Subject: Re: +trigger, Re: [linux-audio-dev] ladspa.h.diff
From: Tim Goetze (tim_AT_quitte.de)
Date: Sat Mar 06 2004 - 15:24:38 EET
[Steve Harris]
>On Sat, Mar 06, 2004 at 02:52:43 +0100, Tim Goetze wrote:
>> >You just use a regular control port to specify
>> >your threshold/amplitude. The trigger port just does the "triggering".
>>
>> the proposed patch fits this model well: a plugin need only specify
>> TOGGLED in addition to TRIGGER.
>>
>> at the same time, connecting a 'velocity'-enhanced trigger source to a
>> port defining TRIGGER without TOGGLED is possible with the minimum
>> need of transmission logic (conditionals, ports) in the host as well
>> as in the plugin.
>
>So what does the TRIGGER hint mean? For a normal gate CV signal (which I
>think is what youre talking about) there is no need for a hint.
a gate CV signal is already covered by TOGGLED: states are binary 0 or
1, transition is possible at any time. no need to use another hint
bit.
>I dont see how you can have a momentary control which is anything other
>than boolean, you press it, the signal goes high, you release it, it goes
>low. I dont see hoe you can fit a variable amplitude in there, something
>like a slider or knob has no momentary action.
the second paragraph above is intended to cover MIDI input from a
keyboard, drumpad or the likes. as you will recall, the trigger
signals emitted from such sources are one-shot and not binary.
-
it seems we haven't even covered what you describe here: connecting
both rising and falling edge of a control signal to a port. your
intention seems to use 'TRIGGER | TOGGLED' for this purpose. but i
doubt this is really useful: it forces the signal edge detection on
the plugin, which requires another memory location and control logic
to do that. while this procedure may be true to analog circuitry, in
the digital domain this is not practical because we do not deal with
continuous signals, but rather with events already expressing the
derivative: rising edge, falling edge.
-
i conclude that your understanding of TRIGGER is better described by
MOMENTARY, which, incidentally, is the word you used first iirc. if i
understand correctly, your intention is to connect an ordinary button
(of the return-to-zero-on-release kind) to a port indicating TOGGLED
| MOMENTARY. does that do your idea justice?
amicalement,
tim
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