Add Q3DSSurfaceViewer API

Same disclaimer as for widgets, rendering is not perfect yet.

Offscreen readback is broken for reasons not known. (QT3DS-1042)

When rendering offscreen (and then reading back to generate images for
example), the global animation time cannot be controlled yet.
(to be handled in QT3DS-1041)

As a bonus, Qt 3D apparently does not like when the event loop is never
pupmped (because the application returns right away from main()) and
tends to deadlock upon cleanup. Worked around with a processEvents in
the example, needs a better solution later.

The API is revised somewhat when compared to 3DS1. Fixed frameUpdate
naming, now uses normal Qt patterns for create-destroy, etc.

Change-Id: Iee0c39483831b68fbc1889922d54b3cc5e8726e2
Reviewed-by: Andy Nichols <andy.nichols@qt.io>

11 files changed, 618 insertions, 0 deletions

diff --git a/examples/3dstudioruntime2/3dstudioruntime2.pro b/examples/3dstudioruntime2/3dstudioruntime2.pro
index 267749d..9f1b2c5 100644
--- a/examples/3dstudioruntime2/3dstudioruntime2.pro
+++ b/examples/3dstudioruntime2/3dstudioruntime2.pro
@@ -1,5 +1,9 @@
 TEMPLATE = subdirs
 
