spin your monitor around, slowly but surely

spinny.sh

#!/bin/bash

# make sure we're not on Wayland, because xrandr doesn't work on Wayland
if [ "$(loginctl show-session $(loginctl user-status $USER | grep -E -m 1 'session-[0-9]+\.scope' | sed -E 's/^.*?session-([0-9]+)\.scope.*$/\1/') -p Type | grep -ic "wayland")" -ge 1 ]; then # stolen from stackoverflow
	echo "You aren't using X!"
	exit
fi

# no more annoying cursor
tput civis 
# return back to normal when killed because you got bored
trap cleanup 1 2 3 6

cleanup() {
	printf '\n%s\n' 'Putting display back to normal...'
	sleep 1 # allow you to read the text it prints
	xrandr --output "$o" --transform none # un-magic
	tput cnorm # give cursor back
	exit
}

# get primary display output name
o=$(xrandr | awk '/ primary / {print $1}')

# convert degrees to radians
dr () {
	echo "$1 * 0.01745329" | bc -l
}

# do the funny
i=1
j=0
while true; do
	xrandr --output "$o" --transform $(echo "c($(dr $i))" | bc -l),$(echo "-s($(dr $i))" | bc -l),0,$(echo "s($(dr $i))" | bc -l),$(echo "c($(dr $i))" | bc -l),0,0,0,1 # magic
	printf '\033[2K%s\033[1m%s\033[m\n' "CURRENT ANGLE: " "$i°"
	printf '\033[2K%s\033[1m%s\033[m\r\033[1A' "ROTATIONS SUFFERED: " "$j"
	i=$((i+1))
	if [ $i == 360 ]; then
		j=$((j+1))
	fi
	i=$((i%360)) # don't fuck off to infinity
	sleep 5 # give your screen some time to rest
done