[layout] If lookup has only one subtable, move the forward loop down to subtable
I was hoping to see a nice speedup, but it resulted in a very minor one.
diff --git a/src/hb-ot-layout.cc b/src/hb-ot-layout.cc
index b08637c..f29c52d 100644
--- a/src/hb-ot-layout.cc
+++ b/src/hb-ot-layout.cc
@@ -873,6 +873,29 @@
return ret;
}
+struct hb_apply_forward_context_t
+{
+ inline const char *get_name (void) { return "APPLY_FORWARD"; }
+ static const unsigned int max_debug_depth = HB_DEBUG_APPLY;
+ typedef bool return_t;
+ template <typename T, typename F>
+ inline bool may_dispatch (const T *obj, const F *format) { return true; }
+ template <typename T>
+ inline return_t dispatch (const T &obj) { return apply_forward (c, obj, accel); }
+ static return_t default_return_value (void) { return false; }
+ bool stop_sublookup_iteration (return_t r HB_UNUSED) const { return true; }
+
+ hb_apply_forward_context_t (OT::hb_apply_context_t *c_,
+ const hb_ot_layout_lookup_accelerator_t &accel_) :
+ c (c_),
+ accel (accel_),
+ debug_depth (0) {}
+
+ OT::hb_apply_context_t *c;
+ const hb_ot_layout_lookup_accelerator_t &accel;
+ unsigned int debug_depth;
+};
+
template <typename Proxy>
static inline void
apply_string (OT::hb_apply_context_t *c,
@@ -893,7 +916,15 @@
buffer->clear_output ();
buffer->idx = 0;
- if (apply_forward (c, lookup, accel))
+ bool ret;
+ if (lookup.get_subtable_count () == 1)
+ {
+ hb_apply_forward_context_t c_forward (c, accel);
+ ret = lookup.dispatch (&c_forward);
+ }
+ else
+ ret = apply_forward (c, lookup, accel);
+ if (ret)
{
if (!Proxy::inplace)
buffer->swap_buffers ();
