web2c: tftopl invocation
11.6 TFtoPL: TeX font metric to property list conversion
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TFtoPL translates a TeX font metric (TFM, ⇒(dvips)Metric files)
file (as output by Metafont, for example) to "property list format" (a
list of parenthesized items describing the font) that humans can edit or
read. This program is mostly used by people debugging TeX
implementations, writing font utilities, etc. Synopsis:
tftopl [OPTION]... TFMNAME[.tfm] [PLFILE[.pl]]
The font TFMNAME (extended with '.tfm' if necessary) is searched for
in the usual places (⇒(kpathsea)Supported file formats). To see
all the relevant paths, set the environment variable 'KPATHSEA_DEBUG' to
'-1' before running the program.
If PLFILE (which is extended with '.pl' if necessary) is not
specified, the property list file is written to standard output. The
property list file can be converted back to TFM format by the companion
program TFtoPL (see the next section).
The program accepts the following option, as well as the standard
'-verbose', '-help' and '-version' (⇒Common options):
'-charcode-format=TYPE'
Output character codes in the PL file according to TYPE: either
'octal' or 'ascii'. Default is 'ascii' for letters and digits,
octal for all other characters. Exception: if the font's coding
scheme starts with 'TeX math sy' or 'TeX math ex', all character
codes are output in octal.
In 'ascii' format, character codes that correspond to graphic
characters, except for left and right parentheses, are output as a
'C' followed by the single character: 'C K', for example. In octal
format, character codes are output as the letter 'O' followed by
octal digits, as in 'O 113' for 'K'.
'octal' format is useful for symbol and other non-alphabetic fonts,
where using ASCII characters for the character codes is merely
confusing.
As an example of the output, here is the (abridged) property list
translation of 'cmr10.tfm':
(FAMILY CMR)
(FACE O 352)
(CODINGSCHEME TEX TEXT)
(DESIGNSIZE R 10.0)
(COMMENT DESIGNSIZE IS IN POINTS)
(COMMENT OTHER SIZES ARE MULTIPLES OF DESIGNSIZE)
(CHECKSUM O 11374260171)
(FONTDIMEN
(SLANT R 0.0)
(SPACE R 0.333334)
(STRETCH R 0.166667)
(SHRINK R 0.111112)
(XHEIGHT R 0.430555)
(QUAD R 1.000003)
(EXTRASPACE R 0.111112)
)
(LIGTABLE
...
(LABEL C f)
(LIG C i O 14)
(LIG C f O 13)
(LIG C l O 15)
(KRN O 47 R 0.077779)
(KRN O 77 R 0.077779)
(KRN O 41 R 0.077779)
(KRN O 51 R 0.077779)
(KRN O 135 R 0.077779)
(STOP)
...
)
...
(CHARACTER C f
(CHARWD R 0.305557)
(CHARHT R 0.694445)
(CHARIC R 0.077779)
(COMMENT
(LIG C i O 14)
(LIG C f O 13)
(LIG C l O 15)
(KRN O 47 R 0.077779)
(KRN O 77 R 0.077779)
...
)
)
...
As you can see, the general format is a list of parenthesized
"properties", nested where necessary.
* The first few items ('FAMILY', 'FACE', and so on) are the so-called
"headerbyte" information from Metafont, giving general information
about the font.
* The 'FONTDIMEN' property defines the TeX '\fontdimen' values.
* The 'LIGTABLE' property defines the ligature and kerning table.
'LIG' properties define ligatures: in the example above, an 'f' (in
the 'LABEL') followed by an 'i' is a ligature, i.e., a typesetting
program like TeX replaces those two consecutive characters by the
character at position octal '014 in the current font--presumably
the 'fi' ligature. 'KRN' properties define kerns: if an 'f' is
followed by character octal '047 (an apostrophe), TeX inserts a
small amount of space between them: 0.077779 times the design size
the font was loaded at (about three-quarters of a printer's point
by default in this case, or .001 inches).
* The 'CHARACTER' property defines the dimensions of a character: its
width, height, depth, and italic correction, also in design-size
units, as explained in the previous item. For our example 'f', the
depth is zero, so that property is omitted. TFtoPL also inserts
any kerns and ligatures for this character as a comment.