Update

local/share/sway/scripts/scale.sh

@@ -0,0 +1,36 @@
+#!/bin/sh
+make=$(swaymsg -t get_outputs | jq -r '.[] | select(.focused==true) | .make')
+model=$(swaymsg -t get_outputs | jq -r '.[] | select(.focused==true) | .model')
+name=$(swaymsg -t get_outputs | jq -r '.[] | select(.focused==true) | .name')
+current_screen="$make $model ($name"
+
+increment=0.25
+
+current_scale() { 
+    swaymsg -t get_outputs | jq -r '.[] | select(.focused==true) | .scale'
+}
+
+next_scale=$(current_scale)
+
+scale() {
+    [ -x "$(command -v way-displays)" ] && way-displays -s SCALE "$current_screen" $next_scale && way-displays -w || swaymsg output "\"$name\"" scale "$next_scale"
+}
+
+case $1'' in
+'')
+    current_scale
+;;
+'up')
+    next_scale=$(echo "$(current_scale) + $increment" | bc)
+    scale
+    ;;
+'down')
+    next_scale=$(echo "$(current_scale) - $increment" | bc)
+    scale
+    ;;
+'default')
+    next_scale=1
+    scale
+    ;;
+esac
+