Add an option to share between TLWs

Task-number: QTBUG-41191
Change-Id: I510d1631926ed0d9e371703d22229aed92432aa6
Reviewed-by: Jørgen Lind <jorgen.lind@digia.com>

3 files changed, 26 insertions, 3 deletions

diff --git a/src/gui/kernel/qguiapplication.cpp b/src/gui/kernel/qguiapplication.cpp
index 2d7900b5d9..75311616a4 100644
--- a/src/gui/kernel/qguiapplication.cpp
+++ b/src/gui/kernel/qguiapplication.cpp
@@ -82,6 +82,7 @@
 #include <qpa/qwindowsysteminterface_p.h>
 #include "private/qwindow_p.h"
 #include "private/qcursor_p.h"
+#include "private/qopenglcontext_p.h"
 
 #include "private/qdnd_p.h"
 #include <qpa/qplatformthemefactory_p.h>
@@ -604,7 +605,8 @@ QGuiApplicationPrivate::QGuiApplicationPrivate(int &argc, char **argv, int flags
     : QCoreApplicationPrivate(argc, argv, flags),
       styleHints(0),
       inputMethod(0),
-      lastTouchType(QEvent::TouchEnd)
+      lastTouchType(QEvent::TouchEnd),
+      ownGlobalShareContext(false)
 {
     self = this;
     application_type = QCoreApplicationPrivate::Gui;
@@ -1313,6 +1315,17 @@ void QGuiApplicationPrivate::init()
     // trigger registering of animation interpolators
     qRegisterGuiGetInterpolator();
 
+    // set a global share context when enabled unless there is already one
+#ifndef QT_NO_OPENGL
+    if (qApp->testAttribute(Qt::AA_ShareOpenGLContexts) && !qt_gl_global_share_context()) {
+        QOpenGLContext *ctx = new QOpenGLContext;
+        ctx->setFormat(QSurfaceFormat::defaultFormat());
+        ctx->create();
+        qt_gl_set_global_share_context(ctx);
+        ownGlobalShareContext = true;
+    }
+#endif
+
     QWindowSystemInterfacePrivate::eventTime.start();
 
     is_app_running = true;
@@ -1374,6 +1387,13 @@ QGuiApplicationPrivate::~QGuiApplicationPrivate()
 
     QPixmapCache::clear();
 
+#ifndef QT_NO_OPENGL
+    if (ownGlobalShareContext) {
+        delete qt_gl_global_share_context();
+        qt_gl_set_global_share_context(0);
+    }
+#endif
+
     delete platform_theme;
     platform_theme = 0;
     delete platform_integration;
diff --git a/src/gui/kernel/qguiapplication_p.h b/src/gui/kernel/qguiapplication_p.h
index 5f9f6ad9f2..0fd4458083 100644
--- a/src/gui/kernel/qguiapplication_p.h
+++ b/src/gui/kernel/qguiapplication_p.h
@@ -307,6 +307,8 @@ private:
     static QTouchDevice *m_fakeTouchDevice;
     static int m_fakeMouseSourcePointId;
     QAtomicPointer<QDrawHelperGammaTables> m_gammaTables;
+
+    bool ownGlobalShareContext;
 };
 
 Q_GUI_EXPORT uint qHash(const QGuiApplicationPrivate::ActiveTouchPointsKey &k);
diff --git a/src/gui/kernel/qopenglcontext.cpp b/src/gui/kernel/qopenglcontext.cpp
index 6b2bb092b1..be8fa2415d 100644
--- a/src/gui/kernel/qopenglcontext.cpp
+++ b/src/gui/kernel/qopenglcontext.cpp
@@ -245,8 +245,9 @@ QMutex QOpenGLContextPrivate::makeCurrentTrackerMutex;
 /*!
     \internal
 
-    This function is used by the Qt WebEngine to set up context sharing
-    across multiple windows. Do not use it for any other purpose.
+    This function is used by Qt::AA_ShareOpenGLContexts and the Qt
+    WebEngine to set up context sharing across multiple windows. Do
+    not use it for any other purpose.
 
     Please maintain the binary compatibility of these functions.
 */