From: Ben Harris <bjh21@bjh21.me.uk>
Date: Tue, 7 Jan 2025 22:37:19 +0000 (+0000)
Subject: Generate ss0X substitutions less cleverly
X-Git-Tag: bedstead-3.251~44
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~bjharris/git?a=commitdiff_plain;h=7658a55c8622beb8ab579a26f5447e5d6b3e8520;p=bedstead.git

Generate ss0X substitutions less cleverly

These substitutions are not generated from the glyphs table, but are
specified statically.  Rather than taking a table and transforming it
into XML with C, we could just put the static XML in a string, which
is much simpler.  To avoid excessive simplicity, the string is
generated by a pile of preprocessor macros.

This causes no change to the output OTFs.
---

diff --git a/bedstead.c b/bedstead.c
index a3144f0..8632cae 100644
--- a/bedstead.c
+++ b/bedstead.c
@@ -2723,7 +2723,6 @@ static struct alt_sub_override {
 	{ "ugrave", { "ugrave.roundjoined", "ugrave.sc" } },
 };
 
-#define MAXSUBS 10
 static struct gsub_feature {
 	char const *tag;
 #define SCRIPT_DFLT 0x01
@@ -2731,7 +2730,7 @@ static struct gsub_feature {
 #define SCRIPT_ALL  0x03
 	unsigned int scripts;
 	char const *suffix; /* NULL for all alternative glyphs. */
-	char const *subs[MAXSUBS]; /* Individual character substitutions. */
+	char const *xml; /* Individual character substitutions. */
 	char const *name;
 	struct alt_sub_override const *overrides;
 	int noverrides;
@@ -2741,19 +2740,26 @@ static struct gsub_feature {
 	{ "smcp", SCRIPT_LATN, .suffix = ".sc" },
 	{ "c2sc", SCRIPT_LATN, .suffix = ".c2sc" },
 	{ "rtlm", SCRIPT_ALL, .suffix = ".rtlm" },
+#define SINGLESUB(in, out) "<Substitution in='" in "' out='" out "'/>\n"
+#define SUFFIXSUB(base, suffix) SINGLESUB(base, base suffix)
 	{ "ss01", SCRIPT_ALL, .name = "SAA5051",
-	  .subs = { "comma.left", "period.large", "colon.leftsmall",
-		    "semicolon.left", "question.open",
-		    "D.serif", "J.narrow", "L.narrow",
-		    "j.serif", "t.small" } },
+	  .xml = "<SingleSubst>\n" SUFFIXSUB("comma", ".left")
+	  SUFFIXSUB("period", ".large") SUFFIXSUB("colon", ".leftsmall")
+	  SUFFIXSUB("semicolon", ".left") SUFFIXSUB("question", ".open")
+	  SUFFIXSUB("D", ".serif") SUFFIXSUB("J", ".narrow")
+	  SUFFIXSUB("L", ".narrow") SUFFIXSUB("j", ".serif")
+	  SUFFIXSUB("t", ".small") "</SingleSubst>\n" },
 	{ "ss02", SCRIPT_ALL, .name = "SAA5052",
-	  .subs = { "comma.left", "period.large", "colon.leftsmall",
-		    "semicolon.left", "question.open",
-		    "D.narrow", "J.narrow", "L.narrow",
-		    "j.serif", "t.small" } },
+	  .xml = "<SingleSubst>\n" SUFFIXSUB("comma", ".left")
+	  SUFFIXSUB("period", ".large") SUFFIXSUB("colon", ".leftsmall")
+	  SUFFIXSUB("semicolon", ".left") SUFFIXSUB("question", ".open")
+	  SUFFIXSUB("D", ".narrow") SUFFIXSUB("J", ".narrow")
+	  SUFFIXSUB("L", ".narrow") SUFFIXSUB("j", ".serif")
+	  SUFFIXSUB("t", ".small") "</SingleSubst>\n" },
 	{ "ss04", SCRIPT_ALL, .name = "SAA5054",
-	  .subs = { "ugrave.roundjoined", "ocircumflex.large",
-		    "ccedilla.angular" } },
+	  .xml = "<SingleSubst>\n" SUFFIXSUB("ugrave", ".roundjoined")
+	  SUFFIXSUB("ocircumflex", ".large") SUFFIXSUB("ccedilla", ".angular")
+	  "</SingleSubst>\n" },
 	{ "ss14", SCRIPT_ALL,  ".sep4", .name = "4-cell separated graphics" },
 	{ "ss16", SCRIPT_ALL,  ".sep6", .name = "6-cell separated graphics" },
 };
@@ -3634,21 +3640,11 @@ dogsub(void)
 			printf("     <SingleSubst>\n");
 			dosinglesubs(gsub_features[i].suffix);
 			printf("     </SingleSubst>\n");
-		} else if (gsub_features[i].subs[0] != NULL) {
-			/* Stylistic set of pick and mix glyphs. */
+		} else if (gsub_features[i].xml != NULL) {
+			/* Raw XML for a substitution. */
 			TTXI("LookupType", 1);
 			TTXI("LookupFlag", 0);
-			printf("     <SingleSubst>\n");
-			for (int j = 0; j < MAXSUBS; j++) {
-				char const *sub = gsub_features[i].subs[j];
-				if (sub == NULL) break;
-				char *dot = strchr(sub, '.');
-				assert(dot != NULL);
-				printf("      "
-				       "<Substitution in='%.*s' out='%s'/>\n",
-				       (int)(dot - sub), sub, sub);
-			}
-			printf("     </SingleSubst>\n");
+			printf("%s", gsub_features[i].xml);
 		} else {
 			/* All possible alternative glyphs. */
 			TTXI("LookupType", 3);