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();
}