OgreDualQuaternion.cpp

/*
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This source file is part of OGRE
    (Object-oriented Graphics Rendering Engine)
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*/

/* dqconv.c

  Conversion routines between (regular quaternion, translation) and dual quaternion.

  Version 1.0.0, February 7th, 2007

  Copyright (C) 2006-2007 University of Dublin, Trinity College, All Rights 
  Reserved

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the author(s) be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.

  Author: Ladislav Kavan, kavanl@cs.tcd.ie

*/

#include "OgreStableHeaders.h"
#include "OgreDualQuaternion.h"


namespace Ogre {

    //Based on dqconv.c from http://isg.cs.tcd.ie/projects/DualQuaternions/
    //-----------------------------------------------------------------------
    void DualQuaternion::fromRotationTranslation (const Quaternion& q, const Vector3& trans)
    {
        // non-dual part (just copy the quaternion):
        w = q.w;
        x = q.x;
        y = q.y;
        z = q.z;
        
        // dual part:
        Real half = 0.5;
        dw = -half *  (trans.x * x + trans.y * y + trans.z * z ); 
        dx =  half *  (trans.x * w + trans.y * z - trans.z * y ); 
        dy =  half * (-trans.x * z + trans.y * w + trans.z * x ); 
        dz =  half *  (trans.x * y - trans.y * x + trans.z * w ); 
    }

    //Based on dqconv.c from http://isg.cs.tcd.ie/projects/DualQuaternions/
    //-----------------------------------------------------------------------
    void DualQuaternion::toRotationTranslation (Quaternion& q, Vector3& translation) const
    {
        // regular quaternion (just copy the non-dual part):
        q.w = w;
        q.x = x;
        q.y = y;
        q.z = z;

        // translation vector:
        Real doub = 2.0;
        translation.x = doub * (-dw*x + dx*w - dy*z + dz*y);
        translation.y = doub * (-dw*y + dx*z + dy*w - dz*x);
        translation.z = doub * (-dw*z - dx*y + dy*x + dz*w);
    }

    //-----------------------------------------------------------------------
    void DualQuaternion::fromTransformationMatrix (const Affine3& kTrans)
    {
        Vector3 pos;
        Vector3 scale;
        Quaternion rot;

        kTrans.decomposition(pos, scale, rot);
        fromRotationTranslation(rot, pos);
    }

    //-----------------------------------------------------------------------
    void DualQuaternion::toTransformationMatrix (Affine3& kTrans) const
    {
        Vector3 pos;
        Quaternion rot;
        toRotationTranslation(rot, pos);

        Vector3 scale = Vector3::UNIT_SCALE;
        kTrans.makeTransform(pos, scale, rot);
    }
}