利用Directsound 3D实现游戏中3D音效

//初始化Dsound HRESULT hr; if(FAILED(hr = DirectSoundCreate8(NULL,&g_pDsd,NULL))) 　return FALSE; if(FAILED(hr = g_pDsd->SetCooperativeLevel(m_hWnd,DSSCL_PRIORITY))) 　return FALSE; //初始化Directsound 的主缓冲区，并设置格式 LPDIRECTSOUNDBUFFER pDSBPrimary = NULL; DSBUFFERDESC dsbdesc ; ZeroMemory(&dsbdesc,sizeof(DSBUFFERDESC)); dsbdesc.dwSize = sizeof(DSBUFFERDESC); dsbdesc.dwFlags = DSBCAPS_CTRL3D | DSBCAPS_PRIMARYBUFFER;//一定不要忘记创建主缓冲区的时候要设置DSBCAPS_CTRL3D标志。只有指定了这个标志，后面你才能从这个辅助缓冲区中请求到3D的buffer指针。 if(FAILED(hr = g_pDsd->CreateSoundBuffer(&dsbdesc,&pDSBPrimary ,NULL))) 　return FALSE; 　//获取3D 模拟世界中的听者指针。 if( FAILED( hr = pDSBPrimary->QueryInterface( IID_IDirectSound3DListener, (VOID**)&g_pDSListener ) ) ) 　return FALSE; WAVEFORMATEX wfx; ZeroMemory( &wfx, sizeof(WAVEFORMATEX) ); wfx.wFormatTag = (WORD) WAVE_FORMAT_PCM; wfx.nChannels = WAVECHANNEL ; wfx.nSamplesPerSec = WAVESAMPLEPERSEC ; wfx.wBitsPerSample = WAVEBITSPERSAMPLE ; wfx.nBlockAlign = (WORD) (wfx.wBitsPerSample / 8 * wfx.nChannels); wfx.nAvgBytesPerSec = (DWORD) (wfx.nSamplesPerSec * wfx.nBlockAlign); if( FAILED( hr = pDSBPrimary->SetFormat(&wfx) ) ) //设置缓冲区的音频格式。 　return FALSE;

　　第3步，创建辅助缓冲区，通过辅助缓冲区获取3dbuffer指针

DSBUFFERDESC dsbd; ZeroMemory( &dsbd, sizeof(DSBUFFERDESC) ); dsbd.dwSize = sizeof(DSBUFFERDESC); dsbd.dwFlags = DSBCAPS_CTRL3D| DSBCAPS_GLOBALFOCUS | DSBCAPS_CTRLPOSITIONNOTIFY |DSBCAPS_GETCURRENTPOSITION2; //看看创建辅助缓冲区的buffer时设置的标志，3D的标志自然是需要的，还有一个标志需要注意，DSBCAPS_CTRLPOSITIONNOTIFY，如果你采用的流（stream）buffer的话，就需要边播放，边向buffer中填充数据，就需要设置这个标志，这样，在directsound播放到指定位置时，就会触发事件。 //dsbd.dwBufferBytes =MAX_AUDIO_BUF * BUFFERNOTIFYSIZE ;//如果采用流buffer，可以设置适当的buffer大小。 dsbd.dwBufferBytes =g_pWaveFile->GetSize(); // 如果采用静态buffer，那么buffer的大小就是文件的大小了。 dsbd.guid3DAlgorithm = guid3DAlgorithm; dsbd.lpwfxFormat = g_pWaveFile->m_pwfx; if(FAILED(hr = g_pDsd->CreateSoundBuffer(&dsbd,&g_pDSBuffer,NULL))) 　return ; 　//通过辅助缓冲区，来获取3D buffer的指针。 if(FAILED(hr = g_pDSBuffer->QueryInterface(IID_IDirectSound3DBuffer, (VOID**)&g_pDS3DBuffer ))) 　return ; g_dsBufferParams.dwSize = sizeof(DS3DBUFFER); g_pDS3DBuffer->GetAllParameters( &g_dsBufferParams ); //设置3Dbuffer的属性。 g_dsBufferParams.dwMode = DS3DMODE_HEADRELATIVE; g_pDS3DBuffer->SetAllParameters( &g_dsBufferParams, DS3D_IMMEDIATE );

　　第4步 设置多普勒因子以及最小最大距离。

FLOAT fDopplerFactor; FLOAT fRolloffFactor; FLOAT fMinDistance; FLOAT fMaxDistance; CSliderCtrl *pDopplerSlider = (CSliderCtrl*)GetDlgItem(IDC_DOPPLER_SLIDER); fDopplerFactor = pDopplerSlider->GetPos(); CSliderCtrl *pRolloffSlider= (CSliderCtrl*)GetDlgItem(IDC_ROLLOFF_SLIDER); fRolloffFactor = pRolloffSlider->GetPos(); CSliderCtrl *pMinDistSlider = (CSliderCtrl*)GetDlgItem(IDC_MINDISTANCE_SLIDER ); fMinDistance = pMinDistSlider->GetPos(); CSliderCtrl *pMaxDistSlider = (CSliderCtrl*)GetDlgItem(IDC_MAXDISTANCE_SLIDER ); fMaxDistance = pMaxDistSlider->GetPos(); g_dsListenerParams.flDopplerFactor = fDopplerFactor; g_dsListenerParams.flRolloffFactor = fRolloffFactor; if( g_pDSListener ) { 　g_pDSListener->SetAllParameters( &g_dsListenerParams, DS3D_DEFERRED ); 　g_pDSListener->CommitDeferredSettings(); } g_dsBufferParams.flMinDistance = fMinDistance; g_dsBufferParams.flMaxDistance = fMaxDistance; if( g_pDS3DBuffer ) 　g_pDS3DBuffer->SetAllParameters( &g_dsBufferParams, DS3D_DEFERRED );

　　第5步 然后就是通过调用辅助缓冲区的play方法，来进行播放音频文件了。