[1mBitmap Distribution Format[0m
[1mVersion 2.1[0m
X Consortium Standard
X Version 11, Release 6.4
Copyright 1984, 1987, 1988 Adobe Systems, Inc.
Permission to use, copy, modify, and distribute this soft-
ware and its documentation for any purpose and without fee
is hereby granted, provided that the above copyright notice
appear in all copies and that both that copyright notice and
this permission notice appear in supporting documentation.
The Bitmap Distribution Format (BDF), Version 2.1, is an X
Consortium standard for font interchange, intended to be
easily understood by both humans and computers.
[1mFile Format[0m
Character bitmap information will be distributed in an
USASCII-encoded, human-readable form. Each file is encoded
in the printable characters (octal 40 through 176) of
USASCII plus carriage return and linefeed. Each file con-
sists of a sequence of variable-length lines. Each line is
terminated either by a carriage return (octal 015) and line-
feed (octal 012) or by just a linefeed.
The information about a particular family and face at one
size and orientation will be contained in one file. The
file begins with information pertaining to the face as a
whole, followed by the information and bitmaps for the indi-
vidual characters.
A font bitmap description file has the following general
form, where each item is contained on a separate line of
text in the file. Tokens on a line are separated by spaces.
Keywords are in upper case, and must appear in upper case in
the file.
1. The word STARTFONT followed by a version number indi-
cating the exact file format used. The version
described here is 2.1.
-2-
2. Lines beginning with the word COMMENT may appear any-
where between the STARTFONT line and the ENDFONT line.
These lines are ignored by font compilers.
3. The word FONT followed by either the XLFD font name (as
specified in part III) or some private font name. Cre-
ators of private font name syntaxes are encouraged to
register unique font name prefixes with the X Consor-
tium to prevent naming conflicts. Note that the name
continues all the way to the end of the line and may
contain spaces.
4. The word SIZE followed by the [4mpoint[24m [4msize[24m of the charac-
ters, the [4mx[24m [4mresolution[24m, and the [4my[24m [4mresolution[24m of the
device for which these characters were intended.
5. The word FONTBOUNDINGBOX followed by the [4mwidth[24m [4min[24m [4mx[24m,
[4mheight[24m [4min[24m [4my[24m, and the x and y displacement of the lower
left corner from the [4morigin[24m. (See the examples in the
next section.)
6. Optionally, the word STARTPROPERTIES followed by the
number of properties ([4mp[24m) that follow.
7. Then come [4mp[24m lines consisting of a word for the [4mproperty[0m
[4mname[24m followed by either an integer or string surrounded
by double-quote (octal 042). Internal double-quote
characters are indicated by using two in a row.
Properties named FONT_ASCENT, FONT_DESCENT, and
DEFAULT_CHAR should be provided to define the logical
font-ascent and font-descent and the default-char for
the font. These properties will be removed from the
actual font properties in the binary form produced by a
compiler. If these properties are not provided, a com-
piler may reject the font or may compute (arbitrary)
values for these properties.
8. The property section, if it exists, is terminated by
ENDPROPERTIES.
9. The word CHARS followed by the number of character seg-
ments ([4mc[24m) that follow.
10. Then come [4mc[24m character segments of the form:
a. The word STARTCHAR followed by up to 14 characters
(no blanks) of descriptive [4mname[24m of the glyph.
b. The word ENCODING followed by one of the following
forms:
i. <n> - the glyph index, that is, a positive
integer representing the character code used
-3-
to access the glyph in X requests, as defined
by the encoded character set given by the
CHARSET_REGISTRY-CHARSET_ENCODING font prop-
erties for XLFD conforming fonts. If these
XLFD font properties are not defined, the
encoding scheme is font-dependent.
ii. -1 <n> - equivalent to form above. This syn-
tax is provided for backward compatibility
with previous versions of this specification
and is not recommended for use with new
fonts.
iii. -1 - an unencoded glyph. Some font compilers
may discard unencoded glyphs, but, in gen-
eral, the glyph names may be used by font
compilers and X servers to implement dynamic
mapping of glyph repertoires to character
encodings as seen through the X protocol.
c. The word SWIDTH followed by the [4mscalable[24m [4mwidth[24m in
x and y of character. Scalable widths are in
units of 1/1000th of the size of the character.
