In my recent project, I needed to draw lines at angles and also rotate 48×48 pixels bitmap before showing on display. Since I didn't find any samples, thought I post these specific pieces of code on my blog and Gist for others to use.
Blog post: https://chall3ng3r.com/blog/2020/04/drawing-rotated-lines-bitmaps-with-arduino/
Gist: https://gist.github.com/chall3ng3r/1c8f1d43d948d9371671edf9967c68e6
Touch here for the full post on the Arduino Apprentices tumblr