Fixed bug when using QGLWidgets in -graphicssystem opengl

We need to make sure that the FBO is bound in a valid context.

Reviewed-by: Tom

2 files changed, 18 insertions, 1 deletions

diff --git a/src/opengl/qglframebufferobject.cpp b/src/opengl/qglframebufferobject.cpp
index 5585208..9674cfb 100644
--- a/src/opengl/qglframebufferobject.cpp
+++ b/src/opengl/qglframebufferobject.cpp
@@ -331,8 +331,22 @@ void QGLFBOGLPaintDevice::setFBO(QGLFramebufferObject* f,
     }
 }
 
+QGLContext *QGLFBOGLPaintDevice::context() const
+{
+    QGLContext *fboContext = const_cast<QGLContext *>(fbo->d_ptr->fbo_guard.context());
+    QGLContext *currentContext = const_cast<QGLContext *>(QGLContext::currentContext());
+
+    if (QGLContextPrivate::contextGroup(fboContext) == QGLContextPrivate::contextGroup(currentContext))
+        return currentContext;
+    else
+        return fboContext;
+}
+
 void QGLFBOGLPaintDevice::ensureActiveTarget()
 {
+    if (QGLContext::currentContext() != context())
+        context()->makeCurrent();
+
     QGLContext* ctx = const_cast<QGLContext*>(QGLContext::currentContext());
     Q_ASSERT(ctx);
     const GLuint fboId = fbo->d_func()->fbo();
@@ -344,6 +358,9 @@ void QGLFBOGLPaintDevice::ensureActiveTarget()
 
 void QGLFBOGLPaintDevice::beginPaint()
 {
+    if (QGLContext::currentContext() != context())
+        context()->makeCurrent();
+
     // We let QFBO track the previously bound FBO rather than doing it
     // ourselves here. This has the advantage that begin/release & bind/end
     // work as expected.
diff --git a/src/opengl/qglframebufferobject_p.h b/src/opengl/qglframebufferobject_p.h
index 055a752..43d4a41 100644
--- a/src/opengl/qglframebufferobject_p.h
+++ b/src/opengl/qglframebufferobject_p.h
@@ -109,7 +109,7 @@ class QGLFBOGLPaintDevice : public QGLPaintDevice
 public:
     virtual QPaintEngine* paintEngine() const {return fbo->paintEngine();}
     virtual QSize size() const {return fbo->size();}
-    virtual QGLContext* context() const {return const_cast<QGLContext *>(QGLContext::currentContext());}
+    virtual QGLContext* context() const;
     virtual QGLFormat format() const {return fboFormat;}
     virtual void ensureActiveTarget();
     virtual void beginPaint();