From: Ben Harris <bjh21@bjh21.me.uk>
Date: Mon, 13 Jan 2025 21:14:36 +0000 (+0000)
Subject: Rename two 'cvXX' features based on SAA5054 shapes
X-Git-Tag: bedstead-3.251~38
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~bjharris/git?a=commitdiff_plain;h=237d5f515d77c545e09c35cf7603e82e8aece94d;p=bedstead.git

Rename two 'cvXX' features based on SAA5054 shapes

The features that generate the variant ocircumflex and ccedilla glyphs
are now treated a being variants of lower-case 'o' and cedilla
respectively.  Unlike the SAA5051/2 variants, we don't yet have
variants of their base glyphs.  Indeed, for the lower-case 'o' we
probably never will, because the variant is "larger accented versions"
so the unaccented version wouldn't change.

I haven't done anything about the weird SAA5054 ugrave because I'm not
sure there's any real design principle behind it.

I've also added a comment explaining the numbering of 'cvXX' features.
---

diff --git a/bedstead-faces.css b/bedstead-faces.css
index 88d0c3b..4db70b6 100644
--- a/bedstead-faces.css
+++ b/bedstead-faces.css
@@ -123,11 +123,11 @@
         ugrave-roundjoined: 61 2;
         j-default: 74 1;
         j-serif: 74 2;
+        o-default: 79 1;
+        o-large: 79 2;
         t-default: 84 1;
         t-small: 84 2;
-        ocircumflex-default: 92 1;
-        ocircumflex-large: 92 2;
-        ccedilla-default: 94 1;
-        ccedilla-angular: 94 2;
+        cedilla-default: 96 1;
+        cedilla-angular: 96 2;
     }
 }
diff --git a/bedstead.c b/bedstead.c
index a73a65b..bbae63d 100644
--- a/bedstead.c
+++ b/bedstead.c
@@ -2772,6 +2772,10 @@ static struct gsub_feature {
 	       ALTSET(c, ALT3(a, b, c)))
 #define CV2(base, a) CROSSALT2(base, base a)
 #define CV3(base, a, b) CROSSALT3(base, base a, base b)
+	/*
+	 * Where possible, Character Variant features have numbers
+	 * that are 32 less than the ASCII code of the base character.
+	 */
 	{ "cv12", SCRIPT_ALL, .name = "comma variants",
 	  .xml = CV2("comma", ".left") },
 	{ "cv14", SCRIPT_ALL, .name = "full-stop variants",
@@ -2792,11 +2796,11 @@ static struct gsub_feature {
 	  .xml = CV2("ugrave",".roundjoined") },
 	{ "cv74", SCRIPT_ALL, .name = "small-j variants",
 	  .xml = CV2("j", ".serif") },
+	{ "cv79", SCRIPT_ALL, .name = "small-o variants",
+	  .xml = CV2("ocircumflex", ".large") },
 	{ "cv84", SCRIPT_ALL, .name = "small-t variants",
 	  .xml = CV2("t", ".small") },
-	{ "cv92", SCRIPT_ALL, .name = "small-o-circumflex variants",
-	  .xml = CV2("ocircumflex", ".large") },
-	{ "cv94", SCRIPT_ALL, .name = "small-c-cedilla variants",
+	{ "cv96", SCRIPT_ALL, .name = "cedilla variants",
 	  .xml = CV2("ccedilla", ".angular") },
 	{ "ss14", SCRIPT_ALL,  ".sep4", .name = "4-cell separated graphics" },
 	{ "ss16", SCRIPT_ALL,  ".sep6", .name = "6-cell separated graphics" },