Bug 420742 - Drawing with Grid snap and Line tool not intuitive
Summary: Drawing with Grid snap and Line tool not intuitive
Status: CONFIRMED
Alias: None
Product: krita
Classification: Applications
Component: Tools (show other bugs)
Version: nightly build (please specify the git hash!)
Platform: Neon Linux
: NOR minor
Target Milestone: ---
Assignee: Krita Bugs
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2020-04-29 08:36 UTC by Alexey
Modified: 2025-04-28 20:36 UTC (History)
4 users (show)

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


Attachments
Grid snap and Line tool draw non intuitive (1.70 MB, video/mp4)
2020-04-29 08:36 UTC, Alexey
Details

Note You need to log in before you can comment on or make changes to this bug.
Description Alexey 2020-04-29 08:36:22 UTC
Created attachment 127978 [details]
Grid snap and Line tool draw non intuitive

If we enable grid snapping and use the line tool, the result may not be linear, but may shift above or below the grid line. It depends on the start and end point of the line line, it is confusing.


STEPS TO REPRODUCE
1. Enable grid snap
2. Take a Line tool
3. Draw a line beside grid line like on video (same with and without Shift)

OBSERVED RESULT
Shifted line


EXPECTED RESULT
Straight line

SOFTWARE/OS VERSIONS
All

ADDITIONAL INFORMATION
This is necessary in pixelart
Comment 1 konstantin 2020-04-29 08:39:34 UTC
Yes, I have such a problem. I would like a straight line, but it is not a straight line :) It will be cool if you fix it.
Comment 2 Tiar 2020-04-29 11:35:35 UTC
There is a video and two users with the same problem, so let's set it to confirmed.
Comment 3 Ahab Greybeard 2020-04-29 14:41:06 UTC
The line tool will only snap to the grid when it's very close to a grid line or intersection. It would be nice if this 'sensitivity' or 'snappiness' had a slider control of some kind.

The grid line itself is on the border of rows/columns of pixels and so at pixel art scales you can't snap onto the grid line, you snap onto the nearest image pixel.
Comment 4 Vitamorus 2025-04-28 19:12:47 UTC
Re-confirming this for Krita 5.2.9.

Grids and snapping definitely could do with some love in general:

- Actual adherence to the grid is a bit hit and miss. On raster layers, the Line Tool appears to suffer from what looks like possible rounding errors, causing slight diagonals (possibly what konstantin was referring to) . The Freehand Path Tool I can't seemingly get to follow the grid at all.
- As suggested by Ahab, some sort of snapping sensitivity setting wold be welcome
- A clearer indication where the line/painting operation is being snapped to on the grid would be helpful. For example, the brush outline could be shifted over to that location on the grid. 
- Other suggestions would be to extent the snapping to the Freehand Brush Tool and looking into the possibility of snapping to an isometric grid (does the isometric grid really need precision to 4 decimal places btw?)

There's also a minor rendering bug of the grid in rectangle mode, seemingly caused by the brush outline. When moving the cursor over the grid with a tool that shows the brush outline it will sometimes cause parts of the grid to disappear.
Comment 5 Vitamorus 2025-04-28 20:36:23 UTC
Looks like the grid rendering bug is fixed in the 5.3 pre-alpha (good thing I didn't make a separate report for it) :)