sway: only enable vrr on fullscreen

scripts/default.nix

@@ -126,6 +126,7 @@
       wl-clipboard
     ];
     auto_connect_gamepad = [ bluez ];
+    vrr-fullscreen = [ ];
   }
   // lib.mapAttrs import_script {
     wdmenu = ./wdmenu.nix;

scripts/vrr-fullscreen

@@ -0,0 +1,28 @@
+#!/usr/bin/env bash
+
+# List of supported outputs for VRR
+output_vrr_whitelist=(
+    "DP-1"
+    "DP-2"
+)
+
+# Toggle VRR for fullscreened apps in prespecified displays to avoid stutters while in desktop
+swaymsg -t subscribe -m '[ "window" ]' | while read window_json; do
+    window_event=$(echo ${window_json} | jq -r '.change')
+
+    # Process only focus change and fullscreen toggle
+    if [[ $window_event = "focus" || $window_event = "fullscreen_mode" ]]; then
+        output_json=$(swaymsg -t get_outputs | jq -r '.[] | select(.focused == true)')
+        output_name=$(echo ${output_json} | jq -r '.name')
+
+        # Use only VRR in whitelisted outputs
+        if [[ ${output_vrr_whitelist[*]} =~ ${output_name} ]]; then
+            output_vrr_status=$(echo ${output_json} | jq -r '.adaptive_sync_status')
+            window_fullscreen_status=$(echo ${window_json} | jq -r '.container.fullscreen_mode')
+
+            # Only update output if nesseccary to avoid flickering
+            [[ $output_vrr_status = "disabled" && $window_fullscreen_status = "1" ]] && swaymsg output "${output_name}" adaptive_sync 1
+            [[ $output_vrr_status = "enabled" && $window_fullscreen_status = "0" ]] && swaymsg output "${output_name}" adaptive_sync 0
+        fi
+    fi
+done