@falktx
hmm yeah that file is a lot bigger than I remember of, idk why exactly, maybe a side effect of libdecor trying to be really flexible wrt how the app manages the window?

> is finding the default titlebar height and the left-shadow-position offset

for the first thing, the easiest reference I know of would be Electron's CSD, which in turn was based on Chromium's but is a fair bit shorter https://github.com/electron/electron/blob/624d0856324c20699ae0f3a60a2a34d1cc2bc8a1/shell/browser/ui/views/client_frame_view_linux.cc esp GetTitlebarBounds. not entirely sure about left-shadow-position.