add basic nix flake

flake.lock

@@ -0,0 +1,26 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1713254108,
+        "narHash": "sha256-0TZIsfDbHG5zibtlw6x0yOp3jkInIGaJ35B7Y4G8Pec=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "2fd19c8be2551a61c1ddc3d9f86d748f4db94f00",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "ref": "nixpkgs-unstable",
+        "type": "indirect"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,71 @@
+{
+  description = "PBSA: Physikalisch Basierte Simulation und Animation";
+
+  inputs.nixpkgs.url = "nixpkgs/nixpkgs-unstable";
+
+  outputs =
+    { nixpkgs
+    , self
+    , ...
+    }:
+    let
+      systems = [
+        "x86_64-linux"
+        "aarch64-linux"
+      ];
+
+      forAllSystems = f: nixpkgs.lib.genAttrs systems (system: f system);
+    in
+    {
+      devShells = forAllSystems
+        (system:
+          let
+            pkgs = nixpkgs.legacyPackages.${system};
+          in
+          {
+            default =
+              let
+                py-pkg = pkgs.python3.withPackages (python-pkgs: with python-pkgs;
+                  [
+                    # glad2 # todo
+                    glad
+                    anyqt
+                    eigenpy
+                    pip
+                  ]);
+
+              in
+              pkgs.mkShell {
+                packages = with pkgs; [
+                  # base toolchain
+                  gcc13
+                  gdb
+                  clang
+                  libgcc
+                  qt6.full
+                  qtcreator
+                  cmake
+                  nlohmann_json
+                  qt6.qtwayland
+                  icu
+                  libcxx
+                  nil
+                  libGL
+                  libGLU
+                  eigen
+                  py-pkg
+                ];
+
+                shellHook = ''
+                  # Tells pip to put packages into $PIP_PREFIX instead of the usual locations.
+                  # See https://pip.pypa.io/en/stable/user_guide/#environment-variables.
+                  export PIP_PREFIX=$(pwd)/_build/pip_packages
+                  export PYTHONPATH="$PIP_PREFIX/${py-pkg.sitePackages}:$PYTHONPATH"
+                  export PATH="$PIP_PREFIX/bin:$PATH"
+                  unset SOURCE_DATE_EPOCH
+                '';
+              };
+
+          });
+    };
+}