# Objective
- Fixes#13503
- Fix other various bugs I noticed while debugging above issue.
## Solution
- Change the antialiasing(AA) method. It was using fwidth which is the
derivative between pixels, but there were a lot of artifacts being added
from this. So just use the sdf value. This aa method probably isn't as
smooth looking, but better than having artifacts. Below is a
visualization of the fwidth.

- Use the internal sdf for drawing the background instead of the
external sdf and extract the border for these type of nodes. This fixed
2 bugs, one with the background coloring the AA pixels on the edge of
rounded borders. And also allows for the border to use a transparent
color.
- Don't extract borders if all the widths are zero.
## Testing
- played a bunch with the example in the linked issue.
This PR:

Main:

- ran the `borders` and `rounded_borders` examples
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## Changelog
- Fixed various antialiasing issues to do with rounded ui borders.
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Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Andreas Weibye <13300393+Weibye@users.noreply.github.com>