.de F
.B
.if !"\\$1"" \&\\$1 \\$2 \\$3 \\$4 \\$5 \\$6
..
.de L
.B
.if !"\\$1"" \&\\$1 \\$2 \\$3 \\$4 \\$5 \\$6
..
.de FR
.BR "\\$1" "\\$2" "\\$3" "\\$4" "\\$5" "\\$6"
..
.de LR
.BR "\\$1" "\\$2" "\\$3" "\\$4" "\\$5" "\\$6"
..
.de CW
.ft B
..
.\" This is gross but it avoids relying on internal implementation details
.\" of the -man macros.
.de TF
.IP "" \w'\fB\\$1\ \ \fP'u
.PD0
..
.de EX
.CW
.nf
..
.de EE
.fi
..
.\" delete above this point if your system has F, L, FR, LR, CW and TF macros
.TH FONT 4
.SH NAME
font, subfont \- external format for fonts and subfonts
.SH SYNOPSIS
.nf
.B
#include <libc.h>
.B
#include <libg.h>
.fi
.SH DESCRIPTION
Fonts and subfonts are described in
.IR cachechars (3).
.PP
External fonts are described by a plain text file that can be read using
.I rdfontfile.
The format of the file is a header followed by any number of
subfont range specifications.
The header contains two numbers: the height and the ascent.
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 numbers and a font name.
The numbers are the inclusive range of characters covered by the subfont,
and name specifies the name of an X font suitable for
.IR getsubfont .
The minimum number of a covered range is mapped to the first defined
character of the corresponding subfont.
Each field must be followed by some white space.
Each numeric field may be C-format decimal, octal, or hexadecimal.
.PP
Subfonts may be loaded using
.IR getsubfont ,
see
.IR graphics (3).
.SH BUGS
Some X font names contain spaces which will terminate the field.
For some fonts this can be worked around by replacing the spaces
with
.L `*'
characters in an attempt to fool the X font name pattern matching mechanism.
.SH "SEE ALSO"
.IR graphics (3),
.IR bitblt (3),
.IR cachechars (3).