Add workaround for subpixel rounding

[hrjakobsen]

Why

This is a workaround, and very much a request-for-comments if you can come up with a better idea

After merging #12 yesterday, I've noticed that the Firefox subpixel rounding removes the marker at some font sizes / marker width levels.

What changed

I think it happens since 1ch is a fractional value, hence the browser will have to do some rounding in the repeating pattern. What I cannot answer, however, is why this rounding sacrifices the 1px marker rather than the heap of transparent content right next to it.

The solution to add a little bit of "padding" to the marker is not great, but it's the best I could come up with that seemed to fix in all of my test cases.

Sorry for not catching this in yesterdays PR.

Before:

After:

[sergeichestakov]

weird. is this issue only present on Firefox? im not sure I noticed it

[hrjakobsen]

weird. is this issue only present on Firefox? im not sure I noticed it

I think so, yeah. My colleague didn't notice it happening on Safari at least.

[sergeichestakov]

hmm which OS are you using? I'm on Firefox as well on MacOS and not seeing it

[hrjakobsen]

firefox -v  
Mozilla Firefox 111.0.1

uname -a
Linux 5.19.0-35-generic #36~22.04.1-Ubuntu Fri Feb 17 15:17:25 UTC 2 x86_64 x86_64 x86_64 GNU/Linux