2 files changed, 15 insertions, 1 deletions
diff --git a/src/opengl/qwindowsurface_gl.cpp b/src/opengl/qwindowsurface_gl.cpp
index 7dc7dc7..b8716ce 100644
--- a/src/opengl/qwindowsurface_gl.cpp
+++ b/src/opengl/qwindowsurface_gl.cpp
@@ -284,6 +284,7 @@ struct QGLWindowSurfacePrivate
 };
 
 QGLFormat QGLWindowSurface::surfaceFormat;
+QGLWindowSurface::SwapMode QGLWindowSurface::swapBehavior = QGLWindowSurface::AutomaticSwap;
 
 void QGLWindowSurfaceGLPaintDevice::endPaint()
 {
@@ -541,6 +542,9 @@ void QGLWindowSurface::flush(QWidget *widget, const QRegion &rgn, const QPoint &
     const GLenum target = GL_TEXTURE_2D;
     Q_UNUSED(target);
 
+    if (QGLWindowSurface::swapBehavior == QGLWindowSurface::KillSwap)
+        return;
+
     if (context()) {
         context()->makeCurrent();
 
@@ -588,7 +592,14 @@ void QGLWindowSurface::flush(QWidget *widget, const QRegion &rgn, const QPoint &
                 }
             }
 #endif
-            bool doingPartialUpdate = hasPartialUpdateSupport() && br.width() * br.height() < parent->geometry().width() * parent->geometry().height() * 0.2;
+            bool doingPartialUpdate = false;
+            if (QGLWindowSurface::swapBehavior == QGLWindowSurface::AutomaticSwap)
+                doingPartialUpdate = hasPartialUpdateSupport() && br.width() * br.height() < parent->geometry().width() * parent->geometry().height() * 0.2;
+            else if (QGLWindowSurface::swapBehavior == QGLWindowSurface::AlwaysFullSwap)
+                doingPartialUpdate = false;
+            else if (QGLWindowSurface::swapBehavior == QGLWindowSurface::AlwaysPartialSwap)
+                doingPartialUpdate = hasPartialUpdateSupport();
+
             QGLContext *ctx = reinterpret_cast<QGLContext *>(parent->d_func()->extraData()->glContext);
             if (widget != window()) {
                 if (initializeOffscreenTexture(window()->size()))
diff --git a/src/opengl/qwindowsurface_gl_p.h b/src/opengl/qwindowsurface_gl_p.h
index 6906f35..9b0bee3 100644
--- a/src/opengl/qwindowsurface_gl_p.h
+++ b/src/opengl/qwindowsurface_gl_p.h
@@ -102,6 +102,9 @@ public:
 
     static QGLFormat surfaceFormat;
 
+    enum SwapMode { AutomaticSwap, AlwaysFullSwap, AlwaysPartialSwap, KillSwap };
+    static SwapMode swapBehavior;
+
 private slots:
     void deleted(QObject *object);