+SUBDIRS += \
+    simplewindow \
+    simpleoffscreen
+
 qtHaveModule(quick) {
     SUBDIRS += simpleqml
 }
diff --git a/examples/3dstudioruntime2/simpleoffscreen/main.cpp b/examples/3dstudioruntime2/simpleoffscreen/main.cpp
new file mode 100644
index 0000000..b7594dc
--- /dev/null
+++ b/examples/3dstudioruntime2/simpleoffscreen/main.cpp
@@ -0,0 +1,118 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt 3D Studio.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <q3dsruntimeglobal.h>
+#include <Q3DSSurfaceViewer>
+#include <Q3DSPresentation>
+#include <QGuiApplication>
+#include <QOffscreenSurface>
+#include <QOpenGLContext>
+#include <QOpenGLFramebufferObject>
+#include <QThread>
+
+int main(int argc, char *argv[])
+{
+    QGuiApplication app(argc, argv);
+    QSurfaceFormat::setDefaultFormat(Q3DS::surfaceFormat());
+
+    QOpenGLContext context;
+    if (!context.create())
+        qFatal("Failed to create OpenGL context");
+
+    // Must have a "surface". Depending on the platform this may be a small
+    // window, pbuffer surface, or even nothing (in case surfaceless contexts are
+    // supported) under the hood.
+    QOffscreenSurface surface;
+    surface.create();
+
+    if (!context.makeCurrent(&surface))
+        qFatal("makeCurrent failed");
+
+    const QSize size(1280, 800);
+    QOpenGLFramebufferObject fbo(size, QOpenGLFramebufferObject::CombinedDepthStencil);
+
+    Q3DSSurfaceViewer viewer;
+    viewer.presentation()->setSource(QUrl(QStringLiteral("qrc:/barrel.uip")));
+
+    // Will call update() manually when a new frame is wanted.
+    viewer.setUpdateInterval(-1);
+
+    // Automatic sizing must be turned off.
+    viewer.setAutoSize(false);
+
+    // Provide the render target size instead.
+    viewer.setSize(size);
+
+    if (!viewer.create(&surface, &context, fbo.handle()))
+        qFatal("Initialization failed");
+
+    // Render a few frames, read them back, and save into png files.
+    for (int frame = 1; frame <= 20; ++frame) {
+        // Render the next frame.
+        viewer.update();
+
+        // Write it to a file.
+        const QString fn = QString(QLatin1String("output_%1.png")).arg(frame);
+        fbo.toImage().save(fn);
+
+        qDebug("Rendered and saved frame %d to %s", frame, qPrintable(fn));
+
+        // ### hack until QT3DS-1041 is in place
+        QThread::msleep(10);
+    }
+
+    // Now one could do the following to generate a 60 fps video from these frames:
+    //   ffmpeg -r 60 -f image2 -s 1280x800 -i output_%d.png -vcodec libx264 -crf 25 -pix_fmt yuv420p output.mp4
+
+    // ### this should not be needed. Qt3D should be able to shut down without it.
+    QGuiApplication::processEvents();
+
+    return 0;
+}
diff --git a/examples/3dstudioruntime2/simpleoffscreen/simpleoffscreen.pro b/examples/3dstudioruntime2/simpleoffscreen/simpleoffscreen.pro
new file mode 100644
index 0000000..e4751db
--- /dev/null
+++ b/examples/3dstudioruntime2/simpleoffscreen/simpleoffscreen.pro
@@ -0,0 +1,11 @@
+TEMPLATE = app
+
+QT += 3dstudioruntime2
+
+SOURCES += \
+    main.cpp
+
+RESOURCES += simpleoffscreen.qrc
+
+target.path = $$[QT_INSTALL_EXAMPLES]/3dstudioruntime2/$$TARGET
+INSTALLS += target
diff --git a/examples/3dstudioruntime2/simpleoffscreen/simpleoffscreen.qrc b/examples/3dstudioruntime2/simpleoffscreen/simpleoffscreen.qrc
new file mode 100644
index 0000000..4558e47
--- /dev/null
+++ b/examples/3dstudioruntime2/simpleoffscreen/simpleoffscreen.qrc
@@ -0,0 +1,11 @@
+<RCC>
+    <qresource prefix="/">
+        <file alias="barrel.uip">../simpleqml/presentation/barrel.uip</file>
+        <file alias="barrel/meshes/Barrel.mesh">../simpleqml/presentation/barrel/meshes/Barrel.mesh</file>
+        <file alias="fonts/Arimo-Regular.ttf">../simpleqml/presentation/fonts/Arimo-Regular.ttf</file>
+        <file alias="maps/barrel_barrel_Diffuse.png">../simpleqml/presentation/maps/barrel_barrel_Diffuse.png</file>
+        <file alias="maps/barrel_barrel_Emissive.png">../simpleqml/presentation/maps/barrel_barrel_Emissive.png</file>
+        <file alias="maps/barrel_barrel_Normal.png">../simpleqml/presentation/maps/barrel_barrel_Normal.png</file>
+        <file alias="maps/barrel_barrel_Specular.png">../simpleqml/presentation/maps/barrel_barrel_Specular.png</file>
+    </qresource>
+</RCC>
diff --git a/examples/3dstudioruntime2/simplewindow/main.cpp b/examples/3dstudioruntime2/simplewindow/main.cpp
