Move resetOpenGLState() to QQuickFbo

QQuickWindow should not have OpenGL specifics in its API in Qt 6.

However, resetOpenGLState() is used by applications commonly in
combination with QQuickFramebufferObject (not the least because the
documentation recommends it!). This is no problem in practice because
QQuickFramebufferObject remains an OpenGL-only feature. So to minimize
the breaks, move the function into QQuickFramebufferObject::Renderer so
any application that calls the function can continue to do so by just
calling it on 'this' instead.

The rendercontrol_opengl example used to call this function as well, but
unnecessarily, it will still function the same way without it.

Note that there is a chance that there are applications that call
resetOpenGLState() in other contexts, for example in slots connected to
before or afterRendering(). For these it will need to be determined if
the call is necessary at all, and if it is, should be replaced by
(re)setting the appropriate OpenGL state manually instead.

Task-number: QTBUG-84523
Change-Id: I335599f77e8a84e347a44427eb1a1bf917796ee8
Reviewed-by: Christian Strømme <christian.stromme@qt.io>

1 files changed, 0 insertions, 2 deletions

diff --git a/examples/quick/rendercontrol/rendercontrol_opengl/window_singlethreaded.cpp b/examples/quick/rendercontrol/rendercontrol_opengl/window_singlethreaded.cpp
index 9435c004a7..0d29a155dd 100644
--- a/examples/quick/rendercontrol/rendercontrol_opengl/window_singlethreaded.cpp
+++ b/examples/quick/rendercontrol/rendercontrol_opengl/window_singlethreaded.cpp
@@ -206,9 +206,7 @@ void WindowSingleThreaded::render()
     m_renderControl->render();
     m_renderControl->endFrame();
 
-    m_quickWindow->resetOpenGLState();
     QOpenGLFramebufferObject::bindDefault();
-
     m_context->functions()->glFlush();
 
     m_quickReady = true;