Bug 347874 - Drawing area flashes random section of the alpha layer
Summary: Drawing area flashes random section of the alpha layer
Status: RESOLVED WORKSFORME
Alias: None
Product: krita
Classification: Applications
Component: Layer Stack (show other bugs)
Version: 2.9.4
Platform: Microsoft Windows Other
: NOR normal
Target Milestone: ---
Assignee: Krita Bugs
URL: http://postimg.org/image/dhpijr197/
Keywords:
Depends on:
Blocks:
 
Reported: 2015-05-18 02:28 UTC by Ricky
Modified: 2020-06-09 04:33 UTC (History)
2 users (show)

See Also:
Latest Commit:
Version Fixed In:
Sentry Crash Report:


Attachments
Screenshot (53.73 KB, image/jpeg)
2018-01-24 11:15 UTC, Halla Rempt
Details

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Description Ricky 2015-05-18 02:28:56 UTC
OS: Windows 7 64-bit
CPU: AMD A8-6410 APU with AMD Radeon R5 Graphics (4 core), ~2.0GHz

When I have a canvas open on Krita, there is this small block that does not render.
The non-rendering spot (from now on will be referred to as "square") is not fixed on a specific point on the canvas, but instead seems to be on a fixed point relative to the window of the editing field.
However, the square only shows up on top of the canvas.  If the spot that the square would show up is off of the canvas, it won't show.

I believe it has to do with how the editing window is being rendered and nothing to do with the canvas at all.  The reason why I suspect this is because the transparency squares that shows within the "square" is smaller than the transparency squares shown from the canvas' alpha (when all the layers in a spot are invisible).

I was lucky enough to be able to catch a screenshot of said issue.  The image is uploaded at the URL posted.  You can see what I am talking about top-right from the center of the screen.  It always happens at the same spot no matter where the canvas is positioned on the window.

PLAUSIBLE CAUSES:
1.) My primary (and currently only) idea on what is causing this is data is somehow getting lost or not even calculated on that tile set.  It is always at the same spot and at the same size.
In fact, the exact position of the square is at 28, 7 in "square" units using OpenGL's coordinate system (top-left oriented instead of the typical bottom-left).  It isn't "exactly" that, but the offset on the x and the y are the same.
You can see an example of this at http://postimg.org/image/6gfncsga5/

If the issue's actual source is still unknown by Wednesday, I will download the source code and try to find the issue.  I really like what is being done here and I would very much like to contribute and see it succeed.


Reproducible: Always

Steps to Reproduce:
Simply load a canvas (either new or pre-existing) onto Krita.

Actual Results:  
(As Described Above)

Expected Results:  
For that transparency spot to not flash in and out.

I kind of already put all of my information that I find relevant in the Details section.
Comment 1 Halla Rempt 2016-03-19 19:01:14 UTC
Hi Ricky,

Sorry for the late reply! This very much looks like opengl corruption, as you say, but the weird thing is, it isn't something that happens for many people, so I'm inclined to look for a cause in your system. Can you check whether this still happens with 3.0 pre-alpha 3?
Comment 2 Halla Rempt 2016-06-16 09:41:53 UTC
Hi,

I've seen this happen now. I'm pretty sure there's already another bug for it, but I cannot find it.
Comment 3 Halla Rempt 2018-01-24 11:15:32 UTC
Created attachment 110091 [details]
Screenshot
Comment 4 wolthera 2020-05-10 12:46:53 UTC
Is this still relevant? I think we rewrote the canvas code another seventy times since this report ;)
Comment 5 Bug Janitor Service 2020-05-25 04:33:11 UTC
Dear Bug Submitter,

This bug has been in NEEDSINFO status with no change for at least
15 days. Please provide the requested information as soon as
possible and set the bug status as REPORTED. Due to regular bug
tracker maintenance, if the bug is still in NEEDSINFO status with
no change in 30 days the bug will be closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

If you have already provided the requested information, please
mark the bug as REPORTED so that the KDE team knows that the bug is
ready to be confirmed.

Thank you for helping us make KDE software even better for everyone!
Comment 6 Bug Janitor Service 2020-06-09 04:33:08 UTC
This bug has been in NEEDSINFO status with no change for at least
30 days. The bug is now closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

Thank you for helping us make KDE software even better for everyone!