Allow customizing the default fbo from the QPlatformGLContext.

Reviewed-by: Jørgen Lind

4 files changed, 20 insertions, 0 deletions

diff --git a/src/gui/kernel/qplatformglcontext_qpa.cpp b/src/gui/kernel/qplatformglcontext_qpa.cpp
index 36db2b0..4fcd9b8 100644
--- a/src/gui/kernel/qplatformglcontext_qpa.cpp
+++ b/src/gui/kernel/qplatformglcontext_qpa.cpp
@@ -44,6 +44,18 @@
 QPlatformGLContext::~QPlatformGLContext()
 { }
 
+/*!
+    The frame buffer object that a QGLWidget is painted to and that gets bound
+    when a QGLFramebufferObject is released.
+
+    The default implementation returns 0, which denotes the default
+    window-system provided frame buffer.
+*/
+GLuint QPlatformGLContext::defaultFBO() const
+{
+    return 0;
+}
+
 static QPlatformGLContext *staticSharedContext = 0;
 
 void QPlatformGLContext::setDefaultSharedContext(QPlatformGLContext *sharedContext)
diff --git a/src/gui/kernel/qplatformglcontext_qpa.h b/src/gui/kernel/qplatformglcontext_qpa.h
index d235848..9bfe676 100644
--- a/src/gui/kernel/qplatformglcontext_qpa.h
+++ b/src/gui/kernel/qplatformglcontext_qpa.h
@@ -57,6 +57,7 @@ public:
     virtual void doneCurrent() = 0;
     virtual void swapBuffers() = 0;
     virtual void* getProcAddress(const QString& procName) = 0;
+    virtual GLuint defaultFBO() const;
 
     virtual QPlatformWindowFormat platformWindowFormat() const = 0;
 
diff --git a/src/opengl/qgl_qpa.cpp b/src/opengl/qgl_qpa.cpp
index 5f0bca3..b05df64 100644
--- a/src/opengl/qgl_qpa.cpp
+++ b/src/opengl/qgl_qpa.cpp
@@ -139,6 +139,7 @@ bool QGLContext::chooseContext(const QGLContext* shareContext)
         }
         d->platformContext = widget->platformWindow()->glContext();
         Q_ASSERT(d->platformContext);
+        d->default_fbo = d->platformContext->defaultFBO();
         d->glFormat = qt_platformwindowformat_to_glformat(d->platformContext->platformWindowFormat());
         d->valid =(bool) d->platformContext;
     }
diff --git a/src/opengl/qglpaintdevice.cpp b/src/opengl/qglpaintdevice.cpp
index e1dcbfd..e12fdae 100644
--- a/src/opengl/qglpaintdevice.cpp
+++ b/src/opengl/qglpaintdevice.cpp
@@ -166,6 +166,12 @@ void QGLWidgetGLPaintDevice::setWidget(QGLWidget* w)
 
 void QGLWidgetGLPaintDevice::beginPaint()
 {
+    // ### This should be in setWidget(), but the context of the QGLWidget
+    // hasn't been set there yet.
+#ifdef Q_WS_QPA
+    m_thisFBO = context()->d_ptr->platformContext->defaultFBO();
+#endif
+
     QGLPaintDevice::beginPaint();
     if (!glWidget->d_func()->disable_clear_on_painter_begin && glWidget->autoFillBackground()) {
         if (glWidget->testAttribute(Qt::WA_TranslucentBackground))