readme: make it somewhat nicer

README.md

@@ -1,11 +1,56 @@
 # lsfg-vk-flake
-WIP! Nix flake to build the library for using Lossless Scaling's frame generation on Linux
+Nix flake for using [Lossless Scaling's frame generation on Linux](https://github.com/PancakeTAS/lsfg-vk)
 
-current state: builds and seems to be functional
+>[!IMPORTANT]
+> You need to have Lossless Scaling installed on Steam!
+> In case it is not installed on the default Steam drive, you may want to consider setting the environment variable ``LSFG_DLL_PATH=<ABSOLUTE_PATH_TO>/Lossless.dll``
 
-## manual install
-1. build the library with ``nix build``
-2. copy library and vulkan layer config to your ~/.local: ``cp -r result/* ~/.local/`` (check contents of result first!)
-3. have lossless scaling installed on Steam or manually reference the DLL file using LSFG_DLL_PATH
+## Installation
+### System-wide (NixOS module)
+This approach will install an implicit layer to ``/etc/vulkan/implicit_layer.d/``
 
-example usage command: ``LD_PRELOAD=~/.local/lib/liblsfg-vk.so LSFG_DLL_PATH=<POINT_ME_TO>/Lossless.dll ENABLE_LSFG=1 vkcube``
+Add this repository to your flake inputs, output function and module list:
+```nix
+inputs = {
+  ...
+  lsfg-vk-flake.url = "github:pabloaul/lsfg-vk-flake/main";
+  lsfg-vk-flake.inputs.nixpkgs.follows = "nixpkgs";
+}
+
+outputs = {nixpkgs, lsfg-vk-flake, ...}: {
+
+  nixosConfigurations.hostname = nixpkgs.lib.nixosSystem {
+    ...
+    modules = [
+      ...
+      lsfg-vk-flake.nixosModules.default
+    ];
+  };
+}
+```
+
+And then you should be able to enable this in your system config using:
+```nix 
+services.lsfg-vk.enable = true;
+
+# optional but recommended:
+environment.variables = { LSFG_DLL_PATH = "<ABSOLUTE_PATH_TO>/Lossless.dll"; }
+```
+
+### User install (manual)
+1. Build the library:
+  ``nix build``
+3. Create the following path in case it does not exist:
+  ``mkdir -p $HOME/.local/share/vulkan/implicit_layer.d`` 
+3. Symlink the build results to your $HOME/.local/
+  ``cp -ifrsv "$(readlink -f ./result)"/* $HOME/.local/``
+
+## Usage
+Run a Vulkan application with the environment variable ``ENABLE_LSFG=1`` set.
+
+Example: ``ENABLE_LSFG=1 vkcube`` and look for output like this in the terminal: lsfg-vk(...): ...
+
+You can also enable it per game on Steam by adding this to the launch options of a game like this: 
+  ``ENABLE_LSFG=1 %COMMAND%``
+
+There are many more options that can be set. Consult the original repository for further documentation.

default.nix

@@ -10,13 +10,13 @@
 
 in llvmPackages.stdenv.mkDerivation {
   pname = "lsfg-vk";
-  version = "unstable-2025-07-13-f998647";
+  version = "unstable-2025-07-14-83b869b";
 
   src = fetchFromGitHub {
     owner = "PancakeTAS";
     repo = "lsfg-vk";
-    rev = "f998647d74051467e39de9de2df2ff9a5996db5f";
-    hash = "sha256-X708aKFz3wqSVYsMvCKsY7kqi+2LTewnoOMrXFPVEPY=";
+    rev = "83b869b0c4d4cd4da2e760126242c6ed76bafec8";
+    hash = "sha256-LN6DkLN6pMmYRaj+TsAL3PLqINMeYOhQ2Kw16bRF/Q4=";
     fetchSubmodules = true;
   };
 

flake.nix

@@ -6,5 +6,6 @@
     pkgs = import nixpkgs { inherit system; };
   in {
     packages.${system}.default = pkgs.callPackage ./default.nix {};
+    nixosModules.default = import ./module.nix;
   };
 }

module.nix

@@ -0,0 +1,26 @@
+{ config, lib, pkgs, ... }:
+let
+  cfg = config.services.lsfg-vk;
+  lsfg-vk = pkgs.callPackage ./default.nix {};
+in
+{
+  options = {
+    services.lsfg-vk = {
+      enable = lib.mkEnableOption "Lossless Scaling Frame Generation Vulkan layer";
+      
+      package = lib.mkOption {
+        type = lib.types.package;
+        description = "The lsfg-vk package to use";
+        default = lsfg-vk;
+      };
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    environment.systemPackages = [ cfg.package ];
+
+    # Installs the Vulkan implicit layer system-wide
+    environment.etc."vulkan/implicit_layer.d/VkLayer_LS_frame_generation.json".source = 
+      "${cfg.package}/share/vulkan/implicit_layer.d/VkLayer_LS_frame_generation.json";
+  };
+}