Affinity/XP-Pen Compatibility Issue

[ChristiduToit]

Potential compatibility issues with the latest XP-Pen driver and Affinity apps (just posting in the Photo forum as this is where I noticed it first).
After installing the latest update I've noticed that the strokes I make using the brush tool (or any tool for that matter) result in jagged lines - attached a screenshot below.
The further I zoom out of my canvas the worse it gets, almost as if the lines start snapping to an invisible 90 and 45 degree grid, or as if the resolution decreases the more I zoom out. 
I'm using a late-2015 iMac running macOS Big Sur Version 11.1, and the tablet I'm using is the XP-Pen Artist 22R Pro.

I would have assumed this was an XP-Pen issue, however, the tablet seems to be working perfectly in other apps.

I've brought this same issue up in the past, it was then resolved in an Affinity update, but now it seems to be back with a vengeance - really hoping there's a fix in 1.9!
Here are the previous posts I'm referring to:

1. https://forum.affinity.serif.com/index.php?/topic/85155-by-design-aliasing-issue/

2. https://forum.affinity.serif.com/index.php?/topic/93763-whole-pixels/

[Gabe]

Hi @ChristiduToit,

I can't replicate it that bad here with an XP Pen Artist 12. 

Comparing 10% with 100% will not be relevant. At 10% you have a lot less surface area to draw the same length, so it is expected to have jittery lines. I don't know how good your 22R, but this Artist 12 is so bad. I have the Deco 3 which works fine, but the Artist I have it's unusable. 

Any chance you can do a screen recording at all? Perhaps we can see more clearly what's going on. 

[ChristiduToit]

Hi @Gabe
I've gone ahead and uploaded a screen recording - apologies for the bad audio:

It's difficult to explain exactly what this bug is doing, but, as I mentioned, it seems as if Affinity is lowering the canvas resolution when I zoom out.
Almost as if the screen pixels are not zooming out along with the canvas, so even though my canvas might be at 10%, the app is registering the tablet input as if it was still zoomed to 100%.
I've attached another screenshot below which might help explain what I mean a bit better.

[Gabe]

Thanks. Issue logged. 

[ChristiduToit]

@Gabe Thanks a mill! Hopefully my little diagram/example wasn't too confusing.

Just to add to this, I'm sure you've probably noticed this too, a lot of people on the forums, elsewhere online, and even in real life, have mentioned that Affinity's brushes don't 'feel' as accurate, smooth, and buttery as some of the other desktop drawing apps like Photoshop and Clip Studio Paint. A lot of other illustrators and digital artists I know have actually pointed this out as one of the primary reasons why they don't use Affinity for desktop for their work and still stick to Adobe. I have a pretty good hunch that the root of those issues lie with this same problem. It's been noticeable from the day I started using Affinity, I suppose I've just gotten used to it. It seems to have improved slightly with updates, but is not fixed altogether. I truly believe that figuring this out, and fixing the reason why this is happening, will make Affinity app's a lot more appealing to a much wider audience and a lot more competitive in the marketplace. To affirm this, Clip Studio Paint's perfectly precise/accurate and buttery smooth brushes are one of their main selling points and a lot of people use it over Photoshop for that exact reason.