new file mode 100644
index 0000000..c335b96
--- /dev/null
+++ b/examples/3dstudioruntime2/simplewindow/main.cpp
@@ -0,0 +1,102 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt 3D Studio.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QGuiApplication>
+#include <QCommandLineParser>
+#include <QDebug>
+
+#include <q3dsruntimeglobal.h>
+#include <Q3DSSurfaceViewer>
+#include <Q3DSPresentation>
+
+#include "window_manualupdate.h"
+#include "window_autoupdate.h"
+
+int main(int argc, char *argv[])
+{
+    QGuiApplication app(argc, argv);
+    QSurfaceFormat::setDefaultFormat(Q3DS::surfaceFormat());
+
+    QCommandLineParser parser;
+    QCommandLineOption multiWindowOption("multi", "Multiple windows");
+    parser.addOption(multiWindowOption);
+    parser.process(app);
+
+    ManualUpdateWindow w;
+    w.setTitle(QLatin1String("Qt 3D Studio plain QWindow Example"));
+    Q3DSSurfaceViewer viewer;
+    QObject::connect(&viewer, &Q3DSSurfaceViewer::errorChanged, &viewer, [&viewer] {
+        const QString msg = viewer.error();
+        if (!msg.isEmpty())
+            qWarning() << msg;
+    });
+    viewer.presentation()->setSource(QUrl(QLatin1String("qrc:/barrel.uip")));
+    viewer.create(&w, w.context());
+    w.setViewer(&viewer);
+    w.resize(1024, 768);
+    w.show();
+
+    QScopedPointer<AutoUpdateWindow> w2;
+    QScopedPointer<Q3DSSurfaceViewer> viewer2;
+    if (parser.isSet(multiWindowOption)) {
+        w2.reset(new AutoUpdateWindow);
+        viewer2.reset(new Q3DSSurfaceViewer);
+        viewer2->presentation()->setSource(QUrl(QLatin1String("qrc:/barrel.uip")));
+        // change from the default -1 (auto-update disabled) to an interval of
+        // 0 since AutoUpdateWindow does not do anything on its own that would
+        // lead to calling update()
+        viewer2->setUpdateInterval(0);
+        viewer2->create(w2.data(), w2->context());
+        w2->resize(800, 600);
+        w2->show();
+    }
+
+    return app.exec();
+}
diff --git a/examples/3dstudioruntime2/simplewindow/simplewindow.pro b/examples/3dstudioruntime2/simplewindow/simplewindow.pro
new file mode 100644
index 0000000..cf4e8ce
--- /dev/null
+++ b/examples/3dstudioruntime2/simplewindow/simplewindow.pro
@@ -0,0 +1,17 @@
+TEMPLATE = app
+
+QT += 3dstudioruntime2
+
+SOURCES += \
+    main.cpp \
+    window_manualupdate.cpp \
+    window_autoupdate.cpp
+
+HEADERS += \
+    window_manualupdate.h \
+    window_autoupdate.h
+
+RESOURCES += simplewindow.qrc
+
+target.path = $$[QT_INSTALL_EXAMPLES]/3dstudioruntime2/$$TARGET
+INSTALLS += target
diff --git a/examples/3dstudioruntime2/simplewindow/simplewindow.qrc b/examples/3dstudioruntime2/simplewindow/simplewindow.qrc
new file mode 100644
index 0000000..4558e47
--- /dev/null
+++ b/examples/3dstudioruntime2/simplewindow/simplewindow.qrc
@@ -0,0 +1,11 @@
+<RCC>
+    <qresource prefix="/">
+        <file alias="barrel.uip">../simpleqml/presentation/barrel.uip</file>
+        <file alias="barrel/meshes/Barrel.mesh">../simpleqml/presentation/barrel/meshes/Barrel.mesh</file>
+        <file alias="fonts/Arimo-Regular.ttf">../simpleqml/presentation/fonts/Arimo-Regular.ttf</file>
+        <file alias="maps/barrel_barrel_Diffuse.png">../simpleqml/presentation/maps/barrel_barrel_Diffuse.png</file>
+        <file alias="maps/barrel_barrel_Emissive.png">../simpleqml/presentation/maps/barrel_barrel_Emissive.png</file>
+        <file alias="maps/barrel_barrel_Normal.png">../simpleqml/presentation/maps/barrel_barrel_Normal.png</file>
+        <file alias="maps/barrel_barrel_Specular.png">../simpleqml/presentation/maps/barrel_barrel_Specular.png</file>
+    </qresource>
+</RCC>
diff --git a/examples/3dstudioruntime2/simplewindow/window_autoupdate.cpp b/examples/3dstudioruntime2/simplewindow/window_autoupdate.cpp
new file mode 100644
index 0000000..927f064
--- /dev/null
+++ b/examples/3dstudioruntime2/simplewindow/window_autoupdate.cpp
@@ -0,0 +1,64 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt 3D Studio.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "window_autoupdate.h"
+#include <QOpenGLContext>
+
+// Here the window implementation relies on rendering happening automatically
+// with some interval whenever isExposed()==true.
+
+// No event handlers in this version, so the 3D Studio scene is non-interactive.
+
+AutoUpdateWindow::AutoUpdateWindow()
+{
+    setSurfaceType(QSurface::OpenGLSurface);
