3 files changed, 54 insertions, 10 deletions

diff --git a/examples/quick/rendercontrol/main.cpp b/examples/quick/rendercontrol/main.cpp
index c9c7eeb525..71903045cc 100644
--- a/examples/quick/rendercontrol/main.cpp
+++ b/examples/quick/rendercontrol/main.cpp
@@ -49,6 +49,8 @@
 ****************************************************************************/
 
 #include <QGuiApplication>
+#include <QCommandLineParser>
+#include <QCommandLineOption>
 #include "window_singlethreaded.h"
 #include "window_multithreaded.h"
 
@@ -56,8 +58,20 @@ int main(int argc, char **argv)
 {
     QGuiApplication app(argc, argv);
 
+    QCoreApplication::setApplicationName("Qt Render Control Example");
+    QCoreApplication::setOrganizationName("QtProject");
+    QCoreApplication::setApplicationVersion(QT_VERSION_STR);
+    QCommandLineParser parser;
+    parser.setApplicationDescription(QCoreApplication::applicationName());
+    parser.addHelpOption();
+    parser.addVersionOption();
+    QCommandLineOption threadedOption("threaded", "Threaded Rendering");
+    parser.addOption(threadedOption);
+
+    parser.process(app);
+
     QScopedPointer<QWindow> window;
-    if (QCoreApplication::arguments().contains(QLatin1String("--threaded"))) {
+    if (parser.isSet(threadedOption)) {
         qWarning("Using separate Qt Quick render thread");
         window.reset(new WindowMultiThreaded);
     } else {
diff --git a/examples/quick/rendercontrol/window_singlethreaded.cpp b/examples/quick/rendercontrol/window_singlethreaded.cpp
index 1dee8b9f74..7a7b4f57e9 100644
--- a/examples/quick/rendercontrol/window_singlethreaded.cpp
+++ b/examples/quick/rendercontrol/window_singlethreaded.cpp
@@ -92,6 +92,10 @@ WindowSingleThreaded::WindowSingleThreaded()
 {
     setSurfaceType(QSurface::OpenGLSurface);
 
+    // The rendercontrol does not necessarily need an FBO. Demonstrate this
+    // when requested.
+    m_onscreen = QCoreApplication::arguments().contains(QStringLiteral("--onscreen"));
+
     QSurfaceFormat format;
     // Qt Quick may need a depth and stencil buffer. Always make sure these are available.
     format.setDepthBufferSize(16);
@@ -174,8 +178,14 @@ void WindowSingleThreaded::createFbo()
     // The scene graph has been initialized. It is now time to create an FBO and associate
     // it with the QQuickWindow.
     m_dpr = devicePixelRatio();
-    m_fbo = new QOpenGLFramebufferObject(size() * m_dpr, QOpenGLFramebufferObject::CombinedDepthStencil);
-    m_quickWindow->setRenderTarget(m_fbo);
+    if (!m_onscreen) {
+        m_fbo = new QOpenGLFramebufferObject(size() * m_dpr, QOpenGLFramebufferObject::CombinedDepthStencil);
+        m_quickWindow->setRenderTarget(m_fbo);
+    } else {
+        // Special case: No FBO. Render directly to the window's default framebuffer.
+        m_onscreenSize = size() * m_dpr;
+        m_quickWindow->setRenderTarget(0, m_onscreenSize);
+    }
 }
 
 void WindowSingleThreaded::destroyFbo()
@@ -186,7 +196,10 @@ void WindowSingleThreaded::destroyFbo()
 
 void WindowSingleThreaded::render()
 {
-    if (!m_context->makeCurrent(m_offscreenSurface))
+    QSurface *surface = m_offscreenSurface;
+    if (m_onscreen)
+        surface = this;
+    if (!m_context->makeCurrent(surface))
         return;
 
     // Polish, synchronize and render the next frame (into our fbo).  In this example
@@ -205,7 +218,10 @@ void WindowSingleThreaded::render()
     m_quickReady = true;
 
     // Get something onto the screen.
-    m_cubeRenderer->render(this, m_context, m_quickReady ? m_fbo->texture() : 0);
+    if (!m_onscreen)
+        m_cubeRenderer->render(this, m_context, m_quickReady ? m_fbo->texture() : 0);
+    else
+        m_context->swapBuffers(this);
 }
 
 void WindowSingleThreaded::requestUpdate()
@@ -247,7 +263,10 @@ void WindowSingleThreaded::run()
     updateSizes();
 
     // Initialize the render control and our OpenGL resources.
-    m_context->makeCurrent(m_offscreenSurface);
+    QSurface *surface = m_offscreenSurface;
+    if (m_onscreen)
+        surface = this;
+    m_context->makeCurrent(surface);
     m_renderControl->initialize(m_context);
     m_quickInitialized = true;
 }
@@ -276,7 +295,8 @@ void WindowSingleThreaded::exposeEvent(QExposeEvent *)
 {
     if (isExposed()) {
         if (!m_quickInitialized) {
-            m_cubeRenderer->render(this, m_context, m_quickReady ? m_fbo->texture() : 0);
+            if (!m_onscreen)
+                m_cubeRenderer->render(this, m_context, m_quickReady ? m_fbo->texture() : 0);
             startQuick(QStringLiteral("qrc:/rendercontrol/demo.qml"));
         }
     }
@@ -284,7 +304,10 @@ void WindowSingleThreaded::exposeEvent(QExposeEvent *)
 
 void WindowSingleThreaded::resizeFbo()
 {
-    if (m_rootItem && m_context->makeCurrent(m_offscreenSurface)) {
+    QSurface *surface = m_offscreenSurface;
+    if (m_onscreen)
+        surface = this;
+    if (m_rootItem && m_context->makeCurrent(surface)) {
         delete m_fbo;
         createFbo();
         m_context->doneCurrent();
@@ -297,8 +320,13 @@ void WindowSingleThreaded::resizeEvent(QResizeEvent *)
 {
     // If this is a resize after the scene is up and running, recreate the fbo and the
     // Quick item and scene.
-    if (m_fbo && m_fbo->size() != size() * devicePixelRatio())
-        resizeFbo();
+    if (!m_onscreen) {
+        if (m_fbo && m_fbo->size() != size() * devicePixelRatio())
+            resizeFbo();
+    } else {
+        if (m_onscreenSize != size() * devicePixelRatio())
+            resizeFbo();
+    }
 }
 
 void WindowSingleThreaded::handleScreenChange()
diff --git a/examples/quick/rendercontrol/window_singlethreaded.h b/examples/quick/rendercontrol/window_singlethreaded.h
index dadd9daf7e..8ec64eb6f5 100644
--- a/examples/quick/rendercontrol/window_singlethreaded.h
+++ b/examples/quick/rendercontrol/window_singlethreaded.h
@@ -107,6 +107,8 @@ private:
     QTimer m_updateTimer;
     CubeRenderer *m_cubeRenderer;
     qreal m_dpr;
+    bool m_onscreen;
+    QSize m_onscreenSize;
 };
 
 #endif