Re: force feedback envelope incomplete

[Vojtech Pavlik <vojtech@suse.cz>]

On Sun, Oct 16, 2005 at 01:35:47PM -0500, Dmitry Torokhov wrote:
> On Saturday 15 October 2005 16:39, emard@softhome.net wrote:
> > HI
> > 
> > Force feedback envelope struct in input.h 
> > for periodic events is incomplete.
> > 
> > struct ff_envelope {
> >         __u16 attack_length;    /* Duration of attack (ms) */
> >         __u16 attack_level;     /* Level at beginning of attack */
> >         __u16 fade_length;      /* Duration of fade (ms) */
> >         __u16 fade_level;       /* Level at end of fade */
> > };
> > 
> > The envelope consists of:
> > 1. Attack level (Level at beginning of attack)
> > 2. Attack time
> > 3. Sustain level (Level at end of attack and beginning of fade)
> > 4. Sustain time
> > 5. Fade level (Level at the end of fade)
> > 6. Fade time
> > 
> > If I want to implement proper envelope I propose something like this:
> > 
> > struct ff_envelope {
> >         __u16 attack_length;    /* Duration of attack (ms) */
> >         __u16 attack_level;     /* Level at beginning of attack */
> >         __u16 sustain_length;   /* Duration of sustain (ms) */
> >         __u16 sustain_level;    /* Sustain Level at end of attack and beginning of fade */
> >         __u16 fade_length;      /* Duration of fade (ms) */
> >         __u16 fade_level;       /* Level at end of fade */
> > };
> 
> You might want to talk to Vojtech about this (CC-ed).
 
Your proposal seems reasonable. Please send me a patch that adds the
sustain members to the envelope, and uses it in some driver, while
making sure existing binary-only apps (if there are any) don't break.

-- 
Vojtech Pavlik
SuSE Labs, SuSE CR