Bug 389770

Summary:	Transparency mask after layer transformation
Product:	[Applications] krita	Reporter:	Dmitrii Utkin <loentar>
Component:	Filter Layers	Assignee:	Krita Bugs <krita-bugs-null>
Status:	RESOLVED INTENTIONAL
Severity:	minor	CC:	halla, raghu
Priority:	NOR
Version First Reported In:	4.0.0-beta.1
Target Milestone:	---
Platform:	Appimage
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Dmitrii Utkin 2018-02-01 20:23:33 UTC

This is not a serious problem (if it's a problem at all) but quite annoying.

When you have a layer with transparency mask and then apply a transformation using transform tool, the region on mask where old raster was lying become fully transparent (black). This is discouraged because when you try to draw over the old region, you see nothing - mask makes it fully transparent. Ire-fill that region with white (when I forgot to lock the mask)

Can you consider to fill the old region with opaque (white)?

Here is a small screencast for the problem:

https://drive.google.com/file/d/1BYuoauxa69OgqKag44aKC57OhQyxBIz9/view?usp=sharing

Comment 1 Raghavendra kamath 2018-02-03 19:02:37 UTC

I know this is an annoyance but it is also how the mask works.

A mask has not alpha channel so anything to you erase or delete will be filled with black . For example if you use eraser brush over the transparency mask it will fill it with black. So in that sense when you transform the layer, the transparency mask also gets transformed and in-turn the place that gets shifted leaves a transparent region which gets converted to black in the transparency mask.

Making it fill white would break the erasing behaviour I think, how would it know that the part is erased from a transform and not erasing.

Comment 2 Dmitrii Utkin 2018-02-04 07:52:59 UTC

Thank you for response,

I understand the technical complexity, but it is really inconvenient how it works now. You have to switch to the mask and re-fill the emptied region. When you do complex transformations, you have to repaint the whole mask, because it become impossible to fix. This involves more time to complete the work.
Often when developing software you have to write exceptions and hacks for some scenarios to make software work smoothly for the end user (at least this is my experience of developing software for the last ten years :).

Well.. if it's not possible at all or too much work to to fill the cleaned area with opaque, it's still usable. Thanks again.

Comment 3 Halla Rempt 2018-06-20 21:51:09 UTC

I'm sorry, but this is just the way maths and stuff works -- there isn't anything we can do about it.