QGraphicsView QSvgRenderer and OpenGl

Hey Guys,

basically i want to render multiple layered Svg on the Graphics card, in 20-50ms update rate.
For Testing and understanding this i wrote some Code.
It works, but not as i expexcted.
It looks not really antialized. Also it should be resizable at runtime.

Header of my Widgets i want to place inside the QGraphics View

Code:

---

#ifndef SVGWIDGET_H_
#define SVGWIDGET_H_
 
#include <qwidget.h>
#include <qsvgrenderer.h>
 
/*!
 * @brief This class represents a little extension of the QWidget to display a svg as a backgroundimage.
 */
class SvgWidget : public QWidget
{
public:
  /*!
   *Constructor with given parent Widget
   * @param parent is the parent widget
   */
  SvgWidget(QWidget * parent);
  ~SvgWidget();
 
  /*!
   * Sets the background to be displayed and resizes the widget to the
   * background's size.
   * repaints the widget if background is changed
   * @param backgroundPath the path to the svg for the background
   */
  void
  setUpBackgroundSvg(QString backgroundPath);
 
protected:
  /*!
   * Paints the background of the widget.
   * @param pe
   */
  void
  paintEvent(QPaintEvent *pe);
 
private:
  /*!
   * Renderer for the background
   */
  QSvgRenderer background_;
};
 
#endif /* SVGWIDGET_H_ */

---

source file of my little SvgWidget

Code:

---

#include <SvgWidget.h>
#include <qpainter.h>
#include <qlayout.h>
 
SvgWidget::SvgWidget(QWidget * parent) :
    QWidget(parent),background_(this)
{
}
 
SvgWidget::~SvgWidget()
{
}
 
void
SvgWidget::setUpBackgroundSvg(QString backgroundPath)
{
  background_.load(backgroundPath);
 
  this->resize(background_.defaultSize());
  repaint();
}
 
void
SvgWidget::paintEvent(QPaintEvent *pe)
{
  if (background_.isValid())
    {
      QPainter painter(this);
      background_.render(&painter);
    }
}

---

Code:

---

#ifndef MYVIEW_H_
#define MYVIEW_H_
 
#include <qgraphicsview.h>
#include "SvgWidget.h"
 
class MyView : public QGraphicsView
{
  Q_OBJECT
  SvgWidget* widget;
  QTimer* timer_;
public:
  MyView(QWidget* parent = 0);
  virtual
  ~MyView();
};
 
#endif /* MYVIEW_H_ */

---

Code:

---

#include "MyView.h"
#include <QGLWidget>
#include <qtimer.h>
 
MyView::MyView(QWidget* parent) :
    QGraphicsView(parent)
{
  setScene(new QGraphicsScene(this));
 
  widget = new SvgWidget(0);
  widget->setUpBackgroundSvg(":/images/some.svg");
  //some more layers will be set up here
  scene()->addWidget(widget);       //from here
  setViewport(
      new QGLWidget(QGLFormat(QGL::SampleBuffers | QGL::DirectRendering)));
  setViewportUpdateMode(QGraphicsView::FullViewportUpdate);
  update();                                      //to here 
  // if the code above is disabled, it looks better but is not rendered on the cpu right?
  timer_ = new QTimer(this);
  timer_->setInterval(20);
  connect(timer_, SIGNAL(timeout()), this, SLOT(repaint()));
  timer_->start();
}
 
MyView::~MyView()
{
}

---

main.cpp

Code:

---

#include <qapplication.h>
#include "MyView.h"
 
 
int
main(int argc, char *argv[])
{
 
  QApplication app(argc, argv);
  MyView myView(0);
  myView.repaint();
  myView.show();
  return app.exec();
 
}

---

I'm very Happy for all suggestions how to draw a Svg on the GPU.

Thank You!