On 22-2-2011 4:22, Ulrike Fischer wrote:
Hello,
Khaled had another idea to manipulate (reencode) fonts: He suggested to put a function in fonts.trigger. (Example below). I have some questions regarding this example:
1. Is there a basic flaw in the idea?
When triggers are done, there are only empty entries in the characters table so swapping them has no effect. You can add info to them but some entries in them will be added when scaling takes place.
2. Is the interface more or less stable or will it probably change in the future?
the triggers interface will stay
If not 3. which tables/values in tfmdata must be copied/reassigned beside the indices information? (There seem to be quite a lot informations more than once in tfmdata. E.g. I find the boundingbox in two places (descriptions and shared.otfdata.glyphs)).
they are the same (descriptions is the unicode ordering of glyphs but the subtables are shared, and best don't mess with those subtables as they can be shared as well) you probably don't have to change anything else as tex only works with the tfm data (in node mode otf data is used but chess is unlikely to be influenced by node mode)
4. Which tables/values must be created if I try to move a char to a place which is currently empty (like the "z" in the example)?
see above, for tex only the tfmdata counts so no other data has to be created (unless you have kerns in which case you need to adapt all character entries that kern with that glyph)
5. What is the recommanded lua-code to copy/reassign/remap the tables? Does a library or some helper functions exist which would make it easier to move the tables around?
For basemode reencoding you can use the changed subtable: \starttext \directlua{ local function chess(tfmdata,value) if value then tfmdata.changed[75] = 81 tfmdata.changed[81] = 75 end end table.insert(fonts.triggers,"chess") fonts.initializers.base.otf.chess = chess } \start \font\TestA="file:SkakNew-Figurine.otf:chess=yes" \TestA\char75 \char81 \par \font\TestB="file:SkakNew-Figurine.otf:chess=no" \TestB\char75 \char81 \par \stop \stoptext ----------------------------------------------------------------- Hans Hagen | PRAGMA ADE Ridderstraat 27 | 8061 GH Hasselt | The Netherlands tel: 038 477 53 69 | voip: 087 875 68 74 | www.pragma-ade.com | www.pragma-pod.nl -----------------------------------------------------------------