Bug 419282

Summary:	Pixel Art brush Grid Locking
Product:	[Applications] krita	Reporter:	John Angelo Tenorio <john.angelo.tenorio>
Component:	Brush engines	Assignee:	Krita Bugs <krita-bugs-null>
Status:	RESOLVED FIXED
Severity:	normal	CC:	halla, lynx.mw+kde, tamtamy.tymona
Priority:	NOR
Version First Reported In:	4.2.9
Target Milestone:	---
Platform:	Manjaro
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description John Angelo Tenorio 2020-03-27 05:32:18 UTC

SUMMARY

Pixel Art brush cursor Locks into Pixel Grid. Looks and feels unresponsive to tablet strokes when using freehand drawing. Leads to inaccurate drawing when using Free Hand Brush Tool.

STEPS TO REPRODUCE
1. Use the default "u)_Pixel_Art*" brushes
2. Move the pen/mouse around the canvas using Freehand Brush tool.
3. Draw using Freehand Brush tool.

OBSERVED RESULT

Brush Cursor locks into pixel grid and does not accurately respond/move with pen strokes resulting in inaccurate freehand drawing.

EXPECTED RESULT

Center of brush cursor should be in center of pointer and moves with pen.

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: Manjaro 
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION

Comment 1 Halla Rempt 2020-03-27 08:58:58 UTC

I'm sorry that you don't like this, but it's intentional. See https://bugs.kde.org/show_bug.cgi?id=407405 and the following commit:

If you want to avoid things like this, you'll have to participate in the discussions that drive Krita's development and test nightly builds and beta's.

commit 9a972eea69526311cd95dd45335d2f1ba7d24fc3
Author: Ivan Yossi <ghevan@gmail.com>
Date:   Wed Dec 4 07:51:59 2019 +0000

    Fix 1px brush offset in line tool
    
    This adjust the diferent position of KisPaintInformation
    from a line to be inside a line between starting and
    ending points. This is particularly important as brushes
    that use 1px perfect pixels require the line to be perfect
    in order to avoid looking jagged. In 1px size with
    sharpen active we only use the start and end
    KisPaintInformation points.
    
    This patch also adjusts the outine on 1px brushes to
    adjust to the grid to better preview where the paint is
    going to be applyied
    
    BUG:407405
    (cherry picked from commit b434751233e91d229617952bb73ca0744353bd10)

Comment 2 Tiar 2020-03-27 12:01:54 UTC

Relevant reddit thread: https://www.reddit.com/r/krita/comments/fp7xaq/pixel_art_brush_cursor_pixel_lock/flkk0d1/?utm_source=share&utm_medium=web2x

Relevant parts of the irc conversation:
[19:41:41] <dmitryK|log> tiar: and what about that pixel-art bug?
[19:42:13] <tiar> dmitryK|log: not sure if it's a bug, but certainly a complaint. https://www.reddit.com/r/krita/comments/fp7xaq/pixel_art_brush_cursor_pixel_lock/flkqal6/?context=3
[19:42:53] <dmitryK|log> tiar: the screenshot looks really buggy
[19:43:43] <tiar> dmitryK|log: should I tell them to file a bug report?
[19:44:07] <rebecca2525> buggy how?
[19:45:05] <ivanyossi|log> rebecca2525: the outline should be on the pixel grid not inbetween the pixels.
[19:46:12] <rebecca2525> Oh, I was looking at the wrong screenshot
[19:50:45] <Lynx3d> hm I cannot reproduce the pixel brush outline not matching the pixel grid, but the outline does seem to jump to the next pixel before the brush actually draws there...
[19:54:57] <dmitryK|log> Lynx3d: make sure 1) you activate sharpness; 2) when you click, the brush paints exactly at the place where the outline is
[20:05:12] <dmitryK|log> Lynx3d: did you manage to reproduce the pixel-brush bug in the end?
[20:09:30] <Lynx3d> dmitryK|log, not really, while it's different that the outline now snaps to pixels, I don't have any misalignment, only that the dab draws a bit later than the actual outline jump occurs

Comment 3 Halla Rempt 2020-03-27 12:14:23 UTC

Okay, let's reopen then, though I still think that the new behaviour when sharpen is enabled is actually preferable.

Comment 4 John Angelo Tenorio 2020-03-27 13:15:28 UTC

Relevant bug regarding off-grid cursor: Bug#419283

Comment 5 Lynx3d 2022-05-18 15:19:43 UTC

The controversial snapping behavior is now optional with https://invent.kde.org/graphics/krita/-/merge_requests/1405