/*---------------------------------------------------------------------------*
  Project:  NintendoWare
  File:     snd_MoveValue.h

  Copyright (C)2009-2010 Nintendo Co., Ltd./HAL Laboratory, Inc.  All rights reserved.

  These coded instructions, statements, and computer programs contain
  proprietary information of Nintendo of America Inc. and/or Nintendo
  Company Ltd., and are protected by Federal copyright law.  They may
  not be disclosed to third parties or copied or duplicated in any form,
  in whole or in part, without the prior written consent of Nintendo.

  $Revision: 13145 $
 *---------------------------------------------------------------------------*/

#ifndef NW_SND_MOVE_VALUE_H_
#define NW_SND_MOVE_VALUE_H_

namespace nw {
namespace snd {
namespace internal {

template< typename ValueType, typename CountType >
class MoveValue
{
  public:
    /*---------------------------------------------------------------------------*
      Name:         MoveValue

      Description:  コンストラクタ

      Arguments:    なし

      Returns:      なし
     *---------------------------------------------------------------------------*/
    MoveValue() : m_Origin(0), m_Target(0), m_Frame(0), m_Counter(0) {}

    /*---------------------------------------------------------------------------*
      Name:         InitValue

      Description:  値を初期化

      Arguments:    value : 初期化値

      Returns:      なし
     *---------------------------------------------------------------------------*/
    void InitValue( ValueType value )
    {
        m_Origin  = value;
        m_Target  = value;
        m_Frame   = 0;
        m_Counter = 0;
    }

    /*---------------------------------------------------------------------------*
      Name:         SetTarget

      Description:  変化させる値の目的値を設定する

      Arguments:    targetValue : 目的値
                    frames : 変化に要するフレーム数

      Returns:      なし
     *---------------------------------------------------------------------------*/
    void SetTarget( ValueType targetValue, CountType frames )
    {
        m_Origin  = GetValue();
        m_Target  = targetValue;
        m_Frame   = frames;
        m_Counter = 0;
    }

    /*---------------------------------------------------------------------------*
      Name:         GetTarget

      Description:  変化させる値の目的値を取得する

      Arguments:    targetValue : 目的値
                    frames : 変化に要するフレーム数

      Returns:      なし
     *---------------------------------------------------------------------------*/
    ValueType GetTarget() const { return m_Target; }

    /*---------------------------------------------------------------------------*
      Name:         GetValue

      Description:  現在の値を取得する

      Arguments:    なし

      Returns:      現在の値
     *---------------------------------------------------------------------------*/
    ValueType GetValue() const
    {
        if ( IsFinished() ) return m_Target;
        return static_cast<ValueType>(
            m_Origin + ( m_Target - m_Origin ) * m_Counter / m_Frame
        );
    }

    /*---------------------------------------------------------------------------*
      Name:         Update

      Description:  値を更新する

      Arguments:    なし

      Returns:      なし
     *---------------------------------------------------------------------------*/
    void Update() { if ( m_Counter < m_Frame ) ++m_Counter; }

    /*---------------------------------------------------------------------------*
      Name:         IsFinished

      Description:  カウンタが完了しているかどうかを返す

      Arguments:    なし

      Returns:      完了していたら true
     *---------------------------------------------------------------------------*/
    bool IsFinished() const { return m_Counter >= m_Frame; }

    /*---------------------------------------------------------------------------*
      Name:         GetRemainingCount

      Description:  ターゲット値に達するまでの残りのUpdate回数を取得する

      Arguments:    なし

      Returns:      残りのUpdate回数
     *---------------------------------------------------------------------------*/
    CountType GetRemainingCount() const
    {
        if ( IsFinished() ) return static_cast<CountType>( 0 );
        return m_Frame - m_Counter;
    }

  private:
    ValueType m_Origin;
    ValueType m_Target;
    CountType m_Frame;
    CountType m_Counter;
};

} // namespace nw::snd::internal
} // namespace nw::snd
} // namespace nw

#endif /* NW_SND_MOVE_VALUE_H_ */