dsutil.cpp

游戏编程精华02－含有几十个游戏编程例子

    pWaveFile = new CWaveFile();
    pWaveFile->Open( strWaveFileName, NULL, WAVEFILE_READ );

    // Figure out how big the DSound buffer should be 
    dwDSBufferSize = dwNotifySize * dwNotifyCount;

    // Set up the direct sound buffer.  Request the NOTIFY flag, so
    // that we are notified as the sound buffer plays.  Note, that using this flag
    // may limit the amount of hardware acceleration that can occur. 
    DSBUFFERDESC dsbd;
    ZeroMemory( &dsbd, sizeof(DSBUFFERDESC) );
    dsbd.dwSize          = sizeof(DSBUFFERDESC);
    dsbd.dwFlags         = dwCreationFlags | 
                           DSBCAPS_CTRLPOSITIONNOTIFY | 
                           DSBCAPS_GETCURRENTPOSITION2;
    dsbd.dwBufferBytes   = dwDSBufferSize;
    dsbd.guid3DAlgorithm = guid3DAlgorithm;
    dsbd.lpwfxFormat     = pWaveFile->m_pwfx;

    if( FAILED( hr = m_pDS->CreateSoundBuffer( &dsbd, &pDSBuffer, NULL ) ) )
    {
        // If wave format isn't then it will return 
        // either DSERR_BADFORMAT or E_INVALIDARG
        if( hr == DSERR_BADFORMAT || hr == E_INVALIDARG )
            return DXTRACE_ERR_NOMSGBOX( TEXT("CreateSoundBuffer"), hr );

        return DXTRACE_ERR( TEXT("CreateSoundBuffer"), hr );
    }

    // Create the notification events, so that we know when to fill
    // the buffer as the sound plays. 
    if( FAILED( hr = pDSBuffer->QueryInterface( IID_IDirectSoundNotify, 
                                                (VOID**)&pDSNotify ) ) )
    {
        SAFE_DELETE( aPosNotify );
        return DXTRACE_ERR( TEXT("QueryInterface"), hr );
    }

    aPosNotify = new DSBPOSITIONNOTIFY[ dwNotifyCount ];
    if( aPosNotify == NULL )
        return E_OUTOFMEMORY;

    for( DWORD i = 0; i < dwNotifyCount; i++ )
    {
        aPosNotify[i].dwOffset     = (dwNotifySize * i) + dwNotifySize - 1;
        aPosNotify[i].hEventNotify = hNotifyEvent;             
    }
    
    // Tell DirectSound when to notify us. The notification will come in the from 
    // of signaled events that are handled in WinMain()
    if( FAILED( hr = pDSNotify->SetNotificationPositions( dwNotifyCount, 
                                                          aPosNotify ) ) )
    {
        SAFE_RELEASE( pDSNotify );
        SAFE_DELETE( aPosNotify );
        return DXTRACE_ERR( TEXT("SetNotificationPositions"), hr );
    }

    SAFE_RELEASE( pDSNotify );
    SAFE_DELETE( aPosNotify );

    // Create the sound
    *ppStreamingSound = new CStreamingSound( pDSBuffer, dwDSBufferSize, pWaveFile, dwNotifySize );

    return S_OK;
}




//-----------------------------------------------------------------------------
// Name: CSound::CSound()
// Desc: Constructs the class
//-----------------------------------------------------------------------------
CSound::CSound( LPDIRECTSOUNDBUFFER* apDSBuffer, DWORD dwDSBufferSize, 
                DWORD dwNumBuffers, CWaveFile* pWaveFile )
{
    DWORD i;

    m_apDSBuffer = new LPDIRECTSOUNDBUFFER[dwNumBuffers];
    for( i=0; i<dwNumBuffers; i++ )
        m_apDSBuffer[i] = apDSBuffer[i];

    m_dwDSBufferSize = dwDSBufferSize;
    m_dwNumBuffers   = dwNumBuffers;
    m_pWaveFile      = pWaveFile;

    FillBufferWithSound( m_apDSBuffer[0], FALSE );

    // Make DirectSound do pre-processing on sound effects
    for( i=0; i<dwNumBuffers; i++ )
        m_apDSBuffer[i]->SetCurrentPosition(0);
}




//-----------------------------------------------------------------------------
// Name: CSound::~CSound()
// Desc: Destroys the class
//-----------------------------------------------------------------------------
CSound::~CSound()
{
    for( DWORD i=0; i<m_dwNumBuffers; i++ )
    {
        SAFE_RELEASE( m_apDSBuffer[i] ); 
    }

