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());

      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();
  }