I wanted to try drawing a polygon in a way that it can determine where its outline is.
I was hoping to able to draw some pattern and have it fade out near the edges.
But … the corners don’t really work. I guess this is really about distance fields, where I’ve experimented along these lines before, and failed. The white wedges that extend towards the corner are a sign that the distances at the corners are wrong. I had forgotten that I had failed in this exact same way.