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

[Michael Natterer <mitch gimp org>]

On Mon, 2012-04-30 at 19:29 +0900, sigetch wrote:
> 2012/4/30 Alexandre Prokoudine <alexandre prokoudine gmail com>:
> > On Mon, Apr 30, 2012 at 1:13 PM, gfxuser wrote:
> >
> >> What makes these brushes different to the GIMP brushes with 2.8 dynamic
> >> options?
> >
> > It's more options that makes it :)
> >
> > Install MyPaint and have a look at the advanced options dialog. You'll see it.
> >
> 
> MyPaint brush engine has three four advantages:
> 
> 1. Its back-end has simple "replace-alpha" operations. Current
> paint-brush has no such operations. (Only some tools like smudge tools
> has such operations.)
> 
> 2. It has 9 inputs, 42 setting parameters, and 30 internal states to
> determine the timing, position, size, color, and blend mode. while the
> dynamics has 7 inputs, 11 setting parameters, and no internal states.
> MyPaint brush engine can produce more various output.
> 
> 3. All parameters are defined as brush parameters, while in gimp,
> those parameters are not managed in one object,  brush dynamics and
> tool options manages some of those parameters.
> 
> 4. Its implementation is very simple and well designed. This is the
> most important things for developers!

I haven't looked at the code yet, would you mind to come
to #gimp on irc.gimp.org to talk about the implementation?

> 
> And It has some disadvantages:
> 
> 1. Currently its core supports ellipse dab mask only. (That means no
> pixmap brushes.)
> 
> 2. It only supports "incremental" painting mode.
> 
> 3. It lacks paint mode at all. (But who uses the painting mode of the
> paint brush?)

That sounds like you wrote a completely new paint core for it?
Or did you just subclass GimpPaintCore, avoiding GimpBrushCore?

You must use some standard way of applying the paint to the
drawable, which is most likely gimp_drawable_apply_region()?
It's probably no problem to get layer modes there.

I should actually look at the code :)

Regards,
--Mitch