openglwindow.cpp

#include "openglwindow.h"

#include <QtCore/QCoreApplication>

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

//! [1]
OpenGLWindow::OpenGLWindow(QWindow *parent)
: QWindow(parent)
, m_update_pending(false)
, m_animating(false)
, m_context(0)
, m_paint_device(0)
{
setSurfaceType(QWindow::OpenGLSurface);
}

//! [1]

OpenGLWindow::~OpenGLWindow()
{
delete m_paint_device;
}
//! [2]
void OpenGLWindow::render(QPainter *painter)
{
Q_UNUSED(painter);
}

void OpenGLWindow::initialize()
{
}

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

glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

m_paint_device->setSize(size());

QPainter painter(m_paint_device);
render(&painter);
}
//! [2]

//! [3]
void OpenGLWindow::renderLater()
{
if (!m_update_pending) {
m_update_pending = true;
QCoreApplication::postEvent(this, new QEvent(QEvent::UpdateRequest));
}
}

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

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

if (isExposed())
renderNow();
}
//! [3]

//! [4]
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();
}
//! [4]

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

if (animating)
renderLater();
}