Added private API for enabling sharing between the QQuickwindow instances.

This API is primarily a hook which is needed by the Qt WebEngine to
set up sharing with the scene graph's OpenGL contexts.

Change-Id: I5bb03abd9ab99f502db8e413fe838a8b30365b8d
Reviewed-by: Jocelyn Turcotte <jocelyn.turcotte@digia.com>

5 files changed, 27 insertions, 0 deletions

diff --git a/src/quick/scenegraph/qsgcontext.cpp b/src/quick/scenegraph/qsgcontext.cpp
index 4fbefb37d8..c6dbf350b6 100644
--- a/src/quick/scenegraph/qsgcontext.cpp
+++ b/src/quick/scenegraph/qsgcontext.cpp
@@ -117,8 +117,12 @@ public:
     QSGContext::AntialiasingMethod antialiasingMethod;
     bool distanceFieldDisabled;
     QSGDistanceFieldGlyphNode::AntialiasingMode distanceFieldAntialiasing;
+
+    static QOpenGLContext *sharedOpenGLContext;
 };
 
+QOpenGLContext *QSGContextPrivate::sharedOpenGLContext = 0;
+
 class QSGTextureCleanupEvent : public QEvent
 {
 public:
@@ -170,6 +174,20 @@ QSGContext::~QSGContext()
 {
 }
 
+/*!
+ * This function is used by the Qt WebEngine to set up context sharing
+ * across multiple windows. Do not use it for any other purpose.
+ */
+void QSGContext::setSharedOpenGLContext(QOpenGLContext *context)
+{
+    QSGContextPrivate::sharedOpenGLContext = context;
+}
+
+QOpenGLContext *QSGContext::sharedOpenGLContext()
+{
+    return QSGContextPrivate::sharedOpenGLContext;
+}
+
 void QSGContext::renderContextInitialized(QSGRenderContext *renderContext)
 {
     Q_D(QSGContext);
diff --git a/src/quick/scenegraph/qsgcontext_p.h b/src/quick/scenegraph/qsgcontext_p.h
index 08fafb0713..270f108373 100644
--- a/src/quick/scenegraph/qsgcontext_p.h
+++ b/src/quick/scenegraph/qsgcontext_p.h
@@ -162,6 +162,9 @@ public:
     virtual QSize minimumFBOSize() const;
     virtual QSurfaceFormat defaultSurfaceFormat() const;
 
+    static void setSharedOpenGLContext(QOpenGLContext *context);
+    static QOpenGLContext *sharedOpenGLContext();
+
     void setDistanceFieldEnabled(bool enabled);
     bool isDistanceFieldEnabled() const;
 
diff --git a/src/quick/scenegraph/qsgrenderloop.cpp b/src/quick/scenegraph/qsgrenderloop.cpp
index fc1e98d87f..f294cb4a2d 100644
--- a/src/quick/scenegraph/qsgrenderloop.cpp
+++ b/src/quick/scenegraph/qsgrenderloop.cpp
@@ -264,6 +264,8 @@ void QSGGuiThreadRenderLoop::renderWindow(QQuickWindow *window)
     if (!gl) {
         gl = new QOpenGLContext();
         gl->setFormat(window->requestedFormat());
+        if (QSGContext::sharedOpenGLContext())
+            gl->setShareContext(QSGContext::sharedOpenGLContext());
         if (!gl->create()) {
             delete gl;
             gl = 0;
diff --git a/src/quick/scenegraph/qsgthreadedrenderloop.cpp b/src/quick/scenegraph/qsgthreadedrenderloop.cpp
index bb0bd67d6b..42c7c9c0ba 100644
--- a/src/quick/scenegraph/qsgthreadedrenderloop.cpp
+++ b/src/quick/scenegraph/qsgthreadedrenderloop.cpp
@@ -889,6 +889,8 @@ void QSGThreadedRenderLoop::handleExposure(Window *w)
 
         if (!w->thread->gl) {
             w->thread->gl = new QOpenGLContext();
+            if (QSGContext::sharedOpenGLContext())
+                w->thread->gl->setShareContext(QSGContext::sharedOpenGLContext());
             w->thread->gl->setFormat(w->window->requestedFormat());
             if (!w->thread->gl->create()) {
                 delete w->thread->gl;
diff --git a/src/quick/scenegraph/qsgwindowsrenderloop.cpp b/src/quick/scenegraph/qsgwindowsrenderloop.cpp
index f1d09c3785..d5d12bd138 100644
--- a/src/quick/scenegraph/qsgwindowsrenderloop.cpp
+++ b/src/quick/scenegraph/qsgwindowsrenderloop.cpp
@@ -178,6 +178,8 @@ void QSGWindowsRenderLoop::show(QQuickWindow *window)
         RLDEBUG(" - creating GL context");
         m_gl = new QOpenGLContext();
         m_gl->setFormat(window->requestedFormat());
+        if (QSGContext::sharedOpenGLContext())
+            m_gl->setShareContext(QSGContext::sharedOpenGLContext());
         m_gl->create();
         QSG_RENDER_TIMING_SAMPLE(time_created);
         RLDEBUG(" - making current");