Begins playing an effect. If the effect is already playing, it is restarted from the beginning. If the effect has not been downloaded or has been modified since its last download, it is downloaded before being started. This default behavior can be suppressed by passing the FFES_NODOWNLOAD flag.


func FFEffectStart(_ effectReference: FFEffectObjectReference!, _ iterations: UInt32, _ flags: FFEffectStartFlag) -> HRESULT



An opaque reference handle to an effect object. This is obtained from a previous call to FFDeviceCreateEffect.


Number of times to play the effect in sequence. The envelope is re-articulated with each iteration.

To play the effect exactly once, pass 1. To play the effect repeatedly until explicitly stopped, pass INFINITE. To play the effect until explicitly stopped without re-articulating the envelope, modify the effect parameters with the FFEffect_SetParameters method, and change the dwDuration member to INFINITE.


Flags that describe how the effect should be played by the device. The value can be 0 or one or more of the following values:


All other effects on the device should be stopped before the specified effect is played. If this flag is omitted, the effect is mixed with existing effects already started on the device.


Do not automatically download the effect.

Return Value

If the method succeeds, the return value is FF_OK. If the method fails, the return value can be one of the following error values:









Not all devices support multiple iterations.

See Also


func FFCreateDevice(io_service_t, UnsafeMutablePointer<FFDeviceObjectReference?>!) -> HRESULT

Creates a new API device object from an OS object in preparation to use the device for force feedback.

func FFDeviceReleaseEffect(FFDeviceObjectReference!, FFEffectObjectReference!) -> HRESULT

Disposes of an API effect object created with FFDeviceCreateEffect.

func FFEffectDownload(FFEffectObjectReference!) -> HRESULT

Places the effect on the device. If the effect is already on the device, the existing effect is updated to match the values set by the FFEffectSetParameters method.

func FFEffectUnload(FFEffectObjectReference!) -> HRESULT

Removes the effect from the device. If the effect is playing, it is automatically stopped before it is unloaded.

func FFIsForceFeedback(io_service_t) -> HRESULT

Used to determine if a particular device provided by HID Manager is a force feedback device.

func FFReleaseDevice(FFDeviceObjectReference!) -> HRESULT

Disposes of an API device object created with FFCreateDevice.