From 23637cabc722a973d0c27555cc36276ad51bdd49 Mon Sep 17 00:00:00 2001
From: johnnyshields <27655+johnnyshields@users.noreply.github.com>
Date: Sat, 28 Feb 2026 16:56:43 +0900
Subject: [PATCH] Select correct Noto Sans CJK font variant in stargraphic
 writer

Use the profile's cjk_encoding to select the language-appropriate
Noto Sans variant (JP, SC, TC, KR) for Pango text rasterization.
This ensures correct glyph rendering for Han-unified codepoints
where the same Unicode character has different visual forms per locale.

Replaces the old fc-list-based font detection singleton with a
locale-driven lookup from the existing CJK encoding configuration.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 lib/thermal/stargraphic/writer.rb | 33 +++++++++----------------------
 1 file changed, 9 insertions(+), 24 deletions(-)

diff --git a/lib/thermal/stargraphic/writer.rb b/lib/thermal/stargraphic/writer.rb
index ea0023b..73c3316 100644
--- a/lib/thermal/stargraphic/writer.rb
+++ b/lib/thermal/stargraphic/writer.rb
@@ -190,35 +190,20 @@ def seq_exec_em
       append_raw [27, 12, 25]
     end
 
+    CJK_FONTS = {
+      'shift_jis' => 'Noto Sans JP',
+      'gb18030'   => 'Noto Sans SC',
+      'big5'      => 'Noto Sans TC',
+      'ksc5601'   => 'Noto Sans KR'
+    }.freeze
+
     def font
-      self.class.font
-    end
-
-    class << self
-      # Persists font as singleton
-      def font
-        @font ||= if OS.windows?
-                    'Sans'
-                  else
-                    font_list = begin
-                      `fc-list`
-                    rescue StandardError
-                      ''
-                    end
-                    case font_list
-                    when /NotoSans/ then 'NotoSans'
-                    else 'Sans'
-                    end
-                  end
-      end
+      CJK_FONTS[@profile.cjk_encoding&.key] || 'Noto Sans'
     end
 
-    def text_image(markup, width: @width, align: :left, font: 'Sans', delete: true)
+    def text_image(markup, width: @width, align: :left, font: self.font, delete: true)
       tmp_path = ::Thermal.tmp_path("#{SecureRandom.uuid}.png")
 
-      # TODO: Fix font loading
-      # font ||= self.class.font
-
       begin
         configure = proc do |i|
           i << '+antialias'