Pixels are misaligned on Quartz/Cocoa rendered canvas

Number:rdar://FB10511386 Date Originated:2022-06-30
Status:open Resolved:
Product:macOS Big Sur Product Version:11.6.6
Classification:Rendering Bug Reproducible:Yes

- macOS 11.6.6 Big Sur
- MacBook Pro Retina 15" (Mid 2014)
- NVIDIA GeForce GT 750M 2 GB
- GraphicConverter 11.6.1 and newer

## BUG

- GraphicConverter: Pixels on canvas are misaligned https://www.lemkesoft.info/forum/viewtopic.php?t=6756
  - Was detected in GraphicConverter 11.6.1 in 2022-04-07, an continues until the latest releases now in 2022-06
  - According to the developer Thorsten Lemke: Zooming & panning on canvas uses standard Apple Quartz/Cocoa calls.

- The bug reporter (me), the developer and volunteering community members tried all possible configurations:
  - It always works fine on newer Macs.
  - And it just never works on the affected Mac (see stated specs).

- The developer has high certainty that this is a bug in the graphic drivers on macOS Big Sur for the given NVIDIA GPU series.
  - I feel that not to hard to believe as I also reported FB9001334, which is very different in nature but also a severe GPU/compositing glitch for sure.
  - Interestingly in Preview.app on the same machine zoom&pan has perfect alignment.

I know my rMBP (Mid 2014) is a legacy machine meanwhile.
- Please tell me upfront whether you have incentive to look into this at all.
- or whether it is a known problem.
- I appreciate every small reply that I get.


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