Created flake and added license.txt

flake.nix

@@ -0,0 +1,187 @@
+{
+  description = "Regolith, a retained mode GUI library for Odin";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+
+    # Pinned to the latest monthly release tag
+    # If you change this, also change odinVersion below
+    odin-src = {
+      url = "github:odin-lang/Odin/dev-2026-10";
+      flake = false;
+    };
+
+    # OLS must match the Odin revision
+    ols-src = {
+      url = "github:DanielGavin/ols/dev-2026-10";
+      flake = false;
+    };
+  };
+
+  outputs = { self, nixpkgs, odin-src, ols-src }:
+    let
+      lib = nixpkgs.lib;
+      systems = [ "x86_64-linux" "aarch64-linux" ];
+      forAllSystems = f:
+        lib.genAttrs systems (system: f nixpkgs.legacyPackages.${system});
+
+      odinVersion = "2026-10";
+
+      build = pkgs:
+        let
+          llvmPackages = pkgs.llvmPackages_20;
+
+          odin = llvmPackages.stdenv.mkDerivation {
+            pname = "odin";
+            version = "dev-${odinVersion}";
+            src = odin-src;
+
+            nativeBuildInputs = [ pkgs.makeBinaryWrapper pkgs.which ];
+            buildInputs = [ llvmPackages.llvm ];
+
+            LLVM_CONFIG = "${llvmPackages.llvm.dev}/bin/llvm-config";
+
+            # The build script stamps the version from the build date, which is
+            # meaningless inside the Nix sandbox. Stamp the tag instead.
+            postPatch = ''
+              substituteInPlace build_odin.sh \
+                --replace-fail '$(date +"%Y-%m")' '${odinVersion}'
+              patchShebangs build_odin.sh
+            '';
+
+            dontConfigure = true;
+
+            buildPhase = ''
+              runHook preBuild
+              ./build_odin.sh release
+              runHook postBuild
+            '';
+
+            installPhase = ''
+              runHook preInstall
+
+              mkdir -p $out/bin $out/share
+              cp odin $out/bin/odin
+              for d in base core vendor shared; do
+                if [ -d "$d" ]; then cp -r "$d" $out/share/; fi
+              done
+
+              wrapProgram $out/bin/odin \
+                --prefix PATH : ${lib.makeBinPath [
+                  llvmPackages.bintools
+                  llvmPackages.clang
+                  llvmPackages.lld
+                ]} \
+                --set-default ODIN_ROOT $out/share
+
+              # Build the C parts of the vendor collection.
+              for v in stb cgltf miniaudio; do
+                d="$out/share/vendor/$v/src"
+                [ -d "$d" ] || continue
+                if [ -f "$d/Makefile" ] || [ -f "$d/makefile" ] || [ -f "$d/GNUmakefile" ]; then
+                  make -C "$d"
+                elif [ -f "$d/build_$v.sh" ]; then
+                  patchShebangs "$d/build_$v.sh"
+                  (cd "$d" && "./build_$v.sh") || echo "vendor/$v: build script failed, skipping"
+                else
+                  echo "vendor/$v/src: no known build entry point, skipping"
+                fi
+              done
+
+              runHook postInstall
+            '';
+          };
+
+          ols = pkgs.stdenv.mkDerivation {
+            pname = "ols";
+            version = "dev-${odinVersion}";
+            src = ols-src;
+
+            nativeBuildInputs = [ odin ];
+            dontConfigure = true;
+
+            postPatch = ''
+              patchShebangs build.sh odinfmt.sh
+            '';
+
+            buildPhase = ''
+              runHook preBuild
+              ./build.sh
+              ./odinfmt.sh
+              runHook postBuild
+            '';
+
+            installPhase = ''
+              runHook preInstall
+              install -Dm755 ols $out/bin/ols
+              install -Dm755 odinfmt $out/bin/odinfmt
+              runHook postInstall
+            '';
+          };
+        in
+        { inherit odin ols llvmPackages; };
+    in
+    {
+      packages = forAllSystems (pkgs:
+        let p = build pkgs; in {
+          inherit (p) odin ols;
+          default = p.odin;
+        });
+
+      devShells = forAllSystems (pkgs:
+        let
+          p = build pkgs;
+          llvmPackages = p.llvmPackages;
+
+          runtimeLibs = with pkgs; [
+            sdl3
+            wayland
+            libxkbcommon
+            libdecor
+            vulkan-loader
+            libGL
+          ];
+        in
+        {
+          default = (pkgs.mkShell.override { stdenv = llvmPackages.stdenv; }) {
+            name = "regolith";
+
+            packages = [
+              # Odin toolchain
+              p.odin
+              p.ols
+              llvmPackages.lld
+              llvmPackages.bintools
+
+              # Native build and runtime
+              pkgs.pkg-config
+              pkgs.sdl3
+
+              # WASM
+              pkgs.emscripten
+              pkgs.nodejs
+              pkgs.python3
+
+              # Lua tooling (the engine builds its own vendored Lua)
+              pkgs.lua5_4
+              pkgs.lua54Packages.luacheck
+
+              # Debugging
+              pkgs.gdb
+              pkgs.valgrind
+              pkgs.git
+            ];
+
+            shellHook = ''
+              # Emscripten needs a writable cache, and the store is read only.
+              export EM_CACHE="$PWD/.cache/emscripten"
+              mkdir -p "$EM_CACHE"
+
+              # SDL3 dlopens these at runtime. nixpkgs SDL3 is patched to find
+              # most of them, this is a fallback for anything built outside Nix.
+              export LD_LIBRARY_PATH="${lib.makeLibraryPath runtimeLibs}:/run/opengl-driver/lib:''${LD_LIBRARY_PATH:-}"
+            '';
+          };
+        });
+    };
+}