add flake support

README.md

@@ -1,7 +1,12 @@
 # NixOS Godot Binaries
+
 > Official Godot binary packages for NixOS
+(including godot-mono for C# support!)
 
 ## Getting Started
+
+### Without Flakes ❄❌
+
 The simplest way to use these packages are to use the overlay. In your `configuration.nix`:
 
     let  
@@ -18,3 +23,73 @@ The simplest way to use these packages are to use the overlay. In your `configur
       godotMonoBin
       godotHeadlessBin
     ]
+
+### With Flakes ❄✅
+
+#### Running Godot without installing it
+
+To run Godot without any further configuration, run this command:
+
+```
+nix run github:Quoteme/nixos-godot-bin
+```
+
+##### Running different Godot flavors
+
+There are also these other options available to run Godot:
+
+```
+nix run github:Quoteme/nixos-godot-bin\#godot
+nix run github:Quoteme/nixos-godot-bin\#godotHeadless
+nix run github:Quoteme/nixos-godot-bin\#godotMono
+```
+
+Most importantly, using `\#godotMono` will allow you to write in C#.
+
+#### Installing Godot using flakes system-wide
+
+Put this in your `flake.nix`, to install Godot for your user:
+
+```
+  inputs = {
+    # ...
+    godot.url = "github:Quoteme/nixos-godot-bin";
+    # ...
+  };
+
+  outputs = { self, nixpkgs, ... }@attrs:
+    nixosConfigurations.nixos = nixpkgs.lib.nixosSystem {
+      modules = [
+        ({ config, nixpkgs, ...}@inputs:
+          users.users.YOURUSERNAME.packages = [
+            # ...
+            inputs.godot.packages.x86_64-linux.godot # for godot without Mono / C#
+            inputs.godot.packages.x86_64-linux.godotHeadless # for godot headless
+            inputs.godot.packages.x86_64-linux.godotMono
+          ]
+        )
+      ]
+```
+
+Alternatively you can also install Godot system-wide like this:
+
+```
+  inputs = {
+    # ...
+    godot.url = "github:Quoteme/nixos-godot-bin";
+    # ...
+  };
+
+  outputs = { self, nixpkgs, ... }@attrs:
+    nixosConfigurations.nixos = nixpkgs.lib.nixosSystem {
+      modules = [
+        ({ config, nixpkgs, ...}@inputs:
+          environment.systemPackages = [
+            # ...
+            inputs.godot.packages.x86_64-linux.godot # for godot without Mono / C#
+            inputs.godot.packages.x86_64-linux.godotHeadless # for godot headless
+            inputs.godot.packages.x86_64-linux.godotMono
+          ]
+        )
+      ]
+```

flake.nix

@@ -0,0 +1,85 @@
+{
+  description = "Official Godot binary packages for NixOS - An overlay for Godot";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
+    flake-utils = {
+      inputs.nixpkgs.follows = "nixpkgs";
+      url = "github:numtide/flake-utils";
+    };
+
+    # Add files needed to create a launcher icon for Godot
+    godot-desktop-file = {
+      url = "https://raw.githubusercontent.com/godotengine/godot/master/misc/dist/linux/org.godotengine.Godot.desktop";
+      flake = false;
+    };
+    godot-icon-png = {
+      url = "https://raw.githubusercontent.com/godotengine/godot/master/icon.png";
+      flake = false;
+    };
+    godot-icon-svg = {
+      url = "https://raw.githubusercontent.com/godotengine/godot/master/icon.svg";
+      flake = false;
+    };
+    godot-manpage = {
+      url = "https://raw.githubusercontent.com/godotengine/godot/master/misc/dist/linux/godot.6";
+      flake = false;
+    };
+  };
+
+  outputs = { self, nixpkgs, flake-utils, ... }@inputs:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = import nixpkgs { inherit system; };
+      in
+        rec {
+          # This section is here, so users can run:
+          # > nix run github:Quoteme/nixos-godot-bin
+          # and start Godot without any further configuration.
+          #
+          # > nix run github:Quoteme/nixos-godot-bin\#godot
+          # > nix run github:Quoteme/nixos-godot-bin\#godotHeadless
+          # > nix run github:Quoteme/nixos-godot-bin\#godotMono
+          # are also available.
+          defaultApp = apps.godot;
+          apps.godot = {
+            type = "app";
+            program = "${packages.godot}/bin/godot";
+          };
+          apps.godotHeadless = {
+            type = "app";
+            program = "${packages.godot}/bin/godot-headless";
+          };
+          apps.godotMono = {
+            type = "app";
+            program = "${packages.godotMono}/bin/godot-mono";
+          };
+
+          # This is for installing Godot using flakes
+          # just add this flake to your flakes inputs, and then you can
+          # use these packages to include Godot in your environment.
+          defaultPackage = packages.godot;
+          packages.godot = pkgs.callPackage ./pkgs/godot {
+            godotDesktopFile = inputs.godot-desktop-file;
+            godotIconPNG = inputs.godot-icon-png;
+            godotIconSVG = inputs.godot-icon-svg;
+            godotManpage = inputs.godot-manpage;
+          };
+          packages.godotHeadless = pkgs.callPackage ./pkgs/godot/headless.nix {
+            godotBin = packages.godot;
+          };
+          packages.godotMono = pkgs.callPackage ./pkgs/godot/mono.nix {
+            godotBin = packages.godot;
+            godotDesktopFile = inputs.godot-desktop-file;
+            godotIconPNG = inputs.godot-icon-png;
+            godotIconSVG = inputs.godot-icon-svg;
+            godotManpage = inputs.godot-manpage;
+          };
+          overlays.default = final: prev: {
+            godot = packages.godot;
+            godotHeadless = packages.godotHeadless;
+            godotMono = packages.godotMono;
+          };
+        }
+      );
+}

