Patch for smudge

[JL VT]

I didn't want to double post but it happened!

On Thu, Sep 23, 2010 at 9:34 AM, JL VT <pentalis at gmail.com> wrote:
> On Thursday 23 September 2010, cberger at cberger.net wrote:
>>Rereading your patch, I notice you did not exactly followed my suggestion on
>>IRC :) To make things clear, I have made a patch that does what I suggested.
>>
>>It has decent smudging (I didn't compare it with previous code), it smudges
>>transparent pixels. But there is a square block bug, when drawing on
>>transparent pixels (as can be seen in [1]).
>>
>>I let you investigate the block stuff :)
>>
>>[1] http://cyrille.diwi.org/tmp/krita/smudgetest.png
>
> Clever patch!, but it is somewhat equivalent to the old smudge op
> behavior, and there's gray/black smudges present too. It still
> presents the problems Animtim describes in his bug report:
>
> https://bugs.kde.org/attachment.cgi?id=51647
>

NEVER MIND

I just tested Lukas's patch again, and it displays the same problem
animtim reported when using the normal composite op, just like
Cyrille's patch.

However, when using the copy composite op, both Lukas's patch and
Cyrille's patch achieve the effect desired by animtim.

Table1: tabulated results for animtim's request
(https://bugs.kde.org/attachment.cgi?id=51647):
============================
Version: (composite op) result; (composite op) result; etc.
-------------------------------------------------------
Trunk: (normal) bad, increases opacity; (copy) bad, decreases opacity.
Lukas's patch: (normal) bad, increases opacity and black smudges;
(copy) good but with white square artifact on the right side of the
dab.
Cyrille's patch: (normal) bad, increases opacity and black smudges;
(copy) good but with white square artifact on the right side of the
dab.
============================