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<html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968" /><title>struct ff_periodic_effect</title><meta name="generator" content="DocBook XSL Stylesheets V1.75.2" /><link rel="home" href="index.html" title="Linux Device Drivers" /><link rel="up" href="ch08.html" title="Chapter 8. Input Subsystem" /><link rel="prev" href="re699.html" title="struct ff_condition_effect" /><link rel="next" href="re701.html" title="struct ff_rumble_effect" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center"><span>struct ff_periodic_effect</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="re699.html">Prev</a> </td><th width="60%" align="center">Chapter 8. Input Subsystem</th><td width="20%" align="right"> <a accesskey="n" href="re701.html">Next</a></td></tr></table><hr /></div><div class="refentry" title="struct ff_periodic_effect"><a id="API-struct-ff-periodic-effect"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>struct ff_periodic_effect —
defines parameters of a periodic force-feedback effect
</p></div><div class="refsynopsisdiv" title="Synopsis"><h2>Synopsis</h2><pre class="programlisting">
struct ff_periodic_effect {
__u16 waveform;
__u16 period;
__s16 magnitude;
__s16 offset;
__u16 phase;
struct ff_envelope envelope;
__u32 custom_len;
__s16 * custom_data;
}; </pre></div><div class="refsect1" title="Members"><a id="id2697754"></a><h2>Members</h2><div class="variablelist"><dl><dt><span class="term">waveform</span></dt><dd><p>
kind of the effect (wave)
</p></dd><dt><span class="term">period</span></dt><dd><p>
period of the wave (ms)
</p></dd><dt><span class="term">magnitude</span></dt><dd><p>
peak value
</p></dd><dt><span class="term">offset</span></dt><dd><p>
mean value of the wave (roughly)
</p></dd><dt><span class="term">phase</span></dt><dd><p>
'horizontal' shift
</p></dd><dt><span class="term">envelope</span></dt><dd><p>
envelope data
</p></dd><dt><span class="term">custom_len</span></dt><dd><p>
number of samples (FF_CUSTOM only)
</p></dd><dt><span class="term">custom_data</span></dt><dd><p>
buffer of samples (FF_CUSTOM only)
</p></dd></dl></div></div><div class="refsect1" title="Description"><a id="id2697856"></a><h2>Description</h2><p>
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.
</p></div><div class="refsect1" title="Note"><a id="id2697869"></a><h2>Note</h2><p>
the data pointed by custom_data is copied by the driver.
You can therefore dispose of the memory after the upload/update.
</p></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="re699.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="ch08.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="re701.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span>struct ff_condition_effect</span> </td><td width="20%" align="center"><a accesskey="h" href="index.html">Home</a></td><td width="40%" align="right" valign="top"> <span>struct ff_rumble_effect</span></td></tr></table></div></body></html>