+    m_context = new QOpenGLContext(this);
+    m_context->create();
+}
diff --git a/examples/3dstudioruntime2/simplewindow/window_autoupdate.h b/examples/3dstudioruntime2/simplewindow/window_autoupdate.h
new file mode 100644
index 0000000..7820cd8
--- /dev/null
+++ b/examples/3dstudioruntime2/simplewindow/window_autoupdate.h
@@ -0,0 +1,70 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt 3D Studio.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef WINDOW_AUTOUPDATE_H
+#define WINDOW_AUTOUPDATE_H
+
+#include <QWindow>
+
+QT_BEGIN_NAMESPACE
+class QOpenGLContext;
+QT_END_NAMESPACE
+
+class AutoUpdateWindow : public QWindow
+{
+public:
+    AutoUpdateWindow();
+    QOpenGLContext *context() const { return m_context; }
+
+private:
+    QOpenGLContext *m_context;
+};
+
+#endif
diff --git a/examples/3dstudioruntime2/simplewindow/window_manualupdate.cpp b/examples/3dstudioruntime2/simplewindow/window_manualupdate.cpp
new file mode 100644
index 0000000..d796148
--- /dev/null
+++ b/examples/3dstudioruntime2/simplewindow/window_manualupdate.cpp
@@ -0,0 +1,123 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt 3D Studio.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "window_manualupdate.h"
+#include <QOpenGLContext>
+#include <Q3DSSurfaceViewer>
+#include <Q3DSPresentation>
+
+// Here the window implementation drives rendering by manually calling
+// Q3DSSurfaceViewer::update() as seen fit.
+
+// It also relies on the default of autoSize==true (meaning the rendering
+// is automatically following the QWindow size).
+
+ManualUpdateWindow::ManualUpdateWindow()
+{
+    setSurfaceType(QSurface::OpenGLSurface);
+    m_context = new QOpenGLContext(this);
+    m_context->create();
+}
+
+void ManualUpdateWindow::update()
+{
+    if (isExposed() && m_viewer) {
+        m_viewer->update();
+        // render continuously
+        requestUpdate();
+    }
+}
+
+bool ManualUpdateWindow::event(QEvent *e)
+{
+    if (e->type() == QEvent::Expose || e->type() == QEvent::UpdateRequest)
+        update();
+
+    return QWindow::event(e);
+}
+
+void ManualUpdateWindow::keyPressEvent(QKeyEvent *e)
+{
+    m_viewer->presentation()->keyPressEvent(e);
+}
+
+void ManualUpdateWindow::keyReleaseEvent(QKeyEvent *e)
+{
+    m_viewer->presentation()->keyReleaseEvent(e);
+}
+
+void ManualUpdateWindow::mousePressEvent(QMouseEvent *e)
+{
+    m_viewer->presentation()->mousePressEvent(e);
+}
+
+void ManualUpdateWindow::mouseMoveEvent(QMouseEvent *e)
+{
+    // Moves must be forwarded even when no button is down; the
+    // default QWindow behavior is just what we need in this respect.
+    m_viewer->presentation()->mouseMoveEvent(e);
+}
+
+void ManualUpdateWindow::mouseReleaseEvent(QMouseEvent *e)
+{
+    m_viewer->presentation()->mouseReleaseEvent(e);
+}
+
+void ManualUpdateWindow::mouseDoubleClickEvent(QMouseEvent *e)
+{
+    m_viewer->presentation()->mouseDoubleClickEvent(e);
+}
+
+#if QT_CONFIG(wheelevent)
+void ManualUpdateWindow::wheelEvent(QWheelEvent *e)
+{
+    m_viewer->presentation()->wheelEvent(e);
+}
+#endif
diff --git a/examples/3dstudioruntime2/simplewindow/window_manualupdate.h b/examples/3dstudioruntime2/simplewindow/window_manualupdate.h
new file mode 100644
index 0000000..7f3cb58
--- /dev/null
+++ b/examples/3dstudioruntime2/simplewindow/window_manualupdate.h
@@ -0,0 +1,87 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt 3D Studio.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef WINDOW_MANUALUPDATE_H
+#define WINDOW_MANUALUPDATE_H
+
+#include <QWindow>
+
+QT_BEGIN_NAMESPACE
+class Q3DSSurfaceViewer;
+class QOpenGLContext;
+QT_END_NAMESPACE
+
+class ManualUpdateWindow : public QWindow
+{
+public:
+    ManualUpdateWindow();
+    void setViewer(Q3DSSurfaceViewer *viewer) { m_viewer = viewer; }
+    QOpenGLContext *context() const { return m_context; }
+
+protected:
+    bool event(QEvent *) override;
+    void update();
+
+    void keyPressEvent(QKeyEvent *) override;
+    void keyReleaseEvent(QKeyEvent *) override;
+    void mousePressEvent(QMouseEvent *) override;
+    void mouseMoveEvent(QMouseEvent *) override;
+    void mouseReleaseEvent(QMouseEvent *) override;
+    void mouseDoubleClickEvent(QMouseEvent *) override;
+#if QT_CONFIG(wheelevent)
+    void wheelEvent(QWheelEvent *) override;
+#endif
+
+private:
+    Q3DSSurfaceViewer *m_viewer = nullptr;
+    QOpenGLContext *m_context;
+};
+
+#endif