    SAFE_DELETE_ARRAY( m_apDSBuffer ); 
    SAFE_DELETE( m_pWaveFile );
}




//-----------------------------------------------------------------------------
// Name: CSound::FillBufferWithSound()
// Desc: Fills a DirectSound buffer with a sound file 
//-----------------------------------------------------------------------------
HRESULT CSound::FillBufferWithSound( LPDIRECTSOUNDBUFFER pDSB, BOOL bRepeatWavIfBufferLarger )
{
    HRESULT hr; 
    VOID*   pDSLockedBuffer      = NULL; // Pointer to locked buffer memory
    DWORD   dwDSLockedBufferSize = 0;    // Size of the locked DirectSound buffer
    DWORD   dwWavDataRead        = 0;    // Amount of data read from the wav file 

    if( pDSB == NULL )
        return CO_E_NOTINITIALIZED;

    // Make sure we have focus, and we didn't just switch in from
    // an app which had a DirectSound device
    if( FAILED( hr = RestoreBuffer( pDSB, NULL ) ) ) 
        return DXTRACE_ERR( TEXT("RestoreBuffer"), hr );

    // Lock the buffer down
    if( FAILED( hr = pDSB->Lock( 0, m_dwDSBufferSize, 
                                 &pDSLockedBuffer, &dwDSLockedBufferSize, 
                                 NULL, NULL, 0L ) ) )
        return DXTRACE_ERR( TEXT("Lock"), hr );

    // Reset the wave file to the beginning 
    m_pWaveFile->ResetFile();

    if( FAILED( hr = m_pWaveFile->Read( (BYTE*) pDSLockedBuffer,
                                        dwDSLockedBufferSize, 
                                        &dwWavDataRead ) ) )           
        return DXTRACE_ERR( TEXT("Read"), hr );

    if( dwWavDataRead == 0 )
    {
        // Wav is blank, so just fill with silence
        FillMemory( (BYTE*) pDSLockedBuffer, 
                    dwDSLockedBufferSize, 
                    (BYTE)(m_pWaveFile->m_pwfx->wBitsPerSample == 8 ? 128 : 0 ) );
    }
    else if( dwWavDataRead < dwDSLockedBufferSize )
    {
        // If the wav file was smaller than the DirectSound buffer, 
        // we need to fill the remainder of the buffer with data 
        if( bRepeatWavIfBufferLarger )
        {       
            // Reset the file and fill the buffer with wav data
            DWORD dwReadSoFar = dwWavDataRead;    // From previous call above.
            while( dwReadSoFar < dwDSLockedBufferSize )
            {  
                // This will keep reading in until the buffer is full 
                // for very short files
                if( FAILED( hr = m_pWaveFile->ResetFile() ) )
                    return DXTRACE_ERR( TEXT("ResetFile"), hr );

                hr = m_pWaveFile->Read( (BYTE*)pDSLockedBuffer + dwReadSoFar,
                                        dwDSLockedBufferSize - dwReadSoFar,
                                        &dwWavDataRead );
                if( FAILED(hr) )
                    return DXTRACE_ERR( TEXT("Read"), hr );

                dwReadSoFar += dwWavDataRead;
            } 
        }
        else
        {
            // Don't repeat the wav file, just fill in silence 
            FillMemory( (BYTE*) pDSLockedBuffer + dwWavDataRead, 
                        dwDSLockedBufferSize - dwWavDataRead, 
                        (BYTE)(m_pWaveFile->m_pwfx->wBitsPerSample == 8 ? 128 : 0 ) );
        }
    }

    // Unlock the buffer, we don't need it anymore.
    pDSB->Unlock( pDSLockedBuffer, dwDSLockedBufferSize, NULL, 0 );

    return S_OK;
}




//-----------------------------------------------------------------------------
// Name: CSound::RestoreBuffer()
// Desc: Restores the lost buffer. *pbWasRestored returns TRUE if the buffer was 
//       restored.  It can also NULL if the information is not needed.
//-----------------------------------------------------------------------------
HRESULT CSound::RestoreBuffer( LPDIRECTSOUNDBUFFER pDSB, BOOL* pbWasRestored )
{
    HRESULT hr;

    if( pDSB == NULL )
        return CO_E_NOTINITIALIZED;
    if( pbWasRestored )
        *pbWasRestored = FALSE;

