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diff --git a/include/svx/e3dsceneupdater.hxx b/include/svx/e3dsceneupdater.hxx
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+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   Licensed to the Apache Software Foundation (ASF) under one or more
+ *   contributor license agreements. See the NOTICE file distributed
+ *   with this work for additional information regarding copyright
+ *   ownership. The ASF licenses this file to you under the Apache
+ *   License, Version 2.0 (the "License"); you may not use this file
+ *   except in compliance with the License. You may obtain a copy of
+ *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#ifndef INCLUDED_SVX_E3DSCENEUPDATER_HXX
+#define INCLUDED_SVX_E3DSCENEUPDATER_HXX
+
+#include <svx/svxdllapi.h>
+#include <drawinglayer/geometry/viewinformation3d.hxx>
+#include <optional>
+
+class SdrObject;
+class E3dScene;
+
+/** Helper for 3d object changes affecting 2d geometry
+
+   This class is a helper to encapsulate 3D object changes which shall
+   change the scene's 2D geometry. E.g. when moving one 3D object in a
+   scene, the visualisation would not change since the scene's 2D
+   attributes are defined by its 2D object transformation and the
+   changed content would be projected to the same 2D bounds as
+   before. To reflect the fact that the 2D positions may 'change' for
+   the user's imagination, it is necessary to calculate a new 2D
+   object transformation of the scene (the SnapRect) using the old 3D
+   transformation stack and the possibly modified 3D content and to
+   use it. This is only desirable if changes to the scene's content
+   are intended to change the scene's 2D geometry attributes
+*/
+class SVXCORE_DLLPUBLIC E3DModifySceneSnapRectUpdater
+{
+    // the scene which may be changed. This gets set to the outmost scene
+    // of the to-be-changed 3D object when the scene has a 3d transformation
+    // stack at construction time. In all other cases it's set to zero and
+    // no action needs to be taken
+    E3dScene* mpScene;
+
+    // the 3d transformation stack at the time of construction, valid when
+    // mpScene is not zero
+    std::optional<drawinglayer::geometry::ViewInformation3D> mpViewInformation3D;
+
+public:
+    // the constructor evaluates and sets the members at construction time
+    E3DModifySceneSnapRectUpdater(const SdrObject* mpObject);
+
+    // the destructor will take action if mpScene is not zero and modify the
+    // 2D geometry of the target scene
+    ~E3DModifySceneSnapRectUpdater();
+};
+
+#endif // INCLUDED_SVX_E3DSCENEUPDATER_HXX
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */