[linux-audio-dev] +momentary, consolidated (ladspa.h.diff)

[Tim Goetze]

[Alfons Adriaensen]
>> It would send short trigger signals. I use ports like this in ams modules
>> that have a trigger output. And these ports are e.g. connected to a
>> "retrigger" port of an envelope or the "reset" port of a LFO.
>
>Why should a host care about knowing this ? It could only important if
>the trigger is connected to a GUI element that would be set into some
>state by the trigger and remain there until reset by the user.
>
>Unless we start 'typing' all ports, and expect to host to police all
>connections, TRIGGER / MOMENTARY is required only for display purposes.

we're already requiring hosts to police connections for value
conversions.

seeing that connecting a TRIGGER or MOMENTARY port to a 'continuous'
data source or destination implies unintended effects ranging to
perceived malfunction, i think it is only sensible to 'type' the
distinction.

>The two ends of a trigger connection are not symmetrical.

aren't they? can you expand on this, please?

>> "Hint LADSPA_HINT_MOMENTARY indicates that port is intended to be
>>  connected to a trigger signal emitting both rising and falling edge".
>
>I fail to see what this means. Either something sends out both rising and
>falling edges, OR it can send at most one edge during its entire lifetime.

i'll try to explain in terms of UI controls:

MOMENTARY: a push button, sending 'yes' when pressed and 'no' when
released.

TRIGGER: a push button, sending 'yes' only at press *or* release, and
'no' at any other point in time.

amicalement,

tim