openglwindow.cpp Example File

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 #include "openglwindow.h"

 #include <QtCore/QCoreApplication>

 #include <QtGui/QOpenGLContext>
 #include <QtGui/QOpenGLPaintDevice>
 #include <QtGui/QPainter>

 OpenGLWindow::OpenGLWindow(QWindow *parent)
     : QWindow(parent)
     , m_animating(false)
     , m_context(0)
     , m_device(0)
 {
     setSurfaceType(QWindow::OpenGLSurface);
 }

 OpenGLWindow::~OpenGLWindow()
 {
     delete m_device;
 }
 void OpenGLWindow::render(QPainter *painter)
 {
     Q_UNUSED(painter);
 }

 void OpenGLWindow::initialize()
 {
 }

 void OpenGLWindow::render()
 {
     if (!m_device)
         m_device = new QOpenGLPaintDevice;

     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

     m_device->setSize(size() * devicePixelRatio());
     m_device->setDevicePixelRatio(devicePixelRatio());

     QPainter painter(m_device);
     render(&painter);
 }

 void OpenGLWindow::renderLater()
 {
     requestUpdate();
 }

 bool OpenGLWindow::event(QEvent *event)
 {
     switch (event->type()) {
     case QEvent::UpdateRequest:
         renderNow();
         return true;
     default:
         return QWindow::event(event);
     }
 }

 void OpenGLWindow::exposeEvent(QExposeEvent *event)
 {
     Q_UNUSED(event);

     if (isExposed())
         renderNow();
 }

 void OpenGLWindow::renderNow()
 {
     if (!isExposed())
         return;

     bool needsInitialize = false;

     if (!m_context) {
         m_context = new QOpenGLContext(this);
         m_context->setFormat(requestedFormat());
         m_context->create();

         needsInitialize = true;
     }

     m_context->makeCurrent(this);

     if (needsInitialize) {
         initializeOpenGLFunctions();
         initialize();
     }

     render();

     m_context->swapBuffers(this);

     if (m_animating)
         renderLater();
 }

 void OpenGLWindow::setAnimating(bool animating)
 {
     m_animating = animating;

     if (animating)
         renderLater();
 }