1 // Copyright (c) 1999-2014 OPEN CASCADE SAS
2 //
3 // This file is part of Open CASCADE Technology software library.
4 //
5 // This library is free software; you can redistribute it and/or modify it under
6 // the terms of the GNU Lesser General Public License version 2.1 as published
7 // by the Free Software Foundation, with special exception defined in the file
8 // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
9 // distribution for complete text of the license and disclaimer of any warranty.
10 //
11 // Alternatively, this file may be used under the terms of Open CASCADE
12 // commercial license or contractual agreement.
13 
14 #ifndef _gp_QuaternionNLerp_HeaderFile
15 #define _gp_QuaternionNLerp_HeaderFile
16 
17 #include <gp_Quaternion.hxx>
18 
19 //! Class perform linear interpolation (approximate rotation interpolation),
20 //! result quaternion nonunit, its length lay between. sqrt(2)/2  and 1.0
21 class gp_QuaternionNLerp
22 {
23 public:
24 
25   //! Compute interpolated quaternion between two quaternions.
26   //! @param theStart first  quaternion
27   //! @param theEnd   second quaternion
28   //! @param theT normalized interpolation coefficient within 0..1 range,
29   //!             with 0 pointing to theStart and 1 to theEnd.
Interpolate(const gp_Quaternion & theQStart,const gp_Quaternion & theQEnd,Standard_Real theT)30   static gp_Quaternion Interpolate (const gp_Quaternion& theQStart,
31                                     const gp_Quaternion& theQEnd,
32                                     Standard_Real theT)
33   {
34     gp_Quaternion aResult;
35     gp_QuaternionNLerp aLerp (theQStart, theQEnd);
36     aLerp.Interpolate (theT, aResult);
37     return aResult;
38   }
39 
40 public:
41 
42   //! Empty constructor,
gp_QuaternionNLerp()43   gp_QuaternionNLerp() {}
44 
45   //! Constructor with initialization.
gp_QuaternionNLerp(const gp_Quaternion & theQStart,const gp_Quaternion & theQEnd)46   gp_QuaternionNLerp (const gp_Quaternion& theQStart, const gp_Quaternion& theQEnd)
47   {
48     Init (theQStart, theQEnd);
49   }
50 
51   //! Initialize the tool with Start and End values.
Init(const gp_Quaternion & theQStart,const gp_Quaternion & theQEnd)52   void Init (const gp_Quaternion& theQStart, const gp_Quaternion& theQEnd)
53   {
54     InitFromUnit (theQStart.Normalized(), theQEnd.Normalized());
55   }
56 
57   //! Initialize the tool with Start and End unit quaternions.
InitFromUnit(const gp_Quaternion & theQStart,const gp_Quaternion & theQEnd)58   void InitFromUnit (const gp_Quaternion& theQStart, const gp_Quaternion& theQEnd)
59   {
60     myQStart = theQStart;
61     myQEnd   = theQEnd;
62     Standard_Real anInner = myQStart.Dot (myQEnd);
63     if (anInner < 0.0)
64     {
65       myQEnd = -myQEnd;
66     }
67     myQEnd -= myQStart;
68   }
69 
70   //! Set interpolated quaternion for theT position (from 0.0 to 1.0)
Interpolate(Standard_Real theT,gp_Quaternion & theResultQ) const71   void Interpolate (Standard_Real theT, gp_Quaternion& theResultQ) const
72   {
73     theResultQ = myQStart + myQEnd * theT;
74   }
75 
76 private:
77 
78   gp_Quaternion myQStart;
79   gp_Quaternion myQEnd;
80 
81 };
82 
83 #endif //_gp_QuaternionNLerp_HeaderFile
84