sway: only enable vrr on fullscreen

scripts/default.nix

@@ -130,6 +130,7 @@
       coreutils
       gnugrep
     ];
+    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

user/sway/default.nix

@@ -69,7 +69,7 @@ in
           };
         output = {
           "*" = {
-            adaptive_sync = "enabled";
+            adaptive_sync = "off";
             bg = "${theme.background} fill";
             mode = "1920x1080@144.000Hz";
           };
@@ -116,6 +116,21 @@ in
       indicator = true;
     };
 
+    systemd.user.services.vrr-fullscreen = {
+      Unit = {
+        Description = "Enable VRR for fullscreen windows";
+        PartOf = [ "graphical-session.target" ];
+        After = [ "graphical-session.target" ];
+      };
+      Service = {
+        ExecStart = "${lib.getExe pkgs.vrr-fullscreen}";
+        Restart = "on-failure";
+      };
+      Install = {
+        WantedBy = [ "sway-session.target" ];
+      };
+    };
+
     xdg.configFile."OpenTabletDriver/settings.json".source = ./open-tablet-driver.json;
 
     home.packages = with pkgs; [