    DWORD dwStatus;
    if( FAILED( hr = pDSB->GetStatus( &dwStatus ) ) )
        return DXTRACE_ERR( TEXT("GetStatus"), hr );

    if( dwStatus & DSBSTATUS_BUFFERLOST )
    {
        // Since the app could have just been activated, then
        // DirectSound may not be giving us control yet, so 
        // the restoring the buffer may fail.  
        // If it does, sleep until DirectSound gives us control.
        do 
        {
            hr = pDSB->Restore();
            if( hr == DSERR_BUFFERLOST )
                Sleep( 10 );
        }
        while( hr = pDSB->Restore() );

        if( pbWasRestored != NULL )
            *pbWasRestored = TRUE;

        return S_OK;
    }
    else
    {
        return S_FALSE;
    }
}




//-----------------------------------------------------------------------------
// Name: CSound::GetFreeBuffer()
// Desc: Checks to see if a buffer is playing and returns TRUE if it is.
//-----------------------------------------------------------------------------
LPDIRECTSOUNDBUFFER CSound::GetFreeBuffer()
{
    BOOL bIsPlaying = FALSE;

    if( m_apDSBuffer == NULL )
        return FALSE; 

    for( DWORD i=0; i<m_dwNumBuffers; i++ )
    {
        if( m_apDSBuffer[i] )
        {  
            DWORD dwStatus = 0;
            m_apDSBuffer[i]->GetStatus( &dwStatus );
            if ( ( dwStatus & DSBSTATUS_PLAYING ) == 0 )
                break;
        }
    }

    if( i != m_dwNumBuffers )
        return m_apDSBuffer[ i ];
    else
        return m_apDSBuffer[ rand() % m_dwNumBuffers ];
}




//-----------------------------------------------------------------------------
// Name: CSound::GetBuffer()
// Desc: 
//-----------------------------------------------------------------------------
LPDIRECTSOUNDBUFFER CSound::GetBuffer( DWORD dwIndex )
{
    if( m_apDSBuffer == NULL )
        return NULL;
    if( dwIndex >= m_dwNumBuffers )
        return NULL;

    return m_apDSBuffer[dwIndex];
}




//-----------------------------------------------------------------------------
// Name: CSound::Get3DBufferInterface()
// Desc: 
//-----------------------------------------------------------------------------
HRESULT CSound::Get3DBufferInterface( DWORD dwIndex, LPDIRECTSOUND3DBUFFER* ppDS3DBuffer )
{
    if( m_apDSBuffer == NULL )
        return CO_E_NOTINITIALIZED;
    if( dwIndex >= m_dwNumBuffers )
        return E_INVALIDARG;

    *ppDS3DBuffer = NULL;

    return m_apDSBuffer[dwIndex]->QueryInterface( IID_IDirectSound3DBuffer, 
                                                  (VOID**)ppDS3DBuffer );
}


//-----------------------------------------------------------------------------
// Name: CSound::Play()
// Desc: Plays the sound using voice management flags.  Pass in DSBPLAY_LOOPING
//       in the dwFlags to loop the sound
//-----------------------------------------------------------------------------
HRESULT CSound::Play( DWORD dwPriority, DWORD dwFlags )
{
    HRESULT hr;
    BOOL    bRestored;

    if( m_apDSBuffer == NULL )
        return CO_E_NOTINITIALIZED;

    LPDIRECTSOUNDBUFFER pDSB = GetFreeBuffer();

    if( pDSB == NULL )
        return DXTRACE_ERR( TEXT("GetFreeBuffer"), E_FAIL );

    // Restore the buffer if it was lost
    if( FAILED( hr = RestoreBuffer( pDSB, &bRestored ) ) )
        return DXTRACE_ERR( TEXT("RestoreBuffer"), hr );

    if( bRestored )
    {
        // The buffer was restored, so we need to fill it with new data
        if( FAILED( hr = FillBufferWithSound( pDSB, FALSE ) ) )
            return DXTRACE_ERR( TEXT("FillBufferWithSound"), hr );

        // Make DirectSound do pre-processing on sound effects
        Reset();
    }

    return pDSB->Play( 0, dwPriority, dwFlags );
}




//-----------------------------------------------------------------------------
// Name: CSound::Stop()
// Desc: Stops the sound from playing
//-----------------------------------------------------------------------------
HRESULT CSound::Stop()
{
    if( m_apDSBuffer == NULL )
        return CO_E_NOTINITIALIZED;

    HRESULT hr = 0;

    for( DWORD i=0; i<m_dwNumBuffers; i++ )
        hr |= m_apDSBuffer[i]->Stop();

    return hr;
}




//-----------------------------------------------------------------------------
// Name: CSound::Reset()
// Desc: Reset all of the sound buffers
//-----------------------------------------------------------------------------
HRESULT CSound::Reset()
{
    if( m_apDSBuffer == NULL )
        return CO_E_NOTINITIALIZED;

    HRESULT hr = 0;

    for( DWORD i=0; i<m_dwNumBuffers; i++ )
        hr |= m_apDSBuffer[i]->SetCurrentPosition( 0 );

    return hr;
}