Patch a bunch of corner glyphs into a font.
python3
fontforge
./patch <input-font> <output-file-name>
e4c5
full-top-lefte4c6
full-top-righte4c7
full-bottom-righte4c8
full-bottom-lefte4c9
half-top-lefte4ca
half-top-righte4cb
half-bottom-righte4cc
half-bottom-left
border = { "", "█", "", "█", "", "█", "", "█" }
border = { "", "▄", "", "█", "", "▀", "", "█" }