/*==LICENSE==*

CyanWorlds.com Engine - MMOG client, server and tools
Copyright (C) 2011  Cyan Worlds, Inc.

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.

You can contact Cyan Worlds, Inc. by email legal@cyan.com
 or by snail mail at:
      Cyan Worlds, Inc.
      14617 N Newport Hwy
      Mead, WA   99021

*==LICENSE==*/
#ifndef PL_AVG_H
#define PL_AVG_H

#include "hsConfig.h"
#include "hsThread.h"
#include "hsStlUtils.h"


// A Time based Value Averaging class
//  implemented in a ring buffer
// Values are averaged over the RingLen
//  independant of frame time
// The ring buffer will grow to accomadate
//  as many samples as added during the Len
// Only Accurate to kPercision (0.001) of whatever units
//  of time are used

template <class T> class TimeBasedAvgRing
{
/* T must be a simple type

  If T is not a floating point type then rounding
  loss may occur when samples are interpolated
  at window boundries
*/
private:
    static const float kPercision;

    template <class S> class Item
    {
    private:
        T fValue;
        double fTime;
    public:
        Item() { Reset(); }
        Item(const T val, const double time) : fValue(val), fTime(time) { }
        void Reset() { fValue = 0; fTime = 0; }
        void SetValue(const T val) { fValue = val; }
        void SetTime(const double time) { fTime = time; }
        T GetValue() const { return fValue; }
        double GetTime() const { return fTime; }
    };
    typedef std::list< Item<T> > TimeList;
    typedef typename TimeList::iterator TimeListIterator; // .NET added typename to be C++ ISO compliant - JL

    TimeList fList;
    float fLen;  // in time
    float fAvg;
    float fMaxAvg;
    double fTotal;
    TimeListIterator fRingStart, fRingEnd;
    hsMutex fLock;
public:
    TimeBasedAvgRing():fLen(0.f),fAvg(0.f),fMaxAvg(0.f),fTotal(0.0) {}

    void SetRingLen(const float len) { fLen = len; }
    float GetRingLen() const { return fLen; }
    void AddItem(T value, double time);
    float GetAvg() const { return fAvg; }
    double GetTotal() const { return fTotal; }
    float GetMaxAvg() const { return fMaxAvg; }
    void ResetMaxAvg() { fMaxAvg=fAvg; }
    void Reset() { fRingStart=fRingEnd; ResetMaxAvg(); }
};


#endif  // PL_AVG_H