[kerx] Implement variation-kerning tables (without the variation part)
SFSNDisplay uses these. We just apply the default kern without
variations right now. But at least makes the default kern work.
diff --git a/src/hb-aat-layout-kerx-table.hh b/src/hb-aat-layout-kerx-table.hh
index 9727e39..6425780 100644
--- a/src/hb-aat-layout-kerx-table.hh
+++ b/src/hb-aat-layout-kerx-table.hh
@@ -45,6 +45,21 @@
using namespace OT;
+static inline int
+kerxTupleKern (int value,
+ unsigned int tupleCount,
+ const void *base,
+ hb_aat_apply_context_t *c)
+{
+ if (likely (!tupleCount)) return value;
+
+ unsigned int offset = value;
+ const FWORD *pv = &StructAtOffset<FWORD> (base, offset);
+ if (unlikely (!pv->sanitize (&c->sanitizer))) return 0;
+ return *pv;
+}
+
+
struct KerxSubTableHeader
{
inline bool sanitize (hb_sanitize_context_t *c) const
@@ -65,6 +80,7 @@
{
inline int get_kerning (hb_codepoint_t left, hb_codepoint_t right) const
{
+ if (header.tupleCount) return 0; /* TODO kerxTupleKern */
hb_glyph_pair_t pair = {left, right};
int i = pairs.bsearch (pair);
return i == -1 ? 0 : pairs[i].get_kerning ();
@@ -201,6 +217,9 @@
if (!c->plan->requested_kerning)
return false;
+ if (header.tupleCount)
+ return_trace (false); /* TODO kerxTupleKern */
+
driver_context_t dc (this, c);
StateTableDriver<EntryData> driver (machine, c->buffer, c->font->face);
@@ -236,7 +255,7 @@
unsigned int offset = l + r;
const FWORD *v = &StructAtOffset<FWORD> (&(this+array), offset);
if (unlikely (!v->sanitize (&c->sanitizer))) return 0;
- return *v;
+ return kerxTupleKern (*v, header.tupleCount, this, c);
}
inline bool apply (hb_aat_apply_context_t *c) const
@@ -482,7 +501,7 @@
if (unlikely (hb_unsigned_mul_overflows (offset, sizeof (FWORD32)))) return 0;
const FWORD32 *v = &StructAtOffset<FWORD32> (&(this+t.array), offset * sizeof (FWORD32));
if (unlikely (!v->sanitize (&c->sanitizer))) return 0;
- return *v;
+ return kerxTupleKern (*v, header.tupleCount, &(this+vector), c);
}
else
{
@@ -492,7 +511,7 @@
unsigned int offset = l + r;
const FWORD *v = &StructAtOffset<FWORD> (&(this+t.array), offset * sizeof (FWORD));
if (unlikely (!v->sanitize (&c->sanitizer))) return 0;
- return *v;
+ return kerxTupleKern (*v, header.tupleCount, &(this+vector), c);
}
}
@@ -523,7 +542,9 @@
u.s.rowIndexTable.sanitize (c, this) &&
u.s.columnIndexTable.sanitize (c, this) &&
c->check_range (this, u.s.array)
- ))));
+ )) &&
+ (header.tupleCount == 0 ||
+ c->check_range (this, vector))));
}
struct accelerator_t
@@ -559,8 +580,9 @@
LOffsetTo<UnsizedArrayOf<FWORD>, false> array;
} s;
} u;
+ LOffsetTo<UnsizedArrayOf<FWORD>, false> vector;
public:
- DEFINE_SIZE_STATIC (32);
+ DEFINE_SIZE_STATIC (36);
};
struct KerxTable
@@ -642,9 +664,8 @@
{
bool reverse;
- if (table->u.header.coverage & (KerxTable::CrossStream | KerxTable::Variation) ||
- table->u.header.tupleCount)
- goto skip; /* We do NOT handle cross-stream or variation kerning. */
+ if (table->u.header.coverage & (KerxTable::CrossStream))
+ goto skip; /* We do NOT handle cross-stream. */
if (HB_DIRECTION_IS_VERTICAL (c->buffer->props.direction) !=
bool (table->u.header.coverage & KerxTable::Vertical))
