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FONT(6)                          Games Manual                          FONT(6)

       font, subfont - external format for fonts and subfonts

       #include <&lt;libg.h>&gt;

       Fonts and subfonts are described in cachechars(2).

       External  fonts  are  described  by  a plain text file that can be read
       using rdfontfile.  The format of the file is a header followed  by  any
       number  of  subfont range specifications.  The header contains two num-
       bers: the height and the ascent, both in pixels.   The  height  is  the
       inter-line  spacing  and the ascent is the distance from the top of the
       line to the baseline.  These numbers are chosen to display consistently
       all  the  subfonts of the font.  A subfont range specification contains
       two or three numbers and a file name.  The numbers  are  the  inclusive
       range  of  characters covered by the subfont, with an optional starting
       position within the subfont, and the file name names an  external  file
       suitable  for  rdsubfontfile.  The minimum number of a covered range is
       mapped to the specified starting position (default zero) of the  corre-
       sponding  subfont.   If  the  subfont  file  name does not begin with a
       slash, it is taken relative to the directory containing the font  file.
       Each  field  must  be followed by some white space.  Each numeric field
       may be C-format decimal, octal, or hexadecimal.

       External subfonts are represented in a more rigid format  that  can  be
       read  and  written  using  rdsubfontfile and wrsubfontfile (see subfal-
       loc(2)).  The format for subfont files is: a bitmap containing  charac-
       ter  images, followed by a subfont header, followed by character infor-
       mation.  The bitmap has the format for external bitmap files  described
       in bitmap(6).  The subfont header has 3 decimal strings: n, height, and
       ascent.  Each number is right-justified and blank padded in 11  charac-
       ters,  followed  by a blank.  The character info consists of n+1 6-byte
       entries, each giving the Fontchar x (2 bytes, low  order  byte  first),
       top, bottom, left, and width.  The x field of the last Fontchar is used
       to calculate the bitmap width of  the  previous  character;  the  other
       fields in the last Fontchar are irrelevant.

       Note  that  the convention of using the character with value zero (NUL)
       to represent characters of zero width (see bitblt(2)) means that  fonts
       should have, as their zeroth character, one with non-zero width.

              font directories

       graphics(2), bitblt(2), cachechars(2), subfalloc(2)