Move scenegraph handling out of core

Replace Display{Producer,Consumer,FrameSink} with the new classes
Compositor and Compositor::Observer.

The Compositor subclasses are implemented by the OutputSurfaces,
replacing DisplayProducer in this role. Unlike DisplayProducer, the
new classes do not use QtQuick scenegraph types, but rather give
access to the software QImage or OpenGL texture directly.

The connection to the "other half" is simplified by replacing
DisplayConsumer with Compositor::Observer, which is no longer
implemented by RenderWidgetHostViewQt, but directly by its delegates
in the quick and widgets libraries. RenderWidgetHostViewQt now only
provides the delegate with a Compositor::Id which is used to connect
the corresponding Compositor and Observer.

The delegates are responsible for generating QtQuick scenegraph nodes
from the information provided by the Compositor subclasses.

Behavior with software and old OpenGL scenegraph backends is
unchanged: both continue to work. As for the RHI scenegraph backend,
the code here is correct but nonetheless not working: changes are
needed in qtbase to make RHI use the global share context for its
OpenGL context.

Fixes: QTBUG-78682
Change-Id: I837da8860a18ec366ed33f6ecc44c147245e1101
Reviewed-by: Michal Klocek <michal.klocek@qt.io>

1 files changed, 0 insertions, 69 deletions

diff --git a/src/core/compositor/display_producer.h b/src/core/compositor/display_producer.h
deleted file mode 100644
index 5de09d2d2..000000000
--- a/src/core/compositor/display_producer.h
+++ /dev/null
@@ -1,69 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2019 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the QtWebEngine module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#ifndef DISPLAY_PRODUCER_H
-#define DISPLAY_PRODUCER_H
-
-#include "qtwebenginecoreglobal_p.h"
-
-QT_BEGIN_NAMESPACE
-class QSGNode;
-QT_END_NAMESPACE
-
-namespace QtWebEngineCore {
-class RenderWidgetHostViewQtDelegate;
-
-// Produces composited frames for display.
-class DisplayProducer
-{
-public:
-    // Generate scene graph nodes for the current frame.
-    //
-    // If this is a scheduled update (that is, scheduleUpdate was called
-    // earlier), then updatePaintNode will generate nodes for a new frame.
-    // Otherwise, it will just regenerate nodes for the old frame.
-    virtual QSGNode *updatePaintNode(QSGNode *oldNode, RenderWidgetHostViewQtDelegate *delegate) = 0;
-
-protected:
-    ~DisplayProducer() {}
-};
-
-} // namespace QtWebEngineCore
-
-#endif // !DISPLAY_PRODUCER_H