If the size of the character is [4mp[24m points, the
width information must be scaled by [4mp[24m/1000 to get
the width of the character in printer's points.
This width information should be considered as a
vector indicating the position of the next charac-
ter's origin relative to the origin of this char-
acter. To convert the scalable width to the width
in device pixels, multiply SWIDTH times [4mp[24m/1000
times [4mr[24m/72, where [4mr[24m is the device resolution in
pixels per inch. The result is a real number giv-
ing the ideal print width in device pixels. The
actual device width must of course be an integral
number of device pixels and is given in the next
entry. The SWIDTH y value should always be zero
for a standard X font.
d. The word DWIDTH followed by the width in x and y
of the character in device units. Like the
SWIDTH, this width information is a vector indi-
cating the position of the next character's origin
relative to the origin of this character. Note
that the DWIDTH of a given ``hand-tuned'' WYSIWYG
glyph may deviate slightly from its ideal device-
independent width given by SWIDTH in order to
improve its typographic characteristics on a dis-
play. The DWIDTH y value should always be zero
for a standard X font.
e. The word BBX followed by the width in x ([4mBBw[24m),
[4mheight[24m in y ([4mBBh[24m), and x and y displacement ([4mBBox[24m,
[4mBBoy[24m) of the lower left corner from the [4morigin[24m of
-4-
the character.
f. The optional word ATTRIBUTES followed by the
attributes as 4 [4mhex-encoded[24m characters. The
interpretation of these attributes is undefined in
this document.
g. The word BITMAP.
h. [4mh[24m lines of [4mhex-encoded[24m bitmap, padded on the right
with zeros to the nearest byte (that is, multiple
of 8).
i. The word ENDCHAR.
11. The file is terminated with the word ENDFONT.
[1mMetric Information[0m
Figures 1 and 2 best illustrate the bitmap format and char-
acter metric information.
-5-
BBw = 9, BBh = 22, BBox = -2, BBoy = -6
DWIDTH = 8 0
SWIDTH = 355 0
``+'' = character origin and width
Figure 1: An example of a descender
-6-
BBh = 6, BBw = 4, BBox = +2, BBoy = +12
DWIDTH = 5 0
SWIDTH = 223 0
Figure 2: An example with the origin outside the bounding box
-7-
[1mAn Example File[0m
The following is an abbreviated example of a bitmap file
containing the specification of two characters (the j and
quoteright in figures 1 and 2).
STARTFONT 2.1 COMMENT This is a sample font in 2.1 format.
FONT -Adobe-Helvetica-Bold-R-Nor-
mal--24-240-75-75-P-65-ISO8859-1 SIZE 24 75 75 FONTBOUNDING-
BOX 9 24 -2 -6 STARTPROPERTIES 19 FOUNDRY "Adobe" FAMILY
"Helvetica" WEIGHT_NAME "Bold" SLANT "R" SETWIDTH_NAME "Nor-
mal" ADD_STYLE_NAME "" PIXEL_SIZE 24 POINT_SIZE 240 RESOLU-
TION_X 75 RESOLUTION_Y 75 SPACING "P" AVERAGE_WIDTH 65
CHARSET_REGISTRY "ISO8859" CHARSET_ENCODING "1" MIN_SPACE 4
FONT_ASCENT 21 FONT_DESCENT 7 COPYRIGHT "Copyright (c) 1987
Adobe Systems, Inc." NOTICE "Helvetica is a registered
trademark of Linotype Inc." ENDPROPERTIES CHARS 2 STARTCHAR
j ENCODING 106 SWIDTH 355 0 DWIDTH 8 0 BBX 9 22 -2 -6 BITMAP
0380 0380 0380 0380 0000 0700 0700 0700 0700 0E00 0E00 0E00
0E00 0E00 1C00 1C00 1C00 1C00 3C00 7800 F000 E000 ENDCHAR
STARTCHAR quoteright ENCODING 39 SWIDTH 223 0 DWIDTH 5 0 BBX
4 6 2 12 ATTRIBUTES 01C0 BITMAP 70 70 70 60 E0 C0 ENDCHAR
ENDFONT
