From c1c0f11821e36e96add5060916d83533308b4126 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Ekl=C3=B6f?= <daniel@ekloef.se>
Date: Mon, 22 Nov 2021 23:02:25 +0100
Subject: [PATCH] config: add tweak.grapheme-width-method=max
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Content-Type: text/plain; charset=UTF-8
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‘max’ is a new value for ‘tweak.grapheme-width-method’. When enabled,
the width of a grapheme cluster is that of the cluster’s widest
codepoint.
---
 CHANGELOG.md       | 5 +++++
 config.c           | 2 +-
 config.h           | 6 +++++-
 doc/foot.ini.5.scd | 4 +++-
 vt.c               | 4 ++++
 5 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index cffc2c25..a2255c08 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -35,7 +35,12 @@
 
 
 ## Unreleased
+
 ### Added
+
+* New value, `max`, for `[tweak].grapheme-width-method`.
+
+
 ### Changed
 ### Deprecated
 ### Removed
diff --git a/config.c b/config.c
index 68061cc3..0616e87a 100644
--- a/config.c
+++ b/config.c
@@ -2248,7 +2248,7 @@ parse_section_tweak(struct context *ctx)
 
         return value_to_enum(
             ctx,
-            (const char *[]){"wcswidth", "double-width", NULL},
+            (const char *[]){"wcswidth", "double-width", "max", NULL},
             (int *)&conf->tweak.grapheme_width_method);
     }
 
diff --git a/config.h b/config.h
index 652f8422..afe9cf74 100644
--- a/config.h
+++ b/config.h
@@ -256,7 +256,11 @@ struct config {
         enum fcft_scaling_filter fcft_filter;
         bool overflowing_glyphs;
         bool grapheme_shaping;
-        enum {GRAPHEME_WIDTH_WCSWIDTH, GRAPHEME_WIDTH_DOUBLE} grapheme_width_method;
+        enum {
+            GRAPHEME_WIDTH_WCSWIDTH,
+            GRAPHEME_WIDTH_DOUBLE,
+            GRAPHEME_WIDTH_MAX,
+        } grapheme_width_method;
         bool render_timer_osd;
         bool render_timer_log;
         bool damage_whole_window;
diff --git a/doc/foot.ini.5.scd b/doc/foot.ini.5.scd
index 9f5c429b..1b6c4d8c 100644
--- a/doc/foot.ini.5.scd
+++ b/doc/foot.ini.5.scd
@@ -1093,7 +1093,7 @@ any of these options.
 *grapheme-width-method*
 	Selects which method to use when calculating the width
 	(i.e. number of columns) of a grapheme cluster. One of
-	*double-width* and *wcswidth*.
+	*wcswidth*, *double-width* and *max*.
 	
 	*wcswidth* simply adds together the individual width of all
 	codepoints making up the cluster.
@@ -1104,6 +1104,8 @@ any of these options.
 	internally to calculate the width. This results in cursor
 	de-synchronization issues.
 	
+	*max* uses the width of the largest codepoint in the cluster.
+	
 	Default: _wcswidth_
 
 *font-monospace-warn*
diff --git a/vt.c b/vt.c
index 687be912..736a2cfd 100644
--- a/vt.c
+++ b/vt.c
@@ -792,6 +792,10 @@ action_utf8_print(struct terminal *term, wchar_t wc)
                 composed != NULL ? composed->width : base_width;
 
             switch (term->conf->tweak.grapheme_width_method) {
+            case GRAPHEME_WIDTH_MAX:
+                new_cc->width = max(grapheme_width, width);
+                break;
+
             case GRAPHEME_WIDTH_DOUBLE:
                 if (unlikely(wc == 0xfe0f))
                     width = 2;