pkgs/godot/default.nix

@@ -7,6 +7,10 @@
   udev,
   alsaLib, libXcursor, libXinerama, libXrandr, libXrender, libX11, libXi,
   libpulseaudio, libGL,
+  godotDesktopFile,
+  godotIconPNG,
+  godotIconSVG,
+  godotManpage
 }:
 
 let
@@ -43,6 +47,20 @@ stdenv.mkDerivation rec {
   installPhase = ''
     mkdir -p $out/bin
     install -m 0755 Godot_v${version}-${qualifier}_x11.64 $out/bin/godot
+
+    # Only create a desktop file, if the necessary variables are set
+    # these are set only, if one installs this program using flakes.
+    if [[ -f "${godotDesktopFile}" ]]; then
+      mkdir -p "$out/man/share/man/man6"
+      cp ${godotManpage} "$out/man/share/man/man6/"
+
+      mkdir -p $out/share/{applications,icons/hicolor/scalable/apps}
+      cp ${godotDesktopFile} "$out/share/applications/org.godotengine.Godot.desktop"
+      cp ${godotIconSVG} "$out/share/icons/hicolor/scalable/apps/godot.svg"
+      cp ${godotIconPNG} "$out/share/icons/godot.png"
+      substituteInPlace "$out/share/applications/org.godotengine.Godot.desktop" \
+        --replace "Exec=godot" "Exec=$out/bin/godot"
+    fi
   '';
 
   postFixup = ''

pkgs/godot/mono.nix

@@ -3,7 +3,11 @@
   msbuild,
   dotnetPackages,
   mono5,
-  zlib
+  zlib,
+  godotDesktopFile,
+  godotIconPNG,
+  godotIconSVG,
+  godotManpage
 }:
 
 let
@@ -29,6 +33,20 @@ godotBin.overrideAttrs (oldAttrs: rec {
     cp -r GodotSharp $out/opt/godot-mono
 
     ln -s $out/opt/godot-mono/Godot_v${version}-${qualifier}_mono_x11.64 $out/bin/godot-mono
+
+    # Only create a desktop file, if the necessary variables are set
+    # these are set only, if one installs this program using flakes.
+    if [[ -f "${godotDesktopFile}" ]]; then
+      mkdir -p "$out/man/share/man/man6"
+      cp ${godotManpage} "$out/man/share/man/man6/"
+
+      mkdir -p $out/share/{applications,icons/hicolor/scalable/apps}
+      cp ${godotDesktopFile} "$out/share/applications/org.godotengine.Godot-Mono.desktop"
+      cp ${godotIconSVG} "$out/share/icons/hicolor/scalable/apps/godot.svg"
+      cp ${godotIconPNG} "$out/share/icons/godot.png"
+      substituteInPlace "$out/share/applications/org.godotengine.Godot-Mono.desktop" \
+        --replace "Exec=godot" "Exec=$out/bin/godot-mono"
+    fi
   '';
 
   postFixup = ''