Subject: Re: [linux-audio-dev] LADSPA GUI Issues
From: David Olofson (david_AT_gardena.net)
Date: la maalis 11 2000 - 20:50:30 EST
On Fri, 10 Mar 2000, Richard W.E. Furse wrote:
> It MIGHT well be worth setting up a GUI API for LADSPA plugins for X-Window
> if there is a consensus on how this should be done. Because of the variety
> of graphical toolkit out there I suspect we might be better off leaving
> this for the moment, but if people can agree on a common standard that
> would be very cool. Even so, I'd like to avoid clouding the issue too much
> with LADSPA and for the GUI API to be separate.
I don't think the GUI API itself should be a part of the plugin API,
or an extension to it. With LADSPA, this gets a bit complicated, be
the MuCoS event system and the client/server model would bring this
in for free; just use the plugin API for the GUI modules.
> Issue (2) above is not resolved as of Alexander Konig's post. As he pointed
> out, the host currently has no way to determine suitable ranges for sliders
> etc when generating a PVR automatically. This could be got around by just
> giving the user a textbox and hoping they'll get on with it, but I don't
> think that's terribly nice. One option is to include an optional 'suggested
> range' for each port and perhaps a 'toggle' port property. (Much as posted,
> although I prefer the idea of toggles being off if <=0 and on if >0 - this
> allows clever things to be done by connecting control LFOs to toggle
> control switches etc.) Note that this is only a *suggested* range. The
> plugin is expected to accept ANY value as in fact the user may have plugged
> in a control signal rather than entering a value (depending on host
> behaviour) and will be rather annoyed if the entire application then
> explodes. I've mixed feelings about all this - what do other people think?
I have mixed feeling too, as you might have noticed in some earlier
post...
I think it's a good idea to have "soft" ranges, but I still think
that the "recommended" range should be somewhat standardized, so that
a wildly experimenting user can see some similarity in how different
inputs react to certain input values or signal. Perhaps signed,
unsigned and possibly switch (really just signed, but without max/min)
is enough? That is;
Signed:
-1.0 <= value <= 1.0
Unsigned:
0.0 <= value <= 1.0
Switch:
< 0.0 ==> Off
>= 0.0 ==> On
Then, it could be nice to know if a plugin really limits values to
within the standard ranges or not, but that's probably of little
interest to the host.
//David
.- M u C o S --------------------------------. .- David Olofson ------.
| A Free/Open Multimedia | | Audio Hacker |
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