Replace Nix shell configuration with a Flake

flake.nix

@@ -0,0 +1,52 @@
+{
+  description = "Basic flake for Codename Engine, primarily useful for development";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs?ref=nixpkgs-unstable";
+    systems.url = "github:nix-systems/default";
+    flake-compat = {
+      url = "github:NixOS/flake-compat";
+      flake = false;
+    };
+  };
+
+  outputs =
+    { nixpkgs, systems, ... }:
+    let
+      forEachSystem = nixpkgs.lib.genAttrs (import systems);
+    in
+    {
+      devShells = forEachSystem (
+        system:
+        let
+          pkgs = nixpkgs.legacyPackages.${system};
+        in
+        {
+          default = pkgs.mkShell rec {
+            name = "cne";
+            buildInputs = with pkgs; [
+              kdePackages.qttools
+              openal
+              libpulseaudio
+              libvlc
+              libGL
+              libx11
+              libxext
+              libxinerama
+              libxi
+              libxrandr
+              SDL2
+            ];
+            nativeBuildInputs = with pkgs; [
+              haxe
+              neko
+            ];
+            shellHook = ''
+              ./building/setup-unix.sh
+            '';
+            LD_LIBRARY_PATH = pkgs.lib.makeLibraryPath buildInputs;
+          };
+        }
+      );
+    };
+}

shell.nix

@@ -1,42 +1,12 @@
-{ }:
-let
-  pkgs = import (builtins.fetchTarball {
-    url = "https://github.com/NixOS/nixpkgs/archive/c407032be28ca2236f45c49cfb2b8b3885294f7f.tar.gz";
-  }) { };
-
-  libs =
-    with pkgs;
-    [
-      SDL2
-      pkg-config
-      openal
-      alsa-lib
-      libvlc
-      libpulseaudio
-      libGL
-    ]
-    ++ (with xorg; [
-      libX11
-      libXext
-      libXinerama
-      libXi
-      libXrandr
-    ]);
-in
-pkgs.mkShell {
-  name = "CodenameEngine";
-
-  packages = with pkgs; [
-    haxe
-    neko
-    libsForQt5.qttools
-  ];
-
-  buildInputs = libs;
-
-  LD_LIBRARY_PATH = pkgs.lib.makeLibraryPath libs;
-
-  shellHook = ''
-    source update.sh
-  '';
-}
+(import (
+  let
+    lock = builtins.fromJSON (builtins.readFile ./flake.lock);
+    nodeName = lock.nodes.root.inputs.flake-compat;
+  in
+  fetchTarball {
+    url =
+      lock.nodes.${nodeName}.locked.url
+        or "https://github.com/NixOS/flake-compat/archive/${lock.nodes.${nodeName}.locked.rev}.tar.gz";
+    sha256 = lock.nodes.${nodeName}.locked.narHash;
+  }
+) { src = ./.; }).shellNix