--- /dev/null
+// Copyright (c) 2021 OPEN CASCADE SAS
+//
+// This file is part of Open CASCADE Technology software library.
+//
+// This library is free software; you can redistribute it and/or modify it under
+// the terms of the GNU Lesser General Public License version 2.1 as published
+// by the Free Software Foundation, with special exception defined in the file
+// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
+// distribution for complete text of the license and disclaimer of any warranty.
+//
+// Alternatively, this file may be used under the terms of Open CASCADE
+// commercial license or contractual agreement.
+
+#ifndef _Graphic3d_TransformPersScaledAbove_HeaderFile
+#define _Graphic3d_TransformPersScaledAbove_HeaderFile
+
+#include <Graphic3d_TransformPers.hxx>
+
+DEFINE_STANDARD_HANDLE(Graphic3d_TransformPersScaledAbove, Graphic3d_TransformPers)
+
+//! Transformation Zoom persistence with the above boundary of scale.
+//! This persistence works only when the camera scale value is below the scale value of this persistence.
+//! Otherwise, no persistence is applied.
+class Graphic3d_TransformPersScaledAbove : public Graphic3d_TransformPers
+{
+public:
+ //! Create a Zoom transformation persistence with an anchor 3D point and a scale value
+ Standard_EXPORT Graphic3d_TransformPersScaledAbove (const Standard_Real theScale,
+ const gp_Pnt& thePnt);
+ //! Destructor
+ virtual ~Graphic3d_TransformPersScaledAbove() {}
+
+ //! Find scale value based on the camera position and view dimensions
+ //! If the camera scale value less than the persistence scale, zoom persistence is not applied.
+ //! @param theCamera [in] camera definition
+ //! @param theViewportWidth [in] the width of viewport.
+ //! @param theViewportHeight [in] the height of viewport.
+ Standard_EXPORT virtual Standard_Real persistentScale (const Handle(Graphic3d_Camera)& theCamera,
+ const Standard_Integer theViewportWidth,
+ const Standard_Integer theViewportHeight) const Standard_OVERRIDE;
+
+public:
+
+ DEFINE_STANDARD_RTTIEXT(Graphic3d_TransformPersScaledAbove, Graphic3d_TransformPers)
+
+private:
+ Standard_Real myScale; //!< scale bound value
+};
+
+#endif