From a2814629a0f0a21214c532698dbd2e774012c0b4 Mon Sep 17 00:00:00 2001
From: Henrik Lissner <git@henrik.io>
Date: Fri, 23 Aug 2024 17:26:34 -0400
Subject: [PATCH] feat(bidi): add +bidi-*-font-scale vars

Close: #7687
---
 modules/input/bidi/README.org | 12 ++++++++++
 modules/input/bidi/config.el  | 41 +++++++++++++++++++++++++----------
 2 files changed, 42 insertions(+), 11 deletions(-)

diff --git a/modules/input/bidi/README.org b/modules/input/bidi/README.org
index 1cea6aeb5..572f017ea 100644
--- a/modules/input/bidi/README.org
+++ b/modules/input/bidi/README.org
@@ -39,6 +39,18 @@ It also provides easy font configuration for Hebrew and Arabic-derived scripts
 See [[Fonts]] for more information. If you use an RTL language that isn't covered by
 these characters, open an issue requesting support for it.
 
+To resize fonts, don't include a ~:size~ parameter in ~+bidi-hebrew-font~ or
+~+bidi-arabic-font~, set ~+bidi-hebrew-font-scale~ or ~+bidi-arabic-font-scale~
+instead, or add an entry to ~face-font-rescale-alist~ for your font. E.g.
+#+begin_src emacs-lisp
+;;; Add to $DOOMDIR/config.el
+(setq +bidi-arabic-font-scale 1.5)
+;; or
+(setq +bidi-hebrew-font-scale 2.5)
+;; or
+(add-to-list 'face-font-rescale-alist '("DejaVu Sans" . 1.2))
+#+end_src
+
 * Configuration
 ** Using ~+bidi-mode~
 ~+bidi-mode~ is a local minor mode, meaning it has to be turned on a per-buffer
diff --git a/modules/input/bidi/config.el b/modules/input/bidi/config.el
index 1b91819a2..8673ac5ed 100644
--- a/modules/input/bidi/config.el
+++ b/modules/input/bidi/config.el
@@ -1,14 +1,16 @@
 ;;; input/bidi/config.el -*- lexical-binding: t; -*-
 
-(defvar +bidi-mode-map (make-sparse-keymap)
-  "Keymap for `+bidi-mode'.")
-
 (defvar +bidi-hebrew-font (font-spec :family "DejaVu Sans")
   "Overriding font for hebrew script.
 Must be a `font-spec', see `doom-font' for examples.
 
 WARNING: if you specify a size for this font it will hard-lock any usage of this
-font to that size. It's rarely a good idea to do so!")
+font to that size. It's rarely a good idea to do so! Set
+`+bidi-hebrew-font-scale' to scale the font up or down.")
+
+(defcustom +bidi-hebrew-font-scale 1.0
+  "What scale to display `+bidi-hebrew-font' at."
+  :type 'float)
 
 (defface +bidi-hebrew-face `((t :font ,+bidi-hebrew-font)) "")
 
@@ -17,7 +19,12 @@ font to that size. It's rarely a good idea to do so!")
 Must be a `font-spec', see `doom-font' for examples.
 
 WARNING: if you specify a size for this font it will hard-lock any usage of this
-font to that size. It's rarely a good idea to do so!")
+font to that size. It's rarely a good idea to do so! Set
+`+bidi-arabic-font-scale' to scale the font up or down.")
+
+(defcustom +bidi-arabic-font-scale 1.0
+  "What scale to display `+bidi-arabic-font' at."
+  :type 'float)
 
 (defface +bidi-arabic-face `((t :font ,+bidi-arabic-font)) "")
 
@@ -51,7 +58,10 @@ Warning: do not change this if you are using `+bidi-global-mode'.'"
           (const :tag "Right to Left" right-to-left)
           (const :tag "Dynamic, according to paragraph text" nil)))
 
-;;;###autoload
+
+(defvar +bidi-mode-map (make-sparse-keymap)
+  "Keymap for `+bidi-mode'.")
+
 (define-minor-mode +bidi-mode
   "Minor mode for using bidirectional text in a buffer.
 
@@ -85,9 +95,18 @@ easier."
 
 (define-globalized-minor-mode +bidi-global-mode +bidi-mode +bidi-mode)
 
+
 (add-hook! 'after-setting-font-hook
-  (defun +bidi-set-fonts-h ()
-    (set-fontset-font t 'hebrew +bidi-hebrew-font)
-    (set-fontset-font t 'arabic +bidi-arabic-font)
-    (set-face-font '+bidi-arabic-face +bidi-arabic-font)
-    (set-face-font '+bidi-hebrew-face +bidi-hebrew-font)))
+  (defun +bidi-init-fonts-h ()
+    (when +bidi-hebrew-font
+      (set-fontset-font t 'hebrew +bidi-hebrew-font)
+      (set-face-font '+bidi-hebrew-face +bidi-hebrew-font)
+      (when (/= +bidi-hebrew-font-scale 1.0)
+        (setf (alist-get (font-get +bidi-hebrew-font :family) face-font-rescale-alist nil nil #'equal)
+              +bidi-hebrew-font-scale)))
+    (when +bidi-arabic-font
+      (set-fontset-font t 'arabic +bidi-arabic-font)
+      (set-face-font '+bidi-arabic-face +bidi-arabic-font)
+      (when (/= +bidi-arabic-font-scale 1.0)
+        (setf (alist-get (font-get +bidi-arabic-font :family) face-font-rescale-alist nil nil #'equal)
+              +bidi-arabic-font-scale)))))