Enable BASE on NixOS platform

.envrc

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+use nix

shell.nix

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+{ pkgs ? import <nixpkgs> {} }:
+
+# Because of high dependency on native libraries like OpenGL and OpenAL
+# on the NixOS the BASE engine requires few modifications.
+# Basically this shell.nix could be enough, however the OpenGL is highly tied with the hardware,
+# so the following change needs to be applied in the configuration.nix (or your flake configuration, whatever):
+#  hardware.opengl = {
+#    enable = true;
+#    extraPackages = with pkgs; [
+#      libGL
+#    ];
+#    setLdLibraryPath = true;
+#  };
+#
+# Also for GNOME environments, the Editor requires the libglassgtk3.so library,
+# so it is available via xorg.libXtst package mentioned already in the shell definition below.
+
+let
+  opengl = "/run/opengl-driver";
+in pkgs.mkShell {
+  name = "BASE NixOS runtime";
+
+  buildInputs = [
+    pkgs.xorg.libXtst  # Required by editor on GNOME environments (due to libglassgtk3.so dependency)
+    pkgs.alsa-lib      # Either alsa or jack or pulseaudio library is required by game engine via OpenAL native library
+  ];
+
+  # OpenGL needs to be configured via /etc/nixos/configuration.nix
+  LD_LIBRARY_PATH = "${opengl}/lib:${pkgs.xorg.libXtst}/lib:${pkgs.alsa-lib}/lib";
+
+  shellHook = ''
+    echo
+    echo
+    echo "======================================================================================================"
+    echo "Welcome to BASE NixOS shell environment"
+    echo "Remember to provide following LD environment variable in order to run application outside this shell:"
+    echo
+    echo "LD_LIBRARY_PATH=$LD_LIBRARY_PATH"
+    echo "======================================================================================================"
+    echo
+    echo
+  '';
+}