Microsoft DirectX 9.0 SDK Update (Summer 2004)

^{Step 1: Create the Audiopath}

The simplest way to create an audiopath is by passing a flag to IDirectMusicPerformance8::InitAudio. The tutorial sample passes the DMUS_APATH_DYNAMIC_STEREO flag, causing InitAudio to set up a default audiopath that supports stereo sounds:

g_pPerformance->InitAudio( 
    NULL,        // IDirectMusic interface not needed.
    NULL,        // IDirectSound interface not needed.
    NULL,        // Window handle.
    DMUS_APATH_DYNAMIC_STEREO, // Default audiopath type.
    64,          // Number of performance channels.
    DMUS_AUDIOF_ALL,     // Features on synthesizer.
    NULL         // Audio parameters; use defaults.
);

The default audiopath is suitable for sounds that do not have to be located in space, such as background music or narration. However, if an application implements 3-D sound effects, it will play each sound source on its own audiopath, so that 3-D parameters can be set individually.

The sample creates one such audiopath as follows:

IDirectMusicAudioPath8* p3DAudioPath = NULL;
g_pPerformance->CreateStandardAudioPath( 
    DMUS_APATH_DYNAMIC_3D,  // Path type.
    64,                     // Number of performance channels.
    TRUE,                   // Activate now.
    &p3DAudioPath           // Pointer that receives audiopath.
);

A segment can now be played on this audiopath as follows:

g_pPerformance->PlaySegmentEx(
    g_pSegment,  // Segment to play.
    NULL,        // Not used.
    NULL,        // For transitions. 
    0,           // Flags.
    0,           // Start time; 0 is immediate.
    NULL,        // Pointer that receives segment state.
    NULL,        // Object to stop.
    p3DAudioPath // Audiopath.
);  

Next: Step 2: Retrieve the Buffer

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© 2004 Microsoft Corporation. All rights reserved.