AT&T UNIX™PC Unix System V Users Manual - tenox

FONT ( 4 ) (AT&T UNIX PC only ) FONT ( 4)
NAME
font - font file format
DESCRIPTION
A font is a collection of 96 variably-sized graphics. A font exists
first on disk as a "font file." Font files are loaded into the kernel
via the WIOCLFONT (see window(1)) or SYSL_LFONT (see syslocal(2))
ioctl . Each font file has three sections: first, a header
containing information about the font as a whole; second, a 96entry
table describing each of up to 96 characters in the font; and
third, a variable number of "minirasters," each an array of 16-bit
words containing the pixel definition of each character. The font
file format is given below:
#define FMAGIC 0616
#define FNTSIZE 96
struct fntdef
{
long
unsigned char
char
char
char
char
struct f cdef
unsigned short
};
};
/* font magic number *I
/* size of a font *I
ff_magic;
ff_flags;
ff_hs;
ff_vs;
ff_baseline;
ff_dummy [ 26] ;
ff_fc[FNTSIZE];
ff_raster;
j* magic number *I
/* flags *I
/* hor spacing *I
I* ver spacing *I
/* baseline *I
/* padding *I
I* char defs *I
/* minirasters *I
struct fcdef I* font character definition *I
{
char
char
char
char
char
char
short
fc_hs;
fc_vs;
fc_ha;
fc_va;
fc_hi;
fc_vi;
fc_mr;
/* horiwntal size in bits *I
/* vertical size *I
I* horizontal adjust (signed) *I
I* vertical adjust (signed) *I
I* horizontal increment * I
/* vertical increment *I
/* relative mini-raster pointer *I
Each mini-raster is dealt with as 16-bit words; hence it must be
word-aligned, and consist of fc_hs raster lines each of which contains
an integral number of 16-bit data words. The actual position
of upper-left corner of miniraster is ( curx + fc_ha, cury + fc_va
) . Every word of mini-raster information is stored HIGH byte
first, a Ia mc68000. The low order bit of the first word is the leftmost
raster point. Bit-0 of the first word thus corresponds to the
upper- left corner of the character.
The actual bit pattern of a character is flush left in its mini-raster.
The bits to the right of the pattern (i.e. to the right of fc_hs ) and
before the short boundary must be 0. Normally, fc_va is negative,
thus implying that coordinate (0, 0) is upper left.
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