DSoundHelpers.h

#ifndef DSOUND_HELPERS
#define DSOUND_HELPERS 1
 
#ifdef _WIN32
#include <windows.h>
#include <wtypes.h>
#endif
 
struct IDirectSound;
struct IDirectSoundBuffer;
 
class DSound
{
  public:
    IDirectSound* GetDS() const { return m_pDS; }
    bool IsEmulated() const;
 
    DSound();
    ~DSound();
    std::string Init();
 
  private:
    IDirectSound* m_pDS;
    static BOOL CALLBACK EnumCallback(LPGUID lpGuid,
                                      LPCSTR lpcstrDescription,
                                      LPCSTR lpcstrModule,
                                      LPVOID lpContext);
 
    void SetPrimaryBufferMode();
};
 
class DSoundBuf
{
  public:
    enum hw
    {
        HW_HARDWARE,
        HW_SOFTWARE,
        HW_DONT_CARE
    };
 
    /* If samplerate is DYNAMIC_SAMPLERATE, then call SetSampleRate before
     * you use the sample. */
    enum
    {
        DYNAMIC_SAMPLERATE = -1
    };
 
    DSoundBuf();
    std::string Init(DSound& ds,
                     hw hardware,
                     int iChannels,
                     int iSampleRate,
                     int iSampleBits,
                     int iWriteAhead);
 
    bool get_output_buf(char** pBuffer, unsigned* iBuffersize, int iChunksize);
    void release_output_buf(char* pBuffer, unsigned iBuffersize);
 
    void Play();
    void Stop();
    void SetVolume(float fVolume);
    void SetSampleRate(int iRate);
    int GetSampleRate() const { return m_iSampleRate; }
 
    ~DSoundBuf();
    int64_t GetPosition() const;
    int64_t GetOutputPosition() const { return m_iWriteCursorPos; }
 
  private:
    int buffersize_frames() const { return m_iBufferSize / bytes_per_frame(); }
    int bytes_per_frame() const { return m_iChannels * m_iSampleBits / 8; }
 
    void CheckWriteahead(int iCursorStart, int iCursorEnd);
    void CheckUnderrun(int iCursorStart, int iCursorEnd);
 
    IDirectSoundBuffer* m_pBuffer;
 
    int m_iChannels, m_iSampleRate, m_iSampleBits, m_iWriteAhead;
    int m_iVolume;
 
    int m_iBufferSize;
 
    int m_iWriteCursor, m_iBufferBytesFilled; /* bytes */
    int m_iExtraWriteahead;
    int64_t m_iWriteCursorPos; /* frames */
    mutable int64_t m_iLastPosition;
    bool m_bPlaying;
 
    bool m_bBufferLocked;
    char *m_pLockedBuf1, *m_pLockedBuf2;
    int m_iLockedSize1, m_iLockedSize2;
    char* m_pTempBuffer;
 
    int m_iLastCursors[4][2];
};
 
#endif