volume.h

游戏音频程序设计-Beginning.Game.Audio.Programming

// Volume.h: interface for the CVolume class.
//
//////////////////////////////////////////////////////////////////////

#if !defined(AFX_VOLUME_H__952DF093_63FD_4F81_AF58_77F3F250E633__INCLUDED_)
#define AFX_VOLUME_H__952DF093_63FD_4F81_AF58_77F3F250E633__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

namespace AudioEngine {

// represents a volume.  0 = silence, 1 = full volume.
class CVolume  
{
public:
  CVolume() { m_Neg96ToZero = 0.0f; }
  CVolume(double neg96_to_zero) { Set(neg96_to_zero); }

  virtual ~CVolume() { }

  void Set(double neg96_to_zero) {
    if (neg96_to_zero < -96.0) neg96_to_zero = -96.0;
    if (neg96_to_zero > 0.0) neg96_to_zero = 0.0;
    m_Neg96ToZero = neg96_to_zero;
  }
  CVolume &operator=(double value) { Set(value); return(*this); }

  double Get() const { return(m_Neg96ToZero); }
  void Maximize() { Set(0); }
  void Minimize() { Set(-96.0); }

  long ToDirectMusic() const { return((long)(m_Neg96ToZero * 100.0)); }
  void FromDirectMusic(long dmvol) { Set(dmvol / 100); }

  operator double() const { return(m_Neg96ToZero); }

protected:
  double m_Neg96ToZero;
};

}; // namespace

#endif // !defined(AFX_VOLUME_H__952DF093_63FD_4F81_AF58_77F3F250E633__INCLUDED_)