Bug 504551

Summary:	Vector rasterizer creates half-transparent pixels on vector shapes without gaps whose borders are not on pixel boundaries
Product:	[Applications] krita	Reporter:	Katalin Rebhan <me>
Component:	Layers/Vector	Assignee:	Krita Bugs <krita-bugs-null>
Status:	REPORTED ---
Severity:	normal
Priority:	NOR
Version First Reported In:	5.2.9
Target Milestone:	---
Platform:	macOS (DMG)
OS:	macOS
Latest Commit:		Version Fixed In:
Sentry Crash Report:
Attachments:	Example.kra

Description Katalin Rebhan 2025-05-20 00:00:35 UTC

SUMMARY
Having two vector shapes (e.g. rectangles) next to each other can create transparent pixels between them despite the two shapes being flush next to each other, if the border between them is not on a canvas pixel boundary.

STEPS TO REPRODUCE
1. Create a vector layer with two rectangles next to each other
2. Resize/move the rectangles so that the border between them is not on a pixel boundary

OBSERVED RESULT
The rasterizer outputs half-transparent pixels on the border between the two rectangles

EXPECTED RESULT
The pixel on the borders is colored proportionally according to the percentage the two shapes fill out

SOFTWARE/OS VERSIONS
macOS: 15.5 (24F74)

ADDITIONAL INFORMATION

Comment 1 Katalin Rebhan 2025-05-20 00:01:59 UTC

Created attachment 181547 [details]
Example.kra

Here's an example file demonstrating the issue. On the right image, which is just a copy of the left image resized, the pink background should not be visible through the white/gray squares, since they do not have a gap between them.