Take ShareOpenGLContexts into account in QOpenGLWindow

While the attribute was originally intended for widgets (QOpenGLWidget,
QQuickWidget) only, we need a way to get multiple QOpenGLWindow instances
whose contexts share with each other.

Change-Id: Ib983c9c2815b0a3911bc504ffad8d8dddad192aa
Reviewed-by: Jørgen Lind <jorgen.lind@theqtcompany.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/src/gui/kernel/qopenglwindow.cpp b/src/gui/kernel/qopenglwindow.cpp
index 158fb248dc..c37974c429 100644
--- a/src/gui/kernel/qopenglwindow.cpp
+++ b/src/gui/kernel/qopenglwindow.cpp
@@ -38,6 +38,7 @@
 #include <QtGui/QOpenGLFunctions>
 #include <QtGui/private/qopengltextureblitter_p.h>
 #include <QtGui/private/qopenglextensions_p.h>
+#include <QtGui/private/qopenglcontext_p.h>
 #include <QtGui/QMatrix4x4>
 #include <QtGui/QOffscreenSurface>
 
@@ -101,6 +102,10 @@ QT_BEGIN_NAMESPACE
   this way they do not have to redraw the entire window content on each
   paintGL() call.
 
+  Similarly to QOpenGLWidget, QOpenGLWindow supports the Qt::AA_ShareOpenGLContexts
+  attribute. When enabled, the OpenGL contexts of all QOpenGLWindow instances will share
+  with each other. This allows accessing each other's shareable OpenGL resources.
+
   For more information on graphics in Qt, see \l {Graphics}.
  */
 
@@ -196,6 +201,7 @@ public:
 
         if (!context) {
             context.reset(new QOpenGLContext);
+            context->setShareContext(qt_gl_global_share_context());
             context->setFormat(q->requestedFormat());
             if (!context->create())
                 qWarning("QOpenGLWindow::beginPaint: Failed to create context");