Add nix-shell to allow native build on NixOS (shadps4-emu#2333)

* Add nix-shell to allow native build on NixOS

* Remove unnecessary README for nix. Move major comment to shell.nix

* Update path in building-linux.md

* Use cached nix packages from unstable channel

* Add proper license to nix shell

documents/building-linux.md

@@ -37,6 +37,12 @@ sudo pacman -S base-devel clang git cmake sndio jack2 openal qt6-base qt6-declar
 sudo zypper install clang git cmake libasound2 libpulse-devel libsndio7 libjack-devel openal-soft-devel libopenssl-devel zlib-devel libedit-devel systemd-devel libevdev-devel qt6-base-devel qt6-multimedia-devel qt6-svg-devel qt6-linguist-devel qt6-gui-private-devel vulkan-devel vulkan-validationlayers
 ```
 
+#### NixOS
+
+```
+nix-shell shell.nix
+```
+
 #### Other Linux distributions
 
 You can try one of two methods:
@@ -49,7 +55,7 @@ distrobox create --name archlinux --init --image archlinux:latest
 ```
 
 and install the dependencies on that container as cited above.
-This option is **highly recommended** for NixOS and distributions with immutable/atomic filesystems (example: Fedora Kinoite, SteamOS).
+This option is **highly recommended** for distributions with immutable/atomic filesystems (example: Fedora Kinoite, SteamOS).
 
 ### Cloning
 

shell.nix

@@ -0,0 +1,70 @@
+# SPDX-FileCopyrightText: 2024 shadPS4 Emulator Project
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+with import (fetchTarball "https://github.com/nixos/nixpkgs/archive/cfd19cdc54680956dc1816ac577abba6b58b901c.tar.gz") { };
+
+pkgs.mkShell {
+  name = "shadps4-build-env";
+
+  nativeBuildInputs = [
+    pkgs.llvmPackages_18.clang
+    pkgs.cmake
+    pkgs.pkg-config
+    pkgs.git
+  ];
+
+  buildInputs = [
+    pkgs.alsa-lib
+    pkgs.libpulseaudio
+    pkgs.openal
+    pkgs.openssl
+    pkgs.zlib
+    pkgs.libedit
+    pkgs.udev
+    pkgs.libevdev
+    pkgs.SDL2
+    pkgs.jack2
+    pkgs.sndio
+    pkgs.qt6.qtbase
+    pkgs.qt6.qttools
+    pkgs.qt6.qtmultimedia
+
+    pkgs.vulkan-headers
+    pkgs.vulkan-utility-libraries
+    pkgs.vulkan-tools
+
+    pkgs.ffmpeg
+    pkgs.fmt
+    pkgs.glslang
+    pkgs.libxkbcommon
+    pkgs.wayland
+    pkgs.xorg.libxcb
+    pkgs.xorg.xcbutil
+    pkgs.xorg.xcbutilkeysyms
+    pkgs.xorg.xcbutilwm
+    pkgs.sdl3
+    pkgs.stb
+    pkgs.qt6.qtwayland
+    pkgs.wayland-protocols
+  ];
+
+  shellHook = ''
+    echo "Entering shadPS4 dev shell"
+    export QT_QPA_PLATFORM="wayland"
+    export QT_PLUGIN_PATH="${pkgs.qt6.qtwayland}/lib/qt-6/plugins:${pkgs.qt6.qtbase}/lib/qt-6/plugins"
+    export QML2_IMPORT_PATH="${pkgs.qt6.qtbase}/lib/qt-6/qml"
+    export CMAKE_PREFIX_PATH="${pkgs.vulkan-headers}:$CMAKE_PREFIX_PATH"
+
+    # OpenGL
+    export LD_LIBRARY_PATH="${
+      pkgs.lib.makeLibraryPath [
+        pkgs.libglvnd
+        pkgs.vulkan-tools
+      ]
+    }:$LD_LIBRARY_PATH"
+
+    export LDFLAGS="-L${pkgs.llvmPackages_18.libcxx}/lib -lc++"
+    export LC_ALL="C.UTF-8"
+    export XAUTHORITY=${builtins.getEnv "XAUTHORITY"}
+  '';
+}