Bug: Offset while using brush tool on iPad

[snskar]

Description

• Large offset while using the web version on iPad.
• Using the apple pencil to draw with the brush tool on the iPad surface, there is a large noticable offset of the ink appearing from the tip of the pencil touching the screen.
• The brush ink also flows outside of the artboard (although I suspect this might be by desgin)

Video Demonstration

https://drive.google.com/file/d/1buYIvX035Be9K-pn0Rn7eCGvYZ4jJTX1/view?usp=sharing

Other details

• Safari version: 26
• iOS version: iPadOS 26.0
• iPad model: iPad Pro 13 inch, 2024

Preliminary thoughts

• The mismatch is CSS px vs device px and/or origin differences.
  look at https://github.com/GraphiteEditor/Graphite/blob/master/editor/src/messages/tool/tool_messages/brush_tool.rs

[Sambhram1]

tried to slove this issue #3305

[ManavMehta2312]

I’d like to try working on this issue. It looks like the brush offset might be caused by a difference between the iPad’s screen coordinates and how the app reads them.

I’ll start by checking the brush_tool.rs file to understand how the pointer position is handled. Please let me know if there’s anything specific I should look at or test.

[Keavon]

@ManavMehta2312 you should reference the conversation in the issue linked in the comment above yours.