Migrate to snowfall lib

modules/home/gui/theme/wallpaper-gen.nix

@@ -0,0 +1,40 @@
+{ pkgs, config }:
+
+let
+  scheme = config.colorScheme;
+  colors = scheme.colors;
+  dither =
+    "atkinson"; # none | floyd-steinberg | atkinson | jjn | burkes | sierra | sierra-lite
+in pkgs.stdenv.mkDerivation rec {
+  pname = "generated-wallpaper";
+  version = "a1676fc2a0e3dfb7bf95d8a89e592830";
+  src = pkgs.fetchFromGitea {
+    domain = "git.helcel.net";
+    owner = "sora";
+    repo = "nixconfig-wallpaper";
+    rev = version;
+    sha256 = "sha256-ZhBjTaKzoiEq1ptMmNWWRPCjLJsvy9My/HuzRaDjX1c=";
+  };
+
+  buildInputs = with pkgs; [ custom.repalette nodejs imagemagick gifsicle ];
+
+  configurePhase = ''
+    echo "${colors.base00},${colors.base01},\
+          ${colors.base02},${colors.base03},\
+          ${colors.base04},${colors.base05},\
+          ${colors.base06},${colors.base07},\
+          ${colors.base08},${colors.base09},\
+          ${colors.base0A},${colors.base0B},\
+          ${colors.base0C},${colors.base0D},\
+          ${colors.base0E},${colors.base0F}" > palette.in
+  '';
+
+  buildPhase = ''
+    make DITHER=${dither} PALETTE_SIZE=0 all
+  '';
+
+  installPhase = ''
+    mkdir -p $out/share/wallpaper
+    cp -r build/* $out/share/wallpaper/
+  '';
+}