We had been doing a pretty good job of scaling the user interface as users change the display resolution size in Preferences.
However, with 2.8 (I think) we gained the ability to also change Line Width and choose thick lines. I believe the intent was for drawing thicker lines inside the 3D viewport. But it affects all lines all over the interface. And I am wondering if we are keeping that behavior.
A question like this might seem to have an easy answer: “hell, yes!” But it does mean more work all over. Right now choosing “Thick Lines” is causing “off by a pixel or two” errors all over the place.
In the interface code it is pretty important to know how big things are. The following button, for example, is 20 pixels wide when the scale is set to “1”. In the code this button is exactly one “UI_UNIT_X” wide and it is that variable that changes as the user scale changes.
But to properly get the size of this button to account for differing line widths we’d have to instead consider it to be 0.9 of a “UI_UNIT_X” plus two times the line width. This is because thin lines are one pixel wide, and thick ones are two, regardless of interface scale. So this complication of calculation would have to be done all over the place.
Just asking for a friend… LOL