Update flake.nix

flake.nix

@@ -1,16 +1,69 @@
 {
+  description = "VoxelCore – voxel game engine in C++";
+
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
     flake-utils.url = "github:numtide/flake-utils";
   };
 
-  outputs = { self, nixpkgs, flake-utils }:
-    flake-utils.lib.eachDefaultSystem (system: {
-        devShells.default = with nixpkgs.legacyPackages.${system}; mkShell {
-          nativeBuildInputs = [ cmake pkg-config ];
-          buildInputs = [ glm glfw glew zlib libpng libvorbis openal luajit curl ]; # libglvnd
-          packages = [ glfw mesa freeglut entt ];
-          LD_LIBRARY_PATH = "${wayland}/lib:$LD_LIBRARY_PATH";
+  outputs =
+    {
+      self,
+      nixpkgs,
+      flake-utils,
+    }:
+    flake-utils.lib.eachDefaultSystem (
+      system:
+      let
+        pkgs = import nixpkgs { inherit system; };
+        voxel-core = pkgs.stdenv.mkDerivation {
+          name = "voxel-core";
+
+          src = ./.;
+
+          nativeBuildInputs = with pkgs; [
+            cmake
+            pkg-config
+          ];
+
+          buildInputs = with pkgs; [
+            glm
+            glfw
+            glew
+            zlib
+            libpng
+            libvorbis
+            openal
+            luajit
+            curl
+            entt
+            mesa
+            freeglut
+          ]; # libglvnd
+
+          packages = with pkgs; [
+            glfw
+            mesa
+            freeglut
+            entt
+          ];
+          cmakeFlags = [
+            "-DCMAKE_PREFIX_PATH=${pkgs.entt}"
+            "-DCMAKE_INCLUDE_PATH=${pkgs.entt}/include"
+          ];
+
+          installPhase = ''
+            mkdir -p $out/bin
+            cp VoxelEngine $out/bin/
+          '';
+        };
+      in
+      {
+        packages.default = voxel-core;
+        apps.default = {
+          type = "app";
+          program = "${voxel-core}/bin/VoxelCore";
         };
-    });
+      }
+    );
 }