New texture sharing protocol and infrastructure

This adds a higher level protocol on top of the server buffer extension,
providing an easy way for Qt Quick applications to use the shared
textures.

[ChangeLog] Added protocol and Qt Quick image provider for sharing
textures in graphics memory between compositor and multiple clients.

Task-number: QTBUG-73822
Change-Id: Idc41b3479d6ca37be35d9ccd7b89e9994ff17f8f
Reviewed-by: Johan Helsing <johan.helsing@qt.io>
(cherry picked from commit 80001cbf0451f4ba2a971fb20b80dc8e25ac604d)
Reviewed-by: Paul Olav Tvete <paul.tvete@qt.io>

1 files changed, 97 insertions, 0 deletions

diff --git a/src/imports/texture-sharing/plugin.cpp b/src/imports/texture-sharing/plugin.cpp
new file mode 100644
index 000000000..9cf6bbca1
--- /dev/null
+++ b/src/imports/texture-sharing/plugin.cpp
@@ -0,0 +1,97 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtWaylandClient 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.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtQml/qqmlextensionplugin.h>
+#include <QtQml/qqmlengine.h>
+
+#include "sharedtextureprovider.h"
+
+/*!
+    \qmlmodule QtWayland.Client.TextureSharing 1
+    \title Qt Wayland Shared Texture Provider
+    \ingroup qmlmodules
+    \brief Adds an image provider which utilizes shared GPU memory
+
+    \section2 Summary
+
+    This module allows Qt Wayland clients to use graphical resources exported
+    by the compositor, without allocating any graphics memory in the client.
+    \section2 Usage
+
+    To use this module, import it like this:
+    \code
+    import QtWayland.Client.TextureSharing 1.0
+    \endcode
+
+    The sharing functionality is provided through a QQuickImageProvider. Use
+    the "image:" scheme for the URL source of the image, followed by the
+    identifier \e wlshared, followed by the image file path. For example:
+
+    \code
+    Image { source: "image://wlshared/wallpapers/mybackground.jpg" }
+    \endcode
+
+    The shared texture module does not provide any directly usable QML types.
+*/
+
+QT_BEGIN_NAMESPACE
+
+class QWaylandTextureSharingPlugin : public QQmlExtensionPlugin
+{
+    Q_OBJECT
+    Q_PLUGIN_METADATA(IID QQmlExtensionInterface_iid)
+public:
+    QWaylandTextureSharingPlugin(QObject *parent = nullptr) : QQmlExtensionPlugin(parent) {}
+
+    void registerTypes(const char *uri) override
+    {
+        Q_ASSERT(uri == QStringLiteral("QtWayland.Client.TextureSharing"));
+        qmlRegisterModule(uri, 1, 0);
+    }
+
+    void initializeEngine(QQmlEngine *engine, const char *uri) override
+    {
+        Q_UNUSED(uri);
+        engine->addImageProvider("wlshared", new SharedTextureProvider);
+    }
+};
+
+QT_END_NAMESPACE
+
+#include "plugin.moc"