Subject: Re: [linux-audio-dev] Plugin GUIs
From: David Olofson (david_AT_gardena.net)
Date: Sun Mar 25 2001 - 18:38:36 EEST
On Sunday 25 March 2001 00:37, Paul Sladen wrote:
> > I have used my own simple renderer so far but if anyone has a
> > real 3D renderer/modeler and some design skills, I would not mind
> > if a common LAD GUI design is made: buttons, knobs, panels, LEDs,
> > displays, etc.
>
> [At the risk of starting a flame bate...]
>
> What about standardising on GTK+ for the GUI layout -- Even going
> to the point of just loading in `glade-xml' definitions of the
> interfaces. So you say: "won't this bind us to a particular widget
> set?". I say this, considering that most appear (I think!) are
> building/standardising around GTK.
>
> As has been shown with the GIMP; it's had really worth writing a
> Widget Abstraction layer on top of another Widget Abstraction
> layout; port the Widget set instead!!.
Right; it's just that the "porting" will also have to involve
completely changing the feel of the toolkit to fit in with the native
toolkit of the target platform. It's not very obvious with X where
we're used to the fact that there's no bl**dy standard at all, but I
wouldn't say GIMP behaves very well under Win32... (It's also very
much slower than the X version, and very much slower than for example
PhotoShop. Hopefully an event management implementation issue.)
Then again, in this particular case, no one cares about native look
and feel anyway; it's not even desired in most cases!
> When (IF?) you support LADSPA-GUI on other platforms; then the
> Widget set is probably already ported; or; how much trouble would
> it be to write an import filter to translate the glade-xml
> definition on loading?
>
> [Or am I missing the point?]
I don't think so, but I'm not sure GTK+ is the right tool for the job
if we don't want GTK+ look and feel anyway. There are simpler
toolkits that are *much* faster - and if we aren't going to use
standard widgets and GTK+ rendering engines anyway, why drag all that
in?
I'm worried about the overhead - GTK+ feels sluggish on all but the
fastest of my machines... Is a G400 MAX video card really supposed to
be a reasonable low end requirement!?
Either way, it would probably be a good idea to reuse whatever can be
reused, rather than rewriting it all from scratch yet another time.
(Of course, that is assuming that it isn't the layout engine that's
slowing GTK+ down. I don't know enough about the inner workings of
GTK+ to tell what's going on...)
> > Note: the images should be large (512x512?) and the final pixmaps
> > would be resized in the application whenever user wants to resize
> > GUI elements. Besides having suitable sized GUI elements, it
> > would be advance to be possible to make often used GUI elements
> > larger.
>
> Um, is it really nessecary to store 1 *megabyte* of pixmap *per*
> `icon'. (512*512*RGBA -- 2^(9+9+2) == 2^20)?
Well, if we're going to scale *raster* images without ending up with
blurred or jagged results; yeah, you can't go much lower than about 2
or 3 times the biggest target sive with interpolated stretching. It
might work better with windowed sinc based scaling or something, but
the best I've ever seen on a graphics accelerator is quadratic
interpolation. Most cards (including all of the current
top-of-the-line 3D gaming accelerators) use linear interpolation.
Oxygen or Wildcat, perhaps? ;-) (You can't even fit the latter in a
normal workstation, due to special cooling requirements. It burns 110
Watts...)
Right, the scaling doesn't need to happen in real time, but this is
probably heavy enough that loading the average plugin GUI will take
several seconds on a Pentium class machine. A 2D vector format with
texturing support might be more efficient - but also a lot more
complicated.
//David
.- M A I A -------------------------------------------------.
| Multimedia Application Integration Architecture |
| A Free/Open Source Plugin API for Professional Multimedia |
`----------------------> http://www.linuxaudiodev.com/maia -'
.- David Olofson -------------------------------------------.
| Audio Hacker - Open Source Advocate - Singer - Songwriter |
`--------------------------------------> david_AT_linuxdj.com -'
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