harfbuzz/src/OT/Layout/GSUB/SingleSubst.hh

104 lines
3.1 KiB
C++

#ifndef OT_LAYOUT_GSUB_SINGLESUBST_HH
#define OT_LAYOUT_GSUB_SINGLESUBST_HH
#include "Common.hh"
#include "SingleSubstFormat1.hh"
#include "SingleSubstFormat2.hh"
namespace OT {
namespace Layout {
namespace GSUB_impl {
struct SingleSubst
{
protected:
union {
HBUINT16 format; /* Format identifier */
SingleSubstFormat1_3<SmallTypes> format1;
SingleSubstFormat2_4<SmallTypes> format2;
#ifndef HB_NO_BEYOND_64K
SingleSubstFormat1_3<MediumTypes> format3;
SingleSubstFormat2_4<MediumTypes> format4;
#endif
} u;
public:
template <typename context_t, typename ...Ts>
typename context_t::return_t dispatch (context_t *c, Ts&&... ds) const
{
if (unlikely (!c->may_dispatch (this, &u.format))) return c->no_dispatch_return_value ();
TRACE_DISPATCH (this, u.format);
switch (u.format) {
case 1: return_trace (c->dispatch (u.format1, std::forward<Ts> (ds)...));
case 2: return_trace (c->dispatch (u.format2, std::forward<Ts> (ds)...));
#ifndef HB_NO_BEYOND_64K
case 3: return_trace (c->dispatch (u.format3, std::forward<Ts> (ds)...));
case 4: return_trace (c->dispatch (u.format4, std::forward<Ts> (ds)...));
#endif
default:return_trace (c->default_return_value ());
}
}
template<typename Iterator,
hb_requires (hb_is_sorted_source_of (Iterator,
const hb_codepoint_pair_t))>
bool serialize (hb_serialize_context_t *c,
Iterator glyphs)
{
TRACE_SERIALIZE (this);
if (unlikely (!c->extend_min (u.format))) return_trace (false);
unsigned format = 2;
unsigned delta = 0;
if (glyphs)
{
format = 1;
hb_codepoint_t mask = 0xFFFFu;
#ifndef HB_NO_BEYOND_64K
if (+ glyphs
| hb_map_retains_sorting (hb_first)
| hb_filter ([] (hb_codepoint_t gid) { return gid > 0xFFFFu; }))
{
format += 2;
mask = 0xFFFFFFu;
}
#endif
auto get_delta = [=] (hb_codepoint_pair_t _)
{ return (unsigned) (_.second - _.first) & mask; };
delta = get_delta (*glyphs);
if (!hb_all (++(+glyphs), delta, get_delta)) format += 1;
}
u.format = format;
switch (u.format) {
case 1: return_trace (u.format1.serialize (c,
+ glyphs
| hb_map_retains_sorting (hb_first),
delta));
case 2: return_trace (u.format2.serialize (c, glyphs));
#ifndef HB_NO_BEYOND_64K
case 3: return_trace (u.format3.serialize (c,
+ glyphs
| hb_map_retains_sorting (hb_first),
delta));
case 4: return_trace (u.format4.serialize (c, glyphs));
#endif
default:return_trace (false);
}
}
};
template<typename Iterator>
static void
SingleSubst_serialize (hb_serialize_context_t *c,
Iterator it)
{ c->start_embed<SingleSubst> ()->serialize (c, it); }
}
}
}
#endif /* OT_LAYOUT_GSUB_SINGLESUBST_HH */