Add support for pcsx2.

nix/steam_deck/configuration/roles/pcsx2/default.nix

@@ -0,0 +1,94 @@
+# MANUAL: mkdir -p ~/.persist/.config/PCSX2/memcards ~/.state/.config/PCSX2/cache ~/.state/.config/PCSX2/sstates ~/.state/.config/PCSX2/snaps ~/.state/.config/PCSX2/covers ~/.state/.config/PCSX2/videos
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+
+let
+  steam_pcsx2 = pkgs.writeScriptBin "steam_pcsx2" ''
+    export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:${pkgs.libglvnd}/lib"
+    exec ${pkgs.pcsx2}/bin/pcsx2-qt
+  '';
+in
+{
+  imports = [ ];
+
+  options.me = {
+    pcsx2.enable = lib.mkOption {
+      type = lib.types.bool;
+      default = false;
+      example = true;
+      description = "Whether we want to install pcsx2.";
+    };
+  };
+
+  config = lib.mkIf config.me.pcsx2.enable (
+    lib.mkMerge [
+      (lib.mkIf config.me.graphical {
+        home.packages = with pkgs; [
+          pcsx2
+          steam_pcsx2
+        ];
+
+        home.file.".config/PCSX2/inis/PCSX2.ini" = {
+          source = ./files/PCSX2.ini;
+        };
+
+        home.persistence."/home/deck/.persist" = {
+          directories = [
+            {
+              directory = ".config/PCSX2/memcards";
+              method = "symlink";
+            }
+          ];
+        };
+        home.persistence."/home/deck/.state" = {
+          directories = [
+            {
+              directory = ".config/PCSX2/cache";
+              method = "symlink";
+            }
+            {
+              directory = ".config/PCSX2/sstates";
+              method = "symlink";
+            }
+            {
+              directory = ".config/PCSX2/snaps";
+              method = "symlink";
+            }
+            {
+              directory = ".config/PCSX2/covers";
+              method = "symlink";
+            }
+            {
+              directory = ".config/PCSX2/videos";
+              method = "symlink";
+            }
+          ];
+        };
+
+        nixpkgs.overlays = [
+          (final: prev: {
+            pcsx2 = pkgs.buildEnv {
+              name = prev.pcsx2.name;
+              paths = [
+                (config.lib.nixGL.wrap prev.pcsx2)
+              ];
+              extraOutputsToInstall = [
+                "man"
+                "doc"
+                "info"
+              ];
+              # We have to use 555 instead of the normal 444 here because the .desktop file ends up inside $HOME on steam deck and desktop files must be either not in $HOME or must be executable, otherwise KDE Plasma refuses to execute them.
+              postBuild = ''
+                chmod 0555 $out/share/applications/PCSX2.desktop
+              '';
+            };
+          })
+        ];
+      })
+    ]
+  );
+}