Scaling introduces stepping to gestures and GTK applications
I checked but couldn't find a previous issue about this, apologies if this is a duplicate.
With a scale factor greater than one, the smallest step size when performing a gesture in Phosh or in a GTK3/4 application is equal to the scale factor. User inputs are properly converted to floating point types and scaled down with fractional components, but the calculated margins, offsets and surface positions in Phoc seem to all be stored as integer types, cutting off the fractional part, these values are then scaled back up before rendering. Comparing side by side to Android on the same device (same kernel version and similar mesa), the differences are a lot more noticeable.
Both of these videos were recorded at 4x scaling to make the effect more visible. This is a side-by-side with Android for reference (you'll have to forgive the Android stutters, that's a different issue entirely...):
Here's a closeup of the notification drawer being opened: