DRV_SetPenSamplingDist

Adjusts the granularity of the pen packets sent by the pen driver. DRV_SetPenSamplingDist instructs the pen driver to filter out packets that have not moved a specified number of tablet units (called the sampling distance) from the last reported location.

• If successful, returns the previous sampling distance; otherwise, the Windows SendDriverMessage function returns DRV_FAILURE.

lParam1

The low-order word contains the number of tablet units the pen should move before a new point is generated.

lParam2

Should be set to zero.

The default value for the sampling distance is zero. In other words, all points are reported. Note that the sampling rate is based on a sampling distance of zero. If the sampling distance is set to a value other then zero, pen packets will be filtered out of the data stream. Thus, the rate at which the system receives pen packets may be less than the specified sampling rate because the pen driver sends only packets that reflect minimum movement.