Abstract:
To convert a DVI file into braille, we have to do these four steps.
- Convert a DVI file to a plain text.
- Lines can be maximaly 32 characters long, so we have to split them and words, which are too long, have to be split too.
- Put Brailles' marks into the text. (Mark the text.)
- Convert the text to a character set which is suitable for printing on a braille printer.
The first step can be done with help of the perl module
DVIParse (available from any CPAN site in the
authors/id/JANPAZ/ directory). The callbacks are defined for each of the DVI instructions in the module. Thus the only thing which you have to do is to program them. For the next step the perl module from the same author, called
hyphenation (available on the same site as the
DVIParse), can be used. There is defined the function
hyphenate in the module. It takes a word as its argument and returns an array of numbers saying where the word can be hyphenated. The third step seems to be the hardest. Firstly we have to know the semantics of the text to put brailles' marks correctly, for example a fraction 3/4. In the plain text the fraction takes 3 lines. The program doesn't know if it is a fraction or if there is underlined number 3 in the text and by chance there is number 4 under it. Each of these possibilities is marked differently. The last step is easy. You can do it with help of the script cstocs (in the case you are converting a czech text).
In my opinion this way is suitable only for converting a plain text not for structured text or text with higher mathematics.
