From f7094e7c757e6d03610f45ab70db6eae97ed4937 Mon Sep 17 00:00:00 2001
From: Ben Harris <bjh21@bjh21.me.uk>
Date: Wed, 6 Nov 2024 23:05:54 +0000
Subject: [PATCH] Skeleton of GPOS support

---
 bedstead.c | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/bedstead.c b/bedstead.c
index f1d073c..7209cb1 100644
--- a/bedstead.c
+++ b/bedstead.c
@@ -2662,6 +2662,7 @@ static void docmap(int pid, int eid, int format);
 static void dogsub(void);
 static void doaltsubs(void);
 static void dosinglesubs(char const *suffix);
+static void dogpos(void);
 static void glyph_complement(void);
 static void bdf_gen(int size);
 static void doglyph(struct glyph *);
@@ -3127,6 +3128,7 @@ main(int argc, char **argv)
 		       (int)realglyph(&glyphs[i])->left_sidebearing);
 	printf(" </hmtx>\n");
 	dogsub();
+	dogpos();
 	printf("</ttFont>\n");
 	return EXIT_SUCCESS;
 }
@@ -3406,6 +3408,40 @@ dosinglesubs(char const *suffix)
 			       glyphs[i].name, glyphs[i].name);
 }
 
+
+static void
+dogpos(void)
+{
+
+	/* We only support one 'GPOS' lookup, 'palt'. */
+	printf(" <GPOS>\n");
+	TTXS(Version, "0x00010000");
+	printf("  <ScriptList>\n");
+	printf("   <ScriptRecord>\n");
+	TTXS(ScriptTag, "DFLT");
+	printf("    <Script><DefaultLangSys>\n");
+	TTXI(ReqFeatureIndex, 0xffff); /* No required feature. */
+	TTXI(FeatureIndex, 0);
+	printf("    </DefaultLangSys></Script>\n");
+	printf("   </ScriptRecord>\n");
+	printf("  </ScriptList>\n");
+	printf("  <FeatureList>\n");
+	printf("   <FeatureRecord>\n");
+	TTXS(FeatureTag, "palt");
+	printf("    <Feature>\n");
+	TTXI(LookupListIndex, 0);
+	printf("    </Feature>\n");
+	printf("   </FeatureRecord>\n");
+	printf("  </FeatureList>\n");
+	printf("  <LookupList>\n");
+	printf("   <Lookup>\n");
+	TTXI(LookupType, 1);
+	TTXI(LookupFlag, 0);
+	printf("   </Lookup>\n");
+	printf("  </LookupList>\n");
+	printf(" </GPOS>\n");
+}
+
 /* Emit a charstring for a glyph. */
 static void
 doglyph(struct glyph *g)
-- 
2.30.2