[gmpi] Draft reqs - Parameters - Modulation?
- From: "Angus F. Hewlett" <angus@xxxxxxxxxxxxx>
- To: gmpi@xxxxxxxxxxxxx
- Date: Sat, 11 Dec 2004 17:37:53 +0000
Hi,
Apologies if this has already been discussed to death - have been off
the list for a while. A brief search of the archives didn't turn
anything up.
I note in the requirements:-*
Req 52: * Every parameter is either stateful or non-stateful. This
parameter property may not change over the lifetime of a plugin.
Now, in an API I designed for something we're doing in-house, we found
it very useful for parameters to have both a static and dynamic state,
to support realtime modulation in a flexible way without messing with
the settings the user wants to persist for the plug.
There's a clear difference, for example, between setting the cutoff of a
filter by twisting a knob, and changing it by modulating it with an LFO.
When state-save happens for the plug, you want the former to be
persisted, and the latter not.
So, my question is, does the group propose that:-
A) plug-ins that wish to support this kind of thing expose multiple
parameters for the same fundamental thing (say Filter Cutoff, stateful,
and Filter Cutoff MOD, non-stateful)?
B) in general, the host is the arbiter of all modulations, so a host
doing a lot of modulation keeps a modulation-neutral state for the
plug-in around (updating it when the user makes a persistent parameter
change), and makes sure that the neutral state gets persisted.
C) non-stateful, additive parameter-modulation events for
otherwise-stateful parameters are potentially useful, and should be
considered as a requirement.
D) ... something else?
My thinking is that C is the best solution from the user point of view
(it does increase plug-in complexity slightly, but it's something that's
easily hidden by an SDK baseclass); A is the simplest to implement but
may result in extra parameters and complexity being exposed to the
end-user (bad!); B is good for the user and the plug, but is likely to
be a headache to implement on the host side, and a far worse breeding
ground for bugs than A or C.
Best regards,
Angus.
--
=========================================================
Angus F. Hewlett, Managing Director (CEO)
FXpansion Audio UK Ltd - http://www.fxpansion.com
Registered in the UK - #4455834 - VAT: GB 798 7782 33
=========================================================
----------------------------------------------------------------------
Generalized Music Plugin Interface (GMPI) public discussion list
Participation in this list is contingent upon your abiding by the
following rules: Please stay on topic. You are responsible for your own
words. Please respect your fellow subscribers. Please do not
redistribute anyone else's words without their permission.
Archive: //www.freelists.org/archives/gmpi
Email gmpi-request@xxxxxxxxxxxxx w/ subject "unsubscribe" to unsubscribe
Other related posts:
