Make --features rand=1 available to the user
Use rand=255 to mean "randomize".
Part of https://github.com/harfbuzz/harfbuzz/pull/803
diff --git a/src/hb-ot-layout-gsub-table.hh b/src/hb-ot-layout-gsub-table.hh
index 255a282..dfa5097 100644
--- a/src/hb-ot-layout-gsub-table.hh
+++ b/src/hb-ot-layout-gsub-table.hh
@@ -541,18 +541,15 @@
unsigned int shift = hb_ctz (lookup_mask);
unsigned int alt_index = ((lookup_mask & glyph_mask) >> shift);
- if (unlikely (alt_index > count || alt_index == 0)) return_trace (false);
-
- /* This is ugly... If alt_index is 1, we take it as "on", and randomize
- * feature if it is the rand feature. If it's > 1, it's a user-set value
- * for sure, so respect it. So, user cannot set rand=1 and expect it to
- * choose the first alternate... */
- if (alt_index == 1 && c->random)
+ /* If alt_index is MAX, randomize feature if it is the rand feature. */
+ if (alt_index == HB_OT_MAP_MAX_VALUE && c->random)
{
c->random_state = (0x5DEECE66Dull * c->random_state + 11) & (((uint64_t) 1 << 48) - 1);
alt_index = (c->random_state >> 32) % count + 1;
}
+ if (unlikely (alt_index > count || alt_index == 0)) return_trace (false);
+
c->replace_glyph (alternates[alt_index - 1]);
return_trace (true);
