struct ff_envelope(9)
NAME
struct_ff_envelope - generic force-feedback effect envelope
SYNOPSIS
struct ff_envelope {
__u16 attack_length;
__u16 attack_level;
__u16 fade_length;
__u16 fade_level;
};
MEMBERS
- attack_length
- duration of the attack (ms)
- attack_level
- level at the beginning of the attack
- fade_length
- duration of fade (ms)
- fade_level
- level at the end of fade
DESCRIPTION
The attack_level and fade_level are absolute values; when applying
envelope force-feedback core will convert to positive/negative value
based on polarity of the default level of the effect. Valid range for
the attack and fade levels is 0x0000 - 0x7fff