Major update to distinguish between unsorted and overlapped segments
for cmap format 4. For overlapped but sorted segments, which is
previously considered unsorted, we still use binary search.
* src/sfnt/ttcmap.h (struct TT_CMapRec_): Replace `unsorted' by
`flags'.
(TT_CMAP_FLAG_UNSORTED, TT_CMAP_FLAG_OVERLAPPED): New macros.
* src/sfnt/ttcmap.c (OPT_CMAP4): Removed as it is always defined.
(struct TT_CMap4Rec_): Remove `old_charcode' and `table_length'.
(tt_cmap4_reset): Removed.
(tt_cmap4_init): Updated accordingly.
(tt_cmap4_next): Updated accordingly.
Take care of overlapped segments.
(tt_cmap4_validate): Make sure the subtable is large enough.
Do not check glyph_ids because some fonts set the length wrongly.
Also, when all segments have offset 0, glyph_ids is always invalid. It
does not cause any problem so far only because the check misses
equality.
Distinguish between unsorted and overlapped segments.
(tt_cmap4_char_map_linear, tt_cmap4_char_map_binary): New functions to
do "charcode => glyph index" by linear/binary search.
(tt_cmap4_char_index, tt_cmap4_char_next): Use
tt_cmap4_char_map_linear and tt_cmap4_char_map_binary.
(tt_face_build_cmaps): Treat the return value of validator as flags
for cmap.
3 files changed