/****************************************************************************

**

** Copyright (C) 2008-2010 Nokia Corporation and/or its subsidiary(-ies).

** All rights reserved.

** Contact: Nokia Corporation (developer.feedback@nokia.com)

**

** This file is part of the HbCore module of the UI Extensions for Mobile.

**

** GNU Lesser General Public License Usage

** This file may be used under the terms of the GNU Lesser General Public

** License version 2.1 as published by the Free Software Foundation and

** appearing in the file LICENSE.LGPL included in the packaging of this file.

** Please review the following information to ensure the GNU Lesser General

** Public License version 2.1 requirements will be met:

** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.

**

** In addition, as a special exception, Nokia gives you certain additional

** rights.  These rights are described in the Nokia Qt LGPL Exception

** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.

**

** If you have questions regarding the use of this file, please contact

** Nokia at developer.feedback@nokia.com.

**

****************************************************************************/

#include "hbvelocitycalculator_p.h"

#include "hbpointrecorder_p.h"

#include <QPointF>

#include <QTime>

#include <QDebug>

//#define VELOCITY_DEBUG

#ifndef VELOCITY_DEBUG

# define DEBUG if (0) qDebug

#else

# define DEBUG qDebug

#endif

/*!

   @hbcore

   \internals

   \class HbVelocityCalculator

   \brief Class to calculate velocity from point.

*/

/*!

    \internal

    \brief

    \return

*/

HbVelocityCalculator::HbVelocityCalculator(

    const HbPointRecorder& listX,

    const HbPointRecorder& listY )

    :

    mListX( listX ),

    mListY( listY )

{

}

/*!

    \internal

    \brief

    \return

*/

QPointF HbVelocityCalculator::velocity( const QTime& time ) const

{

    QPointF velocity(0.0, 0.0);

    velocity.setX(calculate_velocity(mListX, time));

    velocity.setY(calculate_velocity(mListY, time));

    DEBUG() << "Velocity: " << velocity;

    return velocity;

}

/*!

    \internal

    \brief

    \return

*/

qreal HbVelocityCalculator::calculate_velocity(

    const HbPointRecorder &list,

    const QTime& time ) const

{

    Q_UNUSED(time)

    if (list.count() < 2) {

        return 0.0;

    }

    DEBUG() << "Stationary time: " << list.lastTime().msecsTo(time);

        return 0.0;

    }

    // Accumulate the distance from previous point until we have sufficient sample

    qreal delta = 0.0;

    int timeDelta = 0;

    int i = list.count();

        i--;

        timeDelta = list.at(i).second.msecsTo(time);

    }

    delta = list.lastPoint() - list.at(i).first;

    return delta / (qreal)(list.at(i).second.msecsTo(time));

}