1map entry:cyberb @ Unicode @ <cyberbit.ttf PidEid = 3, 1 means cyberb < INFIX > = >look at Unicode.sfd = >find the mapping = >charcode = >PidEid = 3, 1 = >glyphs eg cyberb01 = >subfont 01 in Unicode.sfd = >charcodes Infix can be anything, thus the question:given a tfm name, how to find out
2    whether this is a subfont ?
3    It is safe to limit the infix to be composed from hexadecimal digits only ?
4    If so, one possibility is : (1)
5    while last
6    -char -of - tfmname is a hexdigit
7    do
8         remove the last char from tfmname
9        do
10         a lookup for the tfmname
11                if found an entry with subfont flag then break enddo(2)
12             Or, when a map entry with subfont flag is scanned,
13                let pdftex create all the relevant entries.
14                Which may be a safer and faster solution(but wastes more memory)
15
16
17           Let 's do (2), as infix can be any word.
18
19
20
21Implementation:
22
23- let' s have a map entry : cyberb @ Unicode @ <cyberbit.ttf PidEid = 3, 1 - actions:
24            -read Unicode.sfd
25                - create corresponding sfd mapping like("01", "Unicode") =
26                >long[256]
27            - added those subfont to an AVL tree -
28                create map entries for cyberb01-- cyberbff,
29                each has a pointer to the corresponding sfd mapping entry -
30                extended attributes for map entry:-Pid - Eid - sfd_map -
31                sfd_mapping:-name:sfd name, eg "Unicode" - infix,
32                eg "01" - mapping:long[256]
33
34-how to find out whether a sfd has been loaded:
35                    -lookup for any entry with the given sfd
36                    name - functions:-load_sfd -
37                    lookup_subfont -
38                    extend reading map entries -
39                    when writting ttf:-if re - encoded-- >
40                    process like in case of type1 fonts -
41                    if PidEid is being used:-read cmap
42                    tables:store(ttfname, pid, eid)
43    -search for used chars - use sfd to find the charcodes - look into cmap to
44