[SOLVED] How do I set the QTOpenGLContext of a qml window before I run it.

Martell Malone

Hi Guys,

I have the following code.

@
QQmlEngine engine;
QQmlComponent component(&engine);
component.loadUrl(QUrl("qrc:/qml/main.qml"));
if ( !component.isReady() ) {
qWarning("%s", qPrintable(component.errorString()));
return -1;
}

QObject *topLevel = component.create();
QQuickWindow *window = qobject_cast<QQuickWindow *>(topLevel);

if ( !window ) {
    qWarning("Error: Your root item has to be a Window.");
    return -1;
}
window->show();

@

How do I set the context of the QWindow to a custom QOpenGLContext?

I tried to Extend QWindow via EditorWindow
but I get the error Your root item has to be a Window.

I have seen this but cant quite implement it.
http://qt-project.org/forums/viewthread/25268/

ZapB

You don't set the context itself. Instead, request a custom context that matches what you wish by creating a QSurfaceFormat, setting options on it as needed and calling setFormat() in the ctor of a QQuickWindow subclass.

Martell Malone

Ok so now I have this.

@
#ifndef MyWindow_h
#define MyWindow_h

#include <QtQuick/QQuickWindow>

class MyWindow : public QQuickWindow {
Q_OBJECT

public:
MyWindow(QWindow* parent = 0);

};

#endif
@

and

@

#include "MyWindow.h"

#include <QtCore/QTimer>

MyWindow::MyWindow(QWindow* parent)
: QQuickWindow(parent)
{

QSurfaceFormat m_format;
m_format.setMajorVersion(2);
m_format.setMinorVersion(0);

m_format.setDepthBufferSize(24);
m_format.setAlphaBufferSize(8);
m_format.setRedBufferSize(8);
m_format.setGreenBufferSize(8);
m_format.setBlueBufferSize(8);
m_format.setSamples(4);
m_format.setStencilBufferSize(8);
m_format.setOption(QSurfaceFormat::StereoBuffers);

//really need this?
setFormat(m_format);

QOpenGLContext m_context(this)
m_context.setFormat(m_format);

if (!m_context.create())
    qFatal("Cannot create the requested OpenGL context!");
    m_context.makeCurrent(this);

}
@

How do I get this as my root window for the qml component ?

Martell Malone

Hi guys think I have solved this for anyone else looking to do it.

@

QGuiApplication app( argc, argv );

MyWindow window;
QQmlEngine engine;
QQmlComponent component(&engine, QUrl::fromLocalFile&#40;QLatin1String("qml/main.qml"&#41;&#41;);

QQuickItem *item = qobject_cast<QQuickItem*>(component.create());
item->setParentItem(window.contentItem());
qDebug() << item;

window.show();

return app.exec&#40;&#41;

@

you cast back to a qquickitem and set our window as the parent like so.

Thanks again zapB