From: Ben Harris <bjh21@bjh21.me.uk>
Date: Tue, 14 Jan 2025 23:29:48 +0000 (+0000)
Subject: Don't emit multiple subtables for 'cv31'
X-Git-Tag: bedstead-3.251~35
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~bjharris/git?a=commitdiff_plain;h=b0f67aa3eff48d769871da07485f7fab2b0c2f98;p=bedstead.git

Don't emit multiple subtables for 'cv31'

I was accidentally emitting a separate <AlternateSubst> element for
each base character, which worked but was unnecessary.  A single
<AlternateSubst> for the whole lookup will make for a smaller font
file and probably faster lookups as well.
---

diff --git a/bedstead.c b/bedstead.c
index fdf0252..b84b42c 100644
--- a/bedstead.c
+++ b/bedstead.c
@@ -2777,11 +2777,9 @@ static struct gsub_feature {
 #define ALT3(a, b, c) ALT1(a) ALT2(b, c)
 #define ALTSET(g, a) "<AlternateSet glyph='" g "'>" a "</AlternateSet>\n"
 #define ALTSUB(x) "<AlternateSubst>\n" x "</AlternateSubst>\n"
-#define CROSSALT2(a, b) ALTSUB(ALTSET(a, ALT2(a, b)) ALTSET(b, ALT2(a, b)))
-#define CROSSALT3(a, b, c)			\
-	ALTSUB(ALTSET(a, ALT3(a, b, c))		\
-	       ALTSET(b, ALT3(a, b, c))		\
-	       ALTSET(c, ALT3(a, b, c)))
+#define CROSSALT2(a, b) ALTSET(a, ALT2(a, b)) ALTSET(b, ALT2(a, b))
+#define CROSSALT3(a, b, c) ALTSET(a, ALT3(a, b, c)) ALTSET(b, ALT3(a, b, c)) \
+	ALTSET(c, ALT3(a, b, c))
 #define CV2(base, a) CROSSALT2(base, base a)
 #undef VAR2
 #define VAR2 CV2
@@ -2790,20 +2788,32 @@ static struct gsub_feature {
 	 * 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 = CV12 },
-	{ "cv14", SCRIPT_ALL, .name = "full-stop variants", .xml = CV14 },
-	{ "cv26", SCRIPT_ALL, .name = "colon variants", .xml = CV26 },
-	{ "cv27", SCRIPT_ALL, .name = "semicolon variants", .xml = CV27 },
-	{ "cv31", SCRIPT_ALL, .name = "question-mark variants", .xml = CV31 },
+	{ "cv12", SCRIPT_ALL, .name = "comma variants",
+	  .xml = ALTSUB(CV12) },
+	{ "cv14", SCRIPT_ALL, .name = "full-stop variants",
+	  .xml = ALTSUB(CV14) },
+	{ "cv26", SCRIPT_ALL, .name = "colon variants",
+	  .xml = ALTSUB(CV26) },
+	{ "cv27", SCRIPT_ALL, .name = "semicolon variants",
+	  .xml = ALTSUB(CV27) },
+	{ "cv31", SCRIPT_ALL, .name = "question-mark variants",
+	  .xml = ALTSUB(CV31) },
 	{ "cv38", SCRIPT_ALL, .name = "capital-D variants",
-	  .xml = CV3("D", ".serif", ".narrow") },
-	{ "cv42", SCRIPT_ALL, .name = "capital-J variants", .xml = CV42 },
-	{ "cv44", SCRIPT_ALL, .name = "capital-L variants", .xml = CV44 },
-	{ "cv61", SCRIPT_ALL, .name = "small-u-grave variants", .xml = CV61 },
-	{ "cv74", SCRIPT_ALL, .name = "small-j variants", .xml = CV74 },
-	{ "cv79", SCRIPT_ALL, .name = "small-o variants", .xml = CV79 },
-	{ "cv84", SCRIPT_ALL, .name = "small-t variants", .xml = CV84 },
-	{ "cv96", SCRIPT_ALL, .name = "cedilla variants", .xml = CV96 },
+	  .xml = ALTSUB(CV3("D", ".serif", ".narrow")) },
+	{ "cv42", SCRIPT_ALL, .name = "capital-J variants",
+	  .xml = ALTSUB(CV42) },
+	{ "cv44", SCRIPT_ALL, .name = "capital-L variants",
+	  .xml = ALTSUB(CV44) },
+	{ "cv61", SCRIPT_ALL, .name = "small-u-grave variants",
+	  .xml = ALTSUB(CV61) },
+	{ "cv74", SCRIPT_ALL, .name = "small-j variants",
+	  .xml = ALTSUB(CV74) },
+	{ "cv79", SCRIPT_ALL, .name = "small-o variants",
+	  .xml = ALTSUB(CV79) },
+	{ "cv84", SCRIPT_ALL, .name = "small-t variants",
+	  .xml = ALTSUB(CV84) },
+	{ "cv96", SCRIPT_ALL, .name = "cedilla variants",
+	  .xml = ALTSUB(CV96) },
 	{ "ss14", SCRIPT_ALL,  ".sep4", .name = "4-cell separated graphics" },
 	{ "ss16", SCRIPT_ALL,  ".sep6", .name = "6-cell separated graphics" },
 };