include/opencascade/NCollection_Lerp.hxx

0001 // Created by: Kirill GAVRILOV
0002 // Copyright (c) 2016 OPEN CASCADE SAS
0003 //
0004 // This file is part of Open CASCADE Technology software library.
0005 //
0006 // This library is free software; you can redistribute it and/or modify it under
0007 // the terms of the GNU Lesser General Public License version 2.1 as published
0008 // by the Free Software Foundation, with special exception defined in the file
0009 // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
0010 // distribution for complete text of the license and disclaimer of any warranty.
0011 //
0012 // Alternatively, this file may be used under the terms of Open CASCADE
0013 // commercial license or contractual agreement.
0014
0015 #ifndef _NCollection_Lerp_HeaderFile
0016 #define _NCollection_Lerp_HeaderFile
0017
0018 //! Simple linear interpolation tool (also known as mix() in GLSL).
0019 //! The main purpose of this template class is making interpolation routines more readable.
0020 template<class T>
0021 class NCollection_Lerp
0022 {
0023 public:
0024   //! Compute interpolated value between two values.
0025   //! @param theStart first  value
0026   //! @param theEnd   second value
0027   //! @param theT normalized interpolation coefficient within [0, 1] range,
0028   //!             with 0 pointing to theStart and 1 to theEnd.
0029   static T Interpolate (const T& theStart,
0030                         const T& theEnd,
0031                         double theT)
0032   {
0033     T aResult;
0034     NCollection_Lerp aLerp (theStart, theEnd);
0035     aLerp.Interpolate (theT, aResult);
0036     return aResult;
0037   }
0038
0039 public:
0040
0041   //! Empty constructor
0042   NCollection_Lerp() : myStart(), myEnd() {}
0043
0044   //! Main constructor.
0045   NCollection_Lerp (const T& theStart, const T& theEnd)
0046   {
0047     Init (theStart, theEnd);
0048   }
0049
0050   //! Initialize values.
0051   void Init (const T& theStart, const T& theEnd)
0052   {
0053     myStart = theStart;
0054     myEnd   = theEnd;
0055   }
0056
0057   //! Compute interpolated value between two values.
0058   //! @param theT normalized interpolation coefficient within [0, 1] range,
0059   //!             with 0 pointing to first value and 1 to the second value.
0060   //! @param theResult [out] interpolated value
0061   void Interpolate (double theT, T& theResult) const
0062   {
0063     theResult = (1.0 - theT) * myStart + theT * myEnd;
0064   }
0065
0066 private:
0067   T myStart;
0068   T myEnd;
0069 };
0070
0071 #endif // _NCollection_Lerp_HeaderFile