Fix ToUnicode with reverse CMap lookup

When dvipdfmx is provided a regular CMap in the following format:

<unicode codepoint> cid

We can try to utilize the data and do a reverse lookup when all we
know is the cids used.

Initially, when parsing the cmap specified, we build a reverseMap
which maps CID to the first Unicode codepoint it corresponds to.
(Which is pretty much the reverse of CMap_decode().)

Since this cmap is already parsed when we create the fontmap cache,
we can just pass the cmap_id all the way down to
otf_create_ToUnicode_stream() and get CMap* back from this cmap_id.

Second, we refactor create_ToUnicode_cmap{4, 12}() functions into
one create_ToUnicode_cmap() and combine the common code.

In the third step, in create_ToUnicode_cmap() we try to see if the
font is indeed a CFF font (with CID-keyed), and we do have a cmap,
we can use the newly added CMap_reverse_decode() to convert all
used cids back to Unicode codepoints. With that mapping information
we can successfully create the ToUnicode PDF stream we needed.

git-svn-id: svn://tug.org/texlive/trunk@34831 c570f23f-e606-0410-a88d-b1316a301751

0 files changed, 0 insertions, 0 deletions