attempt to add gamescope overlay

Author: zhongjis

overlays/default.nix

@@ -16,6 +16,21 @@
     #     hash = "sha256-2Wp426uBn1V1AXNERESZW1Ax69zBW3ev672NvAKvNPQ=";
     #   };
     # });
+    gamescope = prev.gamescope.overrideAttrs (oldAttrs: rec {
+      version = "3.16.4";
+      src = prev.fetchFromGitHub {
+        owner = "ValveSoftware";
+        repo = "gamescope";
+        rev = "refs/tags/${version}";
+        fetchSubmodules = true;
+        hash = "sha256-2AxqvZA1eZaJFKMfRljCIcP0M2nMngw0FQiXsfBW7IA=";
+      };
+
+      patches = [
+        ./shaders-path.patch
+        ./gamescopereaper.patch
+      ];
+    });
   };
 
   # When applied, the unstable nixpkgs set (declared in the flake inputs) will

overlays/gamescopereaper.patch

@@ -0,0 +1,13 @@
+diff --git a/src/Utils/Process.cpp b/src/Utils/Process.cpp
+index 5688fb1..6cea8d8 100644
+--- a/src/Utils/Process.cpp
++++ b/src/Utils/Process.cpp
+@@ -392,7 +392,7 @@ namespace gamescope::Process
+     pid_t SpawnProcessInWatchdog( char **argv, bool bRespawn, std::function<void()> fnPreambleInChild )
+     {
+         std::vector<char *> args;
+-        args.push_back( (char *)"gamescopereaper" );
++        args.push_back( (char *)"@gamescopereaper@" );
+         if ( bRespawn )
+             args.push_back( (char *)"--respawn" );
+         args.push_back( (char *)"--" );

overlays/shaders-path.patch

@@ -0,0 +1,13 @@
+diff --git a/src/reshade_effect_manager.cpp b/src/reshade_effect_manager.cpp
+index 3597ca1..de45250 100644
+--- a/src/reshade_effect_manager.cpp
++++ b/src/reshade_effect_manager.cpp
+@@ -34,7 +34,7 @@ static std::string GetLocalUsrDir()
+
+ static std::string GetUsrDir()
+ {
+-    return "/usr";
++    return "@out@";
+ }
+
+ static LogScope reshade_log("gamescope_reshade");