5 files changed, 37 insertions, 23 deletions
diff --git a/src/opengl/qgraphicssystem_gl.cpp b/src/opengl/qgraphicssystem_gl.cpp
index a282e4c..58cc28a 100644
--- a/src/opengl/qgraphicssystem_gl.cpp
+++ b/src/opengl/qgraphicssystem_gl.cpp
@@ -40,6 +40,7 @@
 ****************************************************************************/
 
 #include "qgraphicssystem_gl_p.h"
+#include <QGraphicsView>
 
 #include "private/qpixmap_raster_p.h"
 #include "private/qpixmapdata_gl_p.h"
@@ -47,7 +48,7 @@
 #include "private/qgl_p.h"
 #include <private/qwindowsurface_raster_p.h>
 
-#if defined(Q_WS_X11) && defined(QT_OPENGL_ES)
+#if defined(Q_WS_X11) && !defined(QT_NO_EGL)
 #include "private/qpixmapdata_x11gl_p.h"
 #include "private/qwindowsurface_x11gl_p.h"
 #endif
@@ -58,10 +59,6 @@ extern QGLWidget *qt_gl_getShareWidget();
 
 QPixmapData *QGLGraphicsSystem::createPixmapData(QPixmapData::PixelType type) const
 {
-#if defined(Q_WS_X11) && defined(QT_OPENGL_ES)
-    if (type == QPixmapData::PixmapType && QX11GLPixmapData::hasX11GLPixmaps())
-        return new QX11GLPixmapData();
-#endif
     return new QGLPixmapData(type);
 }
 
@@ -75,9 +72,18 @@ QWindowSurface *QGLGraphicsSystem::createWindowSurface(QWidget *widget) const
         return new QRasterWindowSurface(widget);
 #endif
 
-#if defined(Q_WS_X11) && defined(QT_OPENGL_ES)
-    if (QX11GLPixmapData::hasX11GLPixmaps())
-        return new QX11GLWindowSurface(widget);
+#if defined(Q_WS_X11) && !defined(QT_NO_EGL)
+    if (m_useX11GL && QX11GLPixmapData::hasX11GLPixmaps()) {
+        // If the widget is a QGraphicsView which will be re-drawing the entire
+        // scene each frame anyway, we should use QGLWindowSurface as this may
+        // provide proper buffer flipping, which should be faster than QX11GL's
+        // blitting approach:
+        QGraphicsView* qgv = qobject_cast<QGraphicsView*>(widget);
+        if (qgv && qgv->viewportUpdateMode() == QGraphicsView::FullViewportUpdate)
+            return new QGLWindowSurface(widget);
+        else
+            return new QX11GLWindowSurface(widget);
+    }
 #endif
 
     return new QGLWindowSurface(widget);
diff --git a/src/opengl/qgraphicssystem_gl_p.h b/src/opengl/qgraphicssystem_gl_p.h
index ff47854..9d2d506 100644
--- a/src/opengl/qgraphicssystem_gl_p.h
+++ b/src/opengl/qgraphicssystem_gl_p.h
@@ -62,10 +62,12 @@ QT_BEGIN_NAMESPACE
 class Q_OPENGL_EXPORT QGLGraphicsSystem : public QGraphicsSystem
 {
 public:
-    QGLGraphicsSystem();
+    QGLGraphicsSystem(bool useX11GL);
 
     QPixmapData *createPixmapData(QPixmapData::PixelType type) const;
     QWindowSurface *createWindowSurface(QWidget *widget) const;
+private:
+    bool m_useX11GL;
 };
 
 QT_END_NAMESPACE
diff --git a/src/opengl/qpixmapdata_x11gl_egl.cpp b/src/opengl/qpixmapdata_x11gl_egl.cpp
index 58d34fc..e0c274a 100644
--- a/src/opengl/qpixmapdata_x11gl_egl.cpp
+++ b/src/opengl/qpixmapdata_x11gl_egl.cpp
@@ -216,18 +216,16 @@ QX11GLSharedContexts* QX11GLPixmapData::sharedContexts()
 
 bool QX11GLPixmapData::hasX11GLPixmaps()
 {
-    static bool checkedForX11Pixmaps = false;
-    static bool haveX11Pixmaps = false;
+    static bool checkedForX11GLPixmaps = false;
+    static bool haveX11GLPixmaps = false;
 
-    if (checkedForX11Pixmaps)
-        return haveX11Pixmaps;
+    if (checkedForX11GLPixmaps)
+        return haveX11GLPixmaps;
 
-    checkedForX11Pixmaps = true;
+    checkedForX11GLPixmaps = true;
+    haveX11GLPixmaps = sharedContexts()->isValid();
 
-    if (!qgetenv("QT_USE_X11GL_PIXMAPS").isEmpty() && sharedContexts()->isValid())
-        haveX11Pixmaps = true;
-
-    return haveX11Pixmaps;
+    return haveX11GLPixmaps;
 }
 
 QX11GLPixmapData::QX11GLPixmapData()
diff --git a/src/opengl/qwindowsurface_gl.cpp b/src/opengl/qwindowsurface_gl.cpp
index bcb96fa..92a347b 100644
--- a/src/opengl/qwindowsurface_gl.cpp
+++ b/src/opengl/qwindowsurface_gl.cpp
@@ -94,8 +94,8 @@ QT_BEGIN_NAMESPACE
 #ifdef Q_WS_WIN
 extern Q_GUI_EXPORT bool qt_win_owndc_required;
 #endif
-QGLGraphicsSystem::QGLGraphicsSystem()
-    : QGraphicsSystem()
+QGLGraphicsSystem::QGLGraphicsSystem(bool useX11GL)
+    : QGraphicsSystem(), m_useX11GL(useX11GL)
 {
     QGLWindowSurface::surfaceFormat.setSampleBuffers(true);
 #if defined(Q_WS_X11) && !defined(QT_OPENGL_ES)
diff --git a/src/plugins/graphicssystems/opengl/main.cpp b/src/plugins/graphicssystems/opengl/main.cpp
index abcfb7f..4c740ca 100644
--- a/src/plugins/graphicssystems/opengl/main.cpp
+++ b/src/plugins/graphicssystems/opengl/main.cpp
@@ -59,6 +59,9 @@ QStringList QGLGraphicsSystemPlugin::keys() const
 #if !defined(QT_OPENGL_ES_1)
     list << QLatin1String("OpenGL2");
 #endif
+#if defined(Q_WS_X11) && !defined(QT_NO_EGL)
+    list << QLatin1String("X11GL");
+#endif
     return list;
 }
 
@@ -66,18 +69,23 @@ QGraphicsSystem* QGLGraphicsSystemPlugin::create(const QString& system)
 {
     if (system.toLower() == QLatin1String("opengl1")) {
         QGL::setPreferredPaintEngine(QPaintEngine::OpenGL);
-        return new QGLGraphicsSystem;
+        return new QGLGraphicsSystem(false);
     }
 
 #if !defined(QT_OPENGL_ES_1)
     if (system.toLower() == QLatin1String("opengl2")) {
         QGL::setPreferredPaintEngine(QPaintEngine::OpenGL2);
-        return new QGLGraphicsSystem;
+        return new QGLGraphicsSystem(false);
     }
 #endif
 
+#if defined(Q_WS_X11) && !defined(QT_NO_EGL)
+    if (system.toLower() == QLatin1String("x11gl"))
+        return new QGLGraphicsSystem(true);
+#endif
+
     if (system.toLower() == QLatin1String("opengl"))
-        return new QGLGraphicsSystem;
+        return new QGLGraphicsSystem(false);
 
     return 0;
 }