[GPOS] If an Anchor offset is NULL, return false

If in a MarkPos table, a base has no anchor for a particular mark class,
return NULL such that the subsequent subtables get a chance at it.

Test case:
hb-shape ./EBGaramond12-Regular.otf ἂ --features="ss20","smcp"
This commit is contained in:
Behdad Esfahbod 2013-01-08 16:15:46 -06:00
parent e5dbf39900
commit e95e031b56
2 changed files with 20 additions and 4 deletions

View File

@ -616,10 +616,20 @@ struct Index : USHORT {
DEFINE_NULL_DATA (Index, "\xff\xff");
/* Offset to a table, same as uint16 (length = 16 bits), Null offset = 0x0000 */
typedef USHORT Offset;
struct Offset : USHORT
{
inline bool is_null (void) const { return 0 == *this; }
public:
DEFINE_SIZE_STATIC (2);
};
/* LongOffset to a table, same as uint32 (length = 32 bits), Null offset = 0x00000000 */
typedef ULONG LongOffset;
struct LongOffset : ULONG
{
inline bool is_null (void) const { return 0 == *this; }
public:
DEFINE_SIZE_STATIC (4);
};
/* CheckSum */

View File

@ -336,8 +336,10 @@ struct Anchor
struct AnchorMatrix
{
inline const Anchor& get_anchor (unsigned int row, unsigned int col, unsigned int cols) const {
inline const Anchor& get_anchor (unsigned int row, unsigned int col, unsigned int cols, bool *found) const {
*found = false;
if (unlikely (row >= rows || col >= cols)) return Null(Anchor);
*found = !matrix[row * cols + col].is_null ();
return this+matrix[row * cols + col];
}
@ -392,7 +394,11 @@ struct MarkArray : ArrayOf<MarkRecord> /* Array of MarkRecords--in Coverage orde
unsigned int mark_class = record.klass;
const Anchor& mark_anchor = this + record.markAnchor;
const Anchor& glyph_anchor = anchors.get_anchor (glyph_index, mark_class, class_count);
bool found;
const Anchor& glyph_anchor = anchors.get_anchor (glyph_index, mark_class, class_count, &found);
/* If this subtable doesn't have an anchor for this base and this class,
* return false such that the subsequent subtables have a chance at it. */
if (unlikely (!found)) return TRACE_RETURN (false);
hb_position_t mark_x, mark_y, base_x, base_y;