Re: [Gimp-developer] [Demo] Porting MyPaint brush engines to the GIMP.

["David Gowers (kampu)" <00ai99 gmail com>]

Hi Liam,

On Tue, May 1, 2012 at 9:52 AM, Liam R E Quin <liam holoweb net> wrote:
> On Mon, 2012-04-30 at 13:05 +0200, peter sikking wrote:
> [...]
>> > 4. Its implementation is very simple and well designed. This is the
>> > most important things for developers!
>>
>> ...but one million users do not care.
>
> They do if people stop working on GIMP.
>
> So, there are several parts here.
> (1) the user experience;
> (2) the technology (the C/C++ library) and how easy it
>    is to maintain and enhance;
> (3) the API between GIMP and the technology.
>
> I don't think there's any question that the mypaint brush editor user
> experience could easily be improved. Heck, it would be improved by
> having some categories, whether as tabs or just headings/groups --
> colour, shape, opacity, motion, and so on.
This is already the case. And I find it does make things much easier
to deal with.

>
> I also don't think GIMP's brush interface is perfect. It's a lot better
> than it used to be, but it's still not very streamlined.
Yes, they both suffer from the difficulty of providing ready access to
all those different curves. Even though the MyPaint approach of
showing all the curves for an output at once is greedy of screen
space, I find it more usable than GIMP's one-curve-at-once approach.

>
> It's for sure true that painting in GIMP is slower than it used to be.
> Clearing the Undo History every now and then gives a dramatic speedup,
> at least with the older 2.7 preview I'm using, and profiling suggests
> there's an O(n^2) list insertion going on, although it's hard to
> understand why that shouldn't be a matter of microseconds, not a
> noticeable fraction of a second.
Yes, GIMP is definitely weak compared to MyPaint WRT both painting
performance and painting quality/ expressiveness.

>
> The gimp brush outline rendering-in-the-idle-loop also makes painting
> _feel_ much slower than it is.
I'd still like it if we could get some kind of very simplified outline
drawing. (say, 8 points -- the most distant pixels from the center
where alpha > threshold, along each of the right angles and 45degree
diagonals). Then, we could use the simplified version during drawing,
and the full version during 'hovering' (before the button is
depressed)

>
> I remember dealing with this in the past in another application by
> discarding motion events if the pointer got too far behind. It meant
> that the drawing became less accurate, but once the pointer outline
> isn't where you're drawing, there's no accuracy in any case.

.. Is that really true? (eg. with a tablet)

>
> Getting a shared core with MyPaint might be really interesting - and the
> user interface doesn't need to be the same in both programs.
>
> Liam
>