Last night I started working on a wmutil opt program for bevel borders. I was inspired by seeing vain's setup and shot him an email awhile back. He linked me his dwm implementation, which was very helpful. Thanks to the comments there I learned about how you have to set your pixmap for window borders, which was very helpful for understanding why the existing chwb2 had it's rectangle setup up like this.

A bevel by my planning is essentially a triple border that changes color halfway through on the inner and outer borders. Using some graph paper I set the calculations for what rectangles to draw after being moved into correct position. image.

I need to go over those again because it's not quite accurate (and assumes border width of 8 for testing) but current appearance: https://u.teknik.io/WPGnV.png

code: https://github.com/neeasade/opt/blob/master/chwbb.c

edit: woo https://u.teknik.io/7v8h2.png