<?xml version="1.0" encoding="ANSI_X3.4-1968" standalone="no"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<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_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="re706.html" title="struct ff_rumble_effect" /><link rel="next" href="re708.html" title="struct input_dev" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center"><span>struct ff_effect</span></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="re706.html">Prev</a> </td><th width="60%" align="center">Chapter 8. Input Subsystem</th><td width="20%" align="right"> <a accesskey="n" href="re708.html">Next</a></td></tr></table><hr /></div><div class="refentry" title="struct ff_effect"><a id="API-struct-ff-effect"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>struct ff_effect —
defines force feedback effect
</p></div><div class="refsynopsisdiv" title="Synopsis"><h2>Synopsis</h2><pre class="programlisting">
struct ff_effect {
__u16 type;
__s16 id;
__u16 direction;
struct ff_trigger trigger;
struct ff_replay replay;
union u;
}; </pre></div><div class="refsect1" title="Members"><a id="id3129471"></a><h2>Members</h2><div class="variablelist"><dl><dt><span class="term">type</span></dt><dd><p>
type of the effect (FF_CONSTANT, FF_PERIODIC, FF_RAMP, FF_SPRING,
FF_FRICTION, FF_DAMPER, FF_RUMBLE, FF_INERTIA, or FF_CUSTOM)
</p></dd><dt><span class="term">id</span></dt><dd><p>
an unique id assigned to an effect
</p></dd><dt><span class="term">direction</span></dt><dd><p>
direction of the effect
</p></dd><dt><span class="term">trigger</span></dt><dd><p>
trigger conditions (struct ff_trigger)
</p></dd><dt><span class="term">replay</span></dt><dd><p>
scheduling of the effect (struct ff_replay)
</p></dd><dt><span class="term">u</span></dt><dd><p>
effect-specific structure (one of ff_constant_effect, ff_ramp_effect,
ff_periodic_effect, ff_condition_effect, ff_rumble_effect) further
defining effect parameters
</p></dd></dl></div></div><div class="refsect1" title="Description"><a id="id3129555"></a><h2>Description</h2><p>
This structure is sent through ioctl from the application to the driver.
To create a new effect application should set its <em class="parameter"><code>id</code></em> to -1; the kernel
will return assigned <em class="parameter"><code>id</code></em> which can later be used to update or delete
this effect.
</p></div><div class="refsect1" title="Direction of the effect is encoded as follows"><a id="id3129580"></a><h2>Direction of the effect is encoded as follows</h2><p>
0 deg -> 0x0000 (down)
90 deg -> 0x4000 (left)
180 deg -> 0x8000 (up)
270 deg -> 0xC000 (right)
</p></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="re706.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="re708.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top"><span>struct ff_rumble_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 input_dev</span></td></tr></table></div></body></html>
