Filled in GTK+ opentype.c. This is gonna suck as much as it does now...

unix/CMakeLists.txt

@@ -34,6 +34,7 @@ list(APPEND _LIBUI_SOURCES
 	unix/main.c
 	unix/menu.c
 	unix/multilineentry.c
+	unix/opentype.c
 	unix/progressbar.c
 	unix/radiobuttons.c
 	unix/separator.c

unix/opentype.c

@@ -1,8 +1,10 @@
 // 11 may 2017
 #include "uipriv_windows.hpp"
 
+// TODO switch from GINT_FROM_POINTER() and so to a fake GUINT_FROM_POINTER()?
+
 struct uiOpenTypeFeatures {
-	xxxx;
+	GHashTable *tags;
 };
 
 uiOpenTypeFeatures *uiNewOpenTypeFeatures(void)
@@ -10,43 +12,187 @@ uiOpenTypeFeatures *uiNewOpenTypeFeatures(void)
 	uiOpenTypeFeatures *otf;
 
 	otf = uiNew(uiOpenTypeFeatures);
-	xxxx;
+	otf->tags = g_hash_table_new(g_direct_hash, g_direct_equal);
 	return otf;
 }
 
 void uiFreeOpenTypeFeatures(uiOpenTypeFeatures *otf)
 {
-	xxxxxx;
+	g_hash_table_destroy(otf->tags);
 	uiFree(otf);
 }
 
+static void cloneTags(gpointer key, gpointer value, gpointer data)
+{
+	// TODO is there a G_HASH_TABLE()?
+	g_hash_table_replace((GHashTable *) data, key, value);
+}
+
 uiOpenTypeFeatures *uiOpenTypeFeaturesClone(uiOpenTypeFeatures *otf)
 {
 	uiOpenTypeFeatures *out;
 
-	out = uiNew(uiOpenTypeFeatures);
-	xxxxxx;
+	// TODO switch the windows one to use this
+	out = uiNewOpenTypeFeatures();
+	g_hash_table_foreach(otf->tags, cloneTags, out->tags);
 	return out;
 }
 
+static gpointer mkTag(char a, char b, char c, char d)
+{
+	uint32_t tag;
+
+	tag = (((uint32_t) a) & 0xFF) << 24;
+	tag |= (((uint32_t) b) & 0xFF) << 16;
+	tag |= (((uint32_t) c) & 0xFF) << 8;
+	tag |= ((uint32_t) d) & 0xFF;
+	return GINT_TO_POINTER(tag);
+}
+
 void uiOpenTypeFeaturesAdd(uiOpenTypeFeatures *otf, char a, char b, char c, char d, uint32_t value)
 {
+	g_hash_table_replace(otf->tags, mkTag(a, b, c, d), GINT_TO_POINTER(value));
 }
 
 void uiOpenTypeFeaturesRemove(uiOpenTypeFeatures *otf, char a, char b, char c, char d)
 {
+	g_hash_table_remove(otf->tags, mkTag(a, b, c, d));
 }
 
+// TODO should this be before Add and Remove?
+// TODO better name than Get?
 int uiOpenTypeFeaturesGet(uiOpenTypeFeatures *otf, char a, char b, char c, char d, uint32_t *value)
 {
+	gboolean found;
+	gpointer gv;
+
+	found = g_hash_table_lookup_extended(otf->tags,
+		mkTag(a, b, c, d),
+		NULL, &gv);
+	if (!found)
+		return 0;
+	*value = GPOINTER_TO_INT(gv);
+	return 1;
+}
+
+struct otfForEach {
+	uiOpenTypeFeaturesForEachFunc f;
+	void *data;
+	// TODO store continuation status here
+};
+
+static void foreach(gpointer key, gpointer value, gpointer data)
+{
+	struct otfForEach *ofe = (struct otfForEach *) data;
+	uint32_t tag;
+	uint8_t a, b, c, d;
+
+	tag = GPOINTER_TO_INT(key);
+	a = (uint8_t) ((tag >> 24) & 0xFF);
+	b = (uint8_t) ((tag >> 16) & 0xFF);
+	c = (uint8_t) ((tag >> 8) & 0xFF);
+	d = (uint8_t) (tag & 0xFF);
+	// TODO handle return value
+	(*(ofe->f))((char) a, (char) b, (char) c, (char) d, GPOINTER_TO_INT(value), ofe->data);
 }
 
 void uiOpenTypeFeaturesForEach(uiOpenTypeFeatures *otf, uiOpenTypeFeaturesForEachFunc f, void *data)
 {
+	struct otfForEach ofe;
+
+	memset(&ofe, 0, sizeof (struct otfForEach));
+	ofe.f = f;
+	ofe.data = data;
+	g_hash_table_foreach(otf->tags, foreach, &ofe);
+}
+
+static gint tagcmp(gpointer a, gpointer b)
+{
+	return GINT_FROM_POINTER(a) - GINT_FROM_POINTER(b);
+}
+
+static GList *copySortedKeys(GHashTable *tags)
+{
+	GList *k, *copy;
+
+	k = g_hash_table_get_keys(tags);
+	copy = g_list_copy(k);
+	copy = g_list_sort(copy, tagcmp);
+	// TODO do we free k? the docs contradict themselves
+	return copy;
 }
 
 int uiOpenTypeFeaturesEqual(uiOpenTypeFeatures *a, uiOpenTypeFeatures *b)
 {
+	GList *ak, *bk;
+	GList *ai, *bi;
+	guint na, nb;
+	guint i;
+	int equal = 0;
+
+	ak = copySortedKeys(a);
+	bk = copySortedKeys(b);
+
+	na = g_list_length(ak);
+	nb = g_list_length(bk);
+	if (na != nb) {
+		equal = 0;
+		goto out;
+	}
+
+	// TODO use GINT_FROM_POINTER() in these?
+	ai = ak;
+	bi = bk;
+	for (i = 0; i < na; i++) {
+		gpointer av, bv;
+
+		// compare keys
+		// this is why we needed to sort earlier
+		if (ai->data != bi->data) {
+			equal = 0;
+			goto out;
+		}
+		// and compare values
+		av = g_hash_table_lookup(a, ai->data);
+		bv = g_hash_table_lookup(b, bi->data);
+		if (av != bv) {
+			equal = 0;
+			goto out;
+		}
+		ai = ai->next;
+		bi = bi->next;
+	}
+
+	// all good
+	equal = 1;
+
+out:
+	g_list_free(bk);
+	g_list_free(ak);
+	return equal;
 }
 
-// TODO put the internal function to produce a backend object from one here
+// TODO make this a g_hash_table_foreach() function (which requires duplicating code)?
+static int toCSS(char a, char b, char c, char d, uint32_t value, void *data)
+{
+	// TODO is there a G_STRING()?
+	GString *s = (GString *) data;
+
+	// the last trailing comma is removed after foreach is done
+	g_string_append_printf(s, "\"%c%c%c%c\" %" PRIu32 ", ",
+		a, b, c, d, value);
+	// TODO use this
+	return 0;
+}
+
+GString *otfToPangoCSSString(uiOpenTypeFeatures *otf)
+{
+	GString *s;
+
+	s = g_string_new("");
+	uiOpenTypeFeaturesForEach(otf, toCSS, s);
+	if (s->len != 0)
+		// and remove the last comma
+		g_string_truncate(s, s->len - 2);
+	return s;
+}