fontscale

#       fontscale
# Font scaling program which converts a vector font to a FONT.bdf
# using `otf2bdf`
#
# This program is licensed under the ISC License.
# Copyright 2026 uint
# 
# Permission to use, copy, modify, and/or distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notice and this permission notice appear in all copies.
# 
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
# REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
# FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
# INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
# LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
# OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
# PERFORMANCE OF THIS SOFTWARE.

#!/bin/sh
set -eu

DIR="$HOME/.local/share/fonts"
FONT="$DIR/FONT.ttf"
BDF="$DIR/FONT.bdf"
META="$DIR/fontscale"
DPI=96

[ "$#" -eq 1 ] || {
	echo "Usage: fontscale {+|-}" >&2
	exit 1
}

[ -f "$FONT" ] || {
	echo "Font not found: $FONT" >&2
	exit 1
}

[ -f "$META" ] || {
	echo "Scale file not found: $META" >&2
	exit 1
}

scale=$(cat "$META")

case "$scale" in
	''|*[!0-9]*)
		echo "Invalid scale in $META: $scale" >&2
		exit 1
		;;
esac

case "$1" in
	+)
		scale=$((scale + 1))
		;;
	-)
		[ "$scale" -gt 1 ] || {
			echo "Scale cannot be less than 1" >&2
			exit 1
		}
		scale=$((scale - 1))
		;;
	*)
		echo "Usage: fontscale [+|-]" >&2
		exit 1
		;;
esac

otf2bdf -n -p "$scale" -r "$DPI" -o "$BDF" "$FONT"
printf '%s\n' "$scale" >"$META"