From b5d2d701d1e983fe82770905e8fce703ba38caa3 Mon Sep 17 00:00:00 2001
From: Sefa Eyeoglu <contact@scrumplex.net>
Date: Mon, 20 Mar 2023 18:39:50 +0100
Subject: [PATCH] nixos/fontconfig: refactor antialias option for fontconfig
 2.14.1

`sub-pixel` has been enabled by default since 2.14.1: https://gitlab.freedesktop.org/fontconfig/fontconfig/-/commit/2b6afa02ab2b7dd3796a48cf47896c4c6de4d6ba
`antialias` since 2.14.1: https://gitlab.freedesktop.org/fontconfig/fontconfig/-/commit/0825a178e82c58ae97e908d49e5ad7abe88ed7f5
`lcdfilter` since 2.13.95: https://gitlab.freedesktop.org/fontconfig/fontconfig/-/commit/e1c7c6d7442ace9c20c424265880ff57c23881f8
`hintstyle` since 2.12.1: https://gitlab.freedesktop.org/fontconfig/fontconfig/-/commit/98434b3392172233094cac25ade7225c93da9f1c

Signed-off-by: Sefa Eyeoglu <contact@scrumplex.net>
---
 nixos/modules/config/fonts/fontconfig.nix | 59 ++++++++++++++++-------
 1 file changed, 41 insertions(+), 18 deletions(-)

diff --git a/nixos/modules/config/fonts/fontconfig.nix b/nixos/modules/config/fonts/fontconfig.nix
index 5781679241ef..a49595c58e1c 100644
--- a/nixos/modules/config/fonts/fontconfig.nix
+++ b/nixos/modules/config/fonts/fontconfig.nix
@@ -77,18 +77,6 @@ let
         <edit mode="append" name="autohint">
           ${fcBool cfg.hinting.autohint}
         </edit>
-        <edit mode="append" name="hintstyle">
-          <const>${cfg.hinting.style}</const>
-        </edit>
-        <edit mode="append" name="antialias">
-          ${fcBool cfg.antialias}
-        </edit>
-        <edit mode="append" name="rgba">
-          <const>${cfg.subpixel.rgba}</const>
-        </edit>
-        <edit mode="append" name="lcdfilter">
-          <const>lcd${cfg.subpixel.lcdfilter}</const>
-        </edit>
       </match>
 
     </fontconfig>
@@ -177,6 +165,13 @@ let
     </fontconfig>
   '';
 
+  # Replace default linked config with a different variant
+  replaceDefaultConfig = defaultConfig: newConfig: ''
+    rm $dst/${defaultConfig}
+    ln -s ${pkg.out}/share/fontconfig/conf.avail/${newConfig} \
+          dst/
+  '';
+
   # fontconfig configuration package
   confPkg = pkgs.runCommand "fontconfig-conf" {
     preferLocalBuild = true;
@@ -196,6 +191,26 @@ let
     ln -s ${pkg.out}/etc/fonts/conf.d/*.conf \
           $dst/
 
+    ${optionalString (!cfg.antialias)
+      (replaceDefaultConfig "10-yes-antialias.conf"
+        "10-no-antialias.conf")
+    }
+
+    ${optionalString (cfg.hinting.style != "slight")
+      (replaceDefaultConfig "10-hinting-slight.conf"
+        "10-hinting-${cfg.hinting.style}.conf")
+    }
+
+    ${optionalString (cfg.subpixel.rgba != "none")
+      (replaceDefaultConfig "10-sub-pixel-none.conf"
+        "10-sub-pixel-${cfg.subpixel.rgba}.conf")
+    }
+
+    ${optionalString (cfg.subpixel.lcdfilter != "default")
+      (replaceDefaultConfig "11-lcdfilter-default.conf"
+        "11-lcdfilter-${cfg.subpixel.lcdfilter}.conf")
+    }
+
     # 00-nixos-cache.conf
     ln -s ${cacheConf}  $dst/00-nixos-cache.conf
 
@@ -367,17 +382,25 @@ in
           };
 
           style = mkOption {
-            type = types.enum [ "hintnone" "hintslight" "hintmedium" "hintfull" ];
-            default = "hintslight";
+            type = types.enum ["none" "slight" "medium" "full"];
+            default = "slight";
             description = lib.mdDoc ''
               Hintstyle is the amount of font reshaping done to line up
               to the grid.
 
-              hintslight will make the font more fuzzy to line up to the grid
-              but will be better in retaining font shape, while hintfull will
-              be a crisp font that aligns well to the pixel grid but will lose
-              a greater amount of font shape.
+              slight will make the font more fuzzy to line up to the grid but
+              will be better in retaining font shape, while full will be a
+              crisp font that aligns well to the pixel grid but will lose a
+              greater amount of font shape.
             '';
+            apply =
+              val:
+              let
+                from = "fonts.fontconfig.hinting.style";
+                val' = lib.removePrefix "hint" val;
+                warning = "The option `${from}` contains a deprecated value `${val}`. Use `${val'}` instead.";
+              in
+              lib.warnIf (lib.hasPrefix "hint" val) warning val';
           };
         };