1STRUCT FF_ENVELOPE(9) Input Subsystem STRUCT FF_ENVELOPE(9)
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6 struct_ff_envelope - generic force-feedback effect envelope
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9 struct ff_envelope {
10 __u16 attack_length;
11 __u16 attack_level;
12 __u16 fade_length;
13 __u16 fade_level;
14 };
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17 attack_length
18 duration of the attack (ms)
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20 attack_level
21 level at the beginning of the attack
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23 fade_length
24 duration of fade (ms)
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26 fade_level
27 level at the end of fade
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30 The attack_level and fade_level are absolute values; when applying
31 envelope force-feedback core will convert to positive/negative value
32 based on polarity of the default level of the effect. Valid range for
33 the attack and fade levels is 0x0000 - 0x7fff
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36Kernel Hackers Manual 2.6. November 2011 STRUCT FF_ENVELOPE(9)