv, &createSomePaintedApp);

}