gamerandr: Display mode switching automation for GNOME Wayland

gamerandr

#!/bin/sh

# This program uses gnome-randr (https://github.com/maxwellainatchi/gnome-randr-rust)
# to change display configurations for the duration of a process.
# It's intended to use with games if you're normally using the computer with
# DPI scaling enabled.
# Usage: gamerandr <config> [command...]
# It can be used with Steam by changing the launch options of a game to:
# gamerandr <config> %command%
# For example, I use 'gamerandr fps %command%' for Counter-Strike 2,
# and 'gamerandr cinematic %command%' for Baldur's Gate 3.

# These options select what config to return back to when the process exits.
STD_MODE=3840x2160@143.988
STD_SCALE=1.5

CONF="$1"
shift

# These are the available configs.
if [ "$CONF" = cinematic ]; then
	MODE=3840x2160@89.984
	SCALE=1
elif [ "$CONF" = fps ]; then
	MODE=3840x2160@143.988
	SCALE=1
elif [ "$CONF" = std ]; then
	MODE="$STD_MODE"
	SCALE="$STD_SCALE"
else
	echo "Unknown config: '$CONF'" >&2
	exit 1
fi

PRIMARY="$(gnome-randr query --summary \
	| grep 'primary: yes' -A2 \
	| tail -n 1 \
	| awk '{print $1}')"
if [ -z "$PRIMARY" ]; then
	echo "Failed to find primary monitor!" >&1
	exit 1
fi

reset() {
	if [ "$MODE" != "$STD_MODE" ] || [ "$SCALE" != "$STD_SCALE" ]; then
		echo ' === Reset config...' >&2
		exec gnome-randr modify --mode "$STD_MODE" --scale "$STD_SCALE" "$PRIMARY"
	fi
}

trap reset exit TERM INT

echo ' === Set config...' >&2
gnome-randr modify --mode "$MODE" --scale "$SCALE" "$PRIMARY"
"$@"