struct_ff_periodic_effect(9) defines parameters of a periodic force-feedback effect

SYNOPSIS


struct ff_periodic_effect {
__u16 waveform;
__u16 period;
__s16 magnitude;
__s16 offset;
__u16 phase;
struct ff_envelope envelope;
__u32 custom_len;
__s16 __user * custom_data;
};

MEMBERS

waveform

kind of the effect (wave)

period

period of the wave (ms)

magnitude

peak value

offset

mean value of the wave (roughly)

phase

'horizontal' shift

envelope

envelope data

custom_len

number of samples (FF_CUSTOM only)

custom_data

buffer of samples (FF_CUSTOM only)

DESCRIPTION

Known waveforms - FF_SQUARE, FF_TRIANGLE, FF_SINE, FF_SAW_UP, FF_SAW_DOWN, FF_CUSTOM. The exact syntax FF_CUSTOM is undefined for the time being as no driver supports it yet.

NOTE

the data pointed by custom_data is copied by the driver. You can therefore dispose of the memory after the upload/update.

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