OSGTrackballNavigator.cpp

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/*---------------------------------------------------------------------------*\
 *                                OpenSG                                     *
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 *                                License                                    *
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 * This library is free software; you can redistribute it and/or modify it   *
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 * WITHOUT ANY WARRANTY; without even the implied warranty of                *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU         *
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\*---------------------------------------------------------------------------*/

#include <OSGConfig.h>
#include <OSGBaseTypes.h>
#include <OSGMatrix.h>
#include <OSGMatrixUtility.h>

#include "OSGNodePtr.h"
#include "OSGTrackballNavigator.h"

OSG_USING_NAMESPACE

/***************************************************************************\
 *                            Description                                  *
\***************************************************************************/

/*------------------------- constructors ----------------------------------*/

TrackballNavigator::TrackballNavigator(Real32 rSize): _rRadius(rSize)
{
    _finalMatrix.setIdentity();
    _tMatrix.setIdentity();
    _pFrom.setValues(0,0,0);
    _pAt  .setValues(0,0,1);
    _vUp  .setValues(0,1,0);
    _rDistance=(_pAt-_pFrom).length();
}

/*-------------------------- destructors ----------------------------------*/

TrackballNavigator::~TrackballNavigator()
{
}

/*------------------------------ get --------------------------------------*/

Matrix &TrackballNavigator::getMatrix()
{
    updateFinalMatrix();
    return _finalMatrix;
}

Pnt3f &TrackballNavigator::getFrom()
{
    _pFrom = (Pnt3f)_finalMatrix[3];
    return _pFrom;
}

Pnt3f &TrackballNavigator::getAt()
{
    _pAt = (Pnt3f)(_finalMatrix[3] - (_rDistance*_finalMatrix[2]));
    return _pAt;
}

Vec3f &TrackballNavigator::getUp()
{
    _vUp = (Vec3f)_finalMatrix[1];
    return _vUp;
}

Real32 TrackballNavigator::getDistance()
{
    return _rDistance;
}

/*------------------------------ set --------------------------------------*/


void TrackballNavigator::setFrom(Pnt3f new_from)
{
    set(new_from, getAt(), getUp());
}

void TrackballNavigator::setAt(Pnt3f new_at)
{
    set(getFrom(),new_at,getUp());
}

void TrackballNavigator::setDistance(Real32 new_distance)
{
    _rDistance = new_distance;
    updateFinalMatrix();
}

void TrackballNavigator::setUp(Vec3f new_up)
{
    set(getFrom(),getAt(),new_up);
}

void TrackballNavigator::set(Pnt3f new_from, Pnt3f new_at, Vec3f new_up)
{
    bool b = MatrixLookAt(_tMatrix, new_at, new_at+(new_at-new_from), new_up);
    if(!b)
    {
        _rDistance = (new_at - new_from).length();
        updateFinalMatrix();
    }
    else
    {
        FNOTICE(("TrackballNavigator: set(.,.,.), failed")); 
    }
}

void TrackballNavigator::set(Matrix new_matrix)
{
    // get distance
    Vec3f translation( new_matrix[3][0], new_matrix[3][1], new_matrix[3][2] );
    _rDistance = translation.length();

    _pFrom = (Pnt3f) new_matrix[3];
    _pAt   = (Pnt3f)(new_matrix[3] - (_rDistance * new_matrix[2]));
    _vUp   = (Vec3f) new_matrix[1];
    set(_pFrom, _pAt, _vUp);
}

/*-------------------- Trackball Transformations --------------------------*/

void TrackballNavigator::rotate(Real32 fromX, Real32 fromY, Real32 toX, Real32 toY)
{
    Quaternion qCurrVal;

    Vec3f  vAxis;
    Real32 rPhi;

    Vec3f  vP1, vP2, vDiff;

    Real32 rTmp;

    if(osgabs(fromX - toX) > Eps || osgabs(fromY - toY) > Eps)
    {
        vP1.setValues(fromX, fromY, projectToSphere(_rRadius, fromX, fromY));
        vP2.setValues(toX, toY, projectToSphere(_rRadius, toX, toY));

        vAxis = vP2;
        vAxis.crossThis(vP1);

        vDiff  = vP1;
        vDiff -= vP2;

        rTmp = osgClamp(-1.0f, vDiff.length() / (2.0f * _rRadius), 1.0f);

        rPhi = 2.0f * osgasin(rTmp);
        qCurrVal.setValueAsAxisRad(vAxis, rPhi);

        Matrix temp;
        qCurrVal.getValue(temp);

        _tMatrix.mult(temp);
    }
}

void TrackballNavigator::translateXY(Real32 distanceX, Real32 distanceY)
{
    Matrix temp;
    temp.setIdentity();
    temp.setTranslate(distanceX,distanceY,0);
    _tMatrix.mult(temp);
}

void TrackballNavigator::translateZ(Real32 distance)
{
    _rDistance+=distance;
    // don't navigate beyond the at point.
    //if(_rDistance < 0.0f)
    //    _rDistance = 0.0f;
}

Real32 TrackballNavigator::projectToSphere(Real32 rRadius, Real32 rX, Real32 rY)
{
    Real32 d, t, z;

    d = sqrt(rX * rX + rY * rY);

    if (d < rRadius * 0.70710678118654752440f)
    {    /* Inside sphere */
        z = sqrt(rRadius * rRadius - d * d);
    }
    else
    {    /* On hyperbola */
        t = rRadius / 1.41421356237309504880f;
        z = t * t / d;
    }

    return z;
}

void TrackballNavigator::updateFinalMatrix()
{
    Matrix temp;
    _finalMatrix=_tMatrix;
    temp.setIdentity();
    temp.setTranslate(0,0,_rDistance);

    _finalMatrix.mult(temp);
}


/*-------------------------------------------------------------------------*/
/*                              cvs id's                                   */

#ifdef __sgi
#pragma set woff 1174
#endif

#ifdef OSG_LINUX_ICC
#pragma warning( disable : 177 )
#endif

namespace
{
    static Char8 cvsid_cpp       [] = "@(#)$Id: OSGTrackballNavigator.cpp,v 1.5 2002/06/26 16:43:45 istoynov Exp $";
    static Char8 cvsid_hpp       [] = OSGTRACKBALLNAVIGATOR_HEADER_CVSID;
    //static Char8 cvsid_inl       [] = OSGNAVIGATOR_INLINE_CVSID;

    static Char8 cvsid_fields_hpp[] = OSGTRACKBALLNAVIGATOR_HEADER_CVSID;
}

---