Enable QX11GLWindowSurface using "-graphicssystem x11gl" option

When the OpenGL graphics system is in X11GL mode, it will use the
QX11GLWindowSurface for all widgets except QGraphicsViews with the
FullViewportUpdate update mode set, where it will use the regular
QGLWindowSurface, as this is probabbly faster.

QX11GLWindowSurface differs from QGLWindowSurface because it allows
accelerated scrolling and partial updates, while still being using
opengl to do rendering.

Task-number: QT-280
Task-number: QT-2625
Reviewed-By: Trond

1 files changed, 14 insertions, 8 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);