progress in multi user config

modules/home/desktop/applications/steam.nix

@@ -0,0 +1,57 @@
+{ options, config, lib, pkgs, user, ... }:
+let
+  inherit (lib.modules) mkIf mkForce mkMerge;
+
+  cfg = config.modules.${user}.desktop.applications.steam;
+  desktop = config.modules.${user}.desktop;
+in
+{
+  options.modules.${user}.desktop.applications.steam = let
+    inherit (lib.options) mkEnableOption;
+  in {
+    enable = mkEnableOption "Enable steam, the game/software store";
+    hardware.enable = mkEnableOption "Support for steam hardware";
+  };
+
+  config = mkIf cfg.enable (mkMerge [
+    {
+      programs.steam = {
+        enable = true;
+        package = pkgs.steam-small.override {
+          extraEnv = {
+            DXVK_HUD = "compiler";
+            MANGOHUD = true;
+          };
+        };
+      };
+      hardware.steam-hardware.enable = mkForce cfg.hardware.enable;
+
+      # https://github.com/FeralInteractive/gamemode
+      programs.gamemode = {
+        enable = true;
+        enableRenice = true;
+        settings = {};
+      };
+    }
+
+    (mkIf (desktop.type == "wayland") {
+      # https://github.com/ValveSoftware/gamescope
+      programs.gamescope = {
+        enable = true;
+        capSysNice = true;
+        env = {
+          DXVK_HDR = "1";
+          ENABLE_GAMESCOPE_WSI = "1";
+          WINE_FULLSCREEN_FSR = "1";
+          WLR_RENDERER = "vulkan";
+        };
+        args = ["--hdr-enabled"];
+      };
+
+      programs.steam.gamescopeSession = {
+        enable = true;
+        args = ["--immediate-flips"];
+      };
+    })
+  ]);
+}