| Microsoft DirectX 9.0 |
The SetRolloffFactor method sets the rolloff factor, which determines the rate of attenuation over distance.
Syntax
HRESULT SetRolloffFactor(
D3DVALUE flRolloffFactor,
DWORD dwApply
);
Parameters
flRolloffFactor
Rolloff factor. D3DVALUE is defined as float.
dwApply
Value that specifies when the setting should be applied. This value must be one of the following:
| Value | Description |
| DS3D_DEFERRED | Settings are not applied until the application calls the IDirectSound3DListener8::CommitDeferredSettings method. This allows the application to change several settings and generate a single recalculation. |
| DS3D_IMMEDIATE | Settings are applied immediately, causing the system to recalculate the 3-D coordinates for all 3-D sound buffers. |
Return Values
If the method succeeds, the return value is DS_OK.
If the method fails, the return value may be DSERR_INVALIDPARAM.
Remarks
The rolloff factor has a range of DS3D_MINROLLOFFFACTOR (no rolloff) to DS3D_MAXROLLOFFFACTOR (defined as 10 times the rolloff found in the real world). The default value is DS3D_DEFAULTROLLOFFFACTOR (1.0). For more information, see Rolloff Factor.
Requirements
Header: Declared in dsound.h.
See Also