From cc1c4fdf88f6953dcd07fb42ee963404657cdef4 Mon Sep 17 00:00:00 2001 From: Behdad Esfahbod Date: Mon, 10 Sep 2018 16:36:05 +0200 Subject: [PATCH] Respect user's wish if they set rand feature manually Except if the set it to 1, which would mean "randomize"... Ugly. --- src/hb-ot-layout-gsub-table.hh | 30 ++++++++++++++++-------------- 1 file changed, 16 insertions(+), 14 deletions(-) diff --git a/src/hb-ot-layout-gsub-table.hh b/src/hb-ot-layout-gsub-table.hh index ae679441b..255a2827e 100644 --- a/src/hb-ot-layout-gsub-table.hh +++ b/src/hb-ot-layout-gsub-table.hh @@ -534,24 +534,26 @@ struct AlternateSet if (unlikely (!count)) return_trace (false); - if (c->random) + hb_mask_t glyph_mask = c->buffer->cur().mask; + hb_mask_t lookup_mask = c->lookup_mask; + + /* Note: This breaks badly if two features enabled this lookup together. */ + 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) { c->random_state = (0x5DEECE66Dull * c->random_state + 11) & (((uint64_t) 1 << 48) - 1); - c->replace_glyph (alternates[(c->random_state >> 32) % count]); + alt_index = (c->random_state >> 32) % count + 1; } - else - { - hb_mask_t glyph_mask = c->buffer->cur().mask; - hb_mask_t lookup_mask = c->lookup_mask; - /* Note: This breaks badly if two features enabled this lookup together. */ - 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); - - c->replace_glyph (alternates[alt_index - 1]); - } + c->replace_glyph (alternates[alt_index - 1]); return_trace (true); }