[linux-audio-dev] Knobs, the reply

[Thorsten Wilms]

Oh well, just read through the more than 30 mails ...

Thanks to Arnold, Marek, Tim Hockin, Benno, Uwe, Tim Orford 
for the nice words.
Thanks to everyone for the interest.

About a standard toolkit:

The general desktop toolkits do not adress some special needs 
of audio apps, that's clear.

While an integrated look/feel with other, non-audio apps, would 
be nice, it can hardly be achieved (think alone of theming).
Therefor a somewhat alien look could be of advantage (better 
clearly different than somewhat alike).

Unification advantages: write once, get used to once, allowing 
usage to become somewhat subconcious (switching between different 
looks/feels doesn't allow that).

It would be great to have all scalable vector guis (especialy 
interesting options for modular systems, overview vs tuning).
Even without scaling, I think I would prefer to deliver plain 
SVG.

Beside implementations in the major toolkits there's also 
Y at the horizone, with a base collection of widgets that 
is planned to be extendable with modules.

About generating plugin guis from parameter descriptions:
don't forget that layout is important. There would have to be 
some hints for that at least.

I'm working on something very general regarding user interfaces, 
and widgets will be one topic. This should give me a nice 
foundation for an audio toolkit design from the look and feel 
side. So how about building a standard for exactly that: look 
and feel? Who's with me?
About the implementation: wouldn't it be possible to wrap things 
up in enough ways to every capable developers likes?
For people like me it would be more interesting to have gui 
editors / high level descriptions for concentrating on design.
(hand writing xml or similar is acceptible for me, fiddling 
around with c code rather not)


To Rtaylor:
I'm all for breaking away from analog limitations. But I still 
think that a little 3d look helps with making clear what is 
manipulatable and what is not. And I hope it's possible to make 
both purists and eye-candy freaks happy enough (I'm myself more 
on the purist side, being german industrial design student, think 
Bauhaus and all :)
And would you say what I presented is not clear/easy to 
read/decipher?


About advanced knob functionality:

For resetting knob with center (pan) I would rather replace the 
simple line mark with an arrow, that can be clicked for reset.

Mousewhell should work, of course! Backwards decrease, forwards 
increase, to match with scrollbars/sliders. When Ctrl is used 
for finer adjustment, Shift or Alt could boost.

Plus/minus buttons could also work.

Right-click must be preserved for context menus (knobs could 
of course have such).

For numerical input making use of a text field close to the knob  
might be better (but in any case only when numerical exactness 
makes sense).

Tim Hockin: please elaborate about velocity sensitve knobs like 
used by OhmForce.

A special fine adjustment accessible by a non-left click or with 
modifier key is a little problematic, because it breaks the 
connection between scale/indicator and mouse movement (not that 
I'm against it, only wanted to point this out).

Clicks/modifier keys should not be user options. No need for 
extra coding, overloaded preferences / layout problems and 
users fiddling around instead of using the software.


Radial?

For those who think radial is bad: in that case knobs shouldn't 
be used at all! (Tim Hockin: it makes no sense to disagree to a 
half sentence/meaning!) Popping up a slider doesn't help much, 
the nature of the control should be clear right away.
However, I never had problems dealing with radial knobs, but 
always found linear ones do not feel right.
There's no need to move the pointer accurately in circular 
fashion, a soft bow works perfectly fine.

I do not say knobs are perfect / better than sliders 
or other solutions in all cases, and I'm aware of the problems.

Oh, and about linear needing 2 directions, up/down for gain 
and right left for pan (Uwe): Sure. And the widget has 
to be clear about that in advance.



About releasing the knobs

Everybody can have the existing svg, png export or Blender 3d 
files (just ask). I doubt I will continue with Blender, so future 
work will be vector or directly bitmap. Like I said, it's not 
finalized at all.

ATM I do not know how to best generate series of bitmaps 
for rotations. Would be nice if someone could help with a 
little imagemagick or gimp scripting to do the rotation and 
combine it with fixed parts.


Benno:
I think Dave Robillard is right. Only when you're very sure the 
saved space can be put to better use, knobs ar an option there.
And the design would have to be adapted to fit in.


---
Thorsten Wilms