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<TITLE>Spline Font Database File Format</TITLE>
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<H1 ALIGN=Center>
Spline Font Database
</H1>
<P>
PfaEdit's <A HREF="sfd.html">sfd</A> files are ASCII files (so they can be
copied easily across the internet). They contain a full description of your
font.
<P>
They are vaguely modeled on bdf files. The first few lines contain general
font properties, then there's a section for each character, then a section
for each bitmap font.
<P>
Here is an example of what the first few lines look like:
<BLOCKQUOTE>
<PRE>SplineFontDB: 1.0
FontName: Ambrosia
FullName: Ambrosia
FamilyName: Ambrosia
Weight: Medium
Copyright: Copyright (C) 1995-2000 by George Williams
Version: 001.000
ItalicAngle: 0
UnderlinePosition: -133
UnderlineWidth: 20
Ascent: 800
Descent: 200
DisplaySize: 24
AntiAlias: 1
XUID: 3 18 21
Encoding: -1
</PRE>
</BLOCKQUOTE>
<P>
The first line just identifies the file as an sfd file. The next few lines
give the various different names that postscript allows fonts to have. Then
some fairly self-explanatory items. The thing that probably needs explanation
is the encoding, this is an enum some of whose values are:
<UL>
<LI>
-1 -- custom encoding
<LI>
0 -- ISO 8859-1
<LI>
1 -- ISO 8859-2
<LI>
... (there is no ISO 8859-12 so)
<LI>
11 -- ISO 8859-13
<LI>
...
<LI>
16 -- Windows
<LI>
17 -- Macintosh
<LI>
20 -- Adobe Standard
<LI>
23 -- JIS 208
<LI>
28 -- Unicode
</UL>
<P>
We also support user defined encodings, these are listed not as a number
but as a string that names the encoding. CID fonts have no encodings, instead
they have
<BLOCKQUOTE>
<PRE>Registry: Adobe
Ordering: japan1
Supplement: 4
</PRE>
</BLOCKQUOTE>
<P>
Some fonts will have some TrueType information in them too (look at the
<A HREF="http://www.microsoft.com/typography/tt/tt.htm">truetype spec</A>
for the meanings of these).
<BLOCKQUOTE>
<PRE>FSType: 4
PFMFamily: 17
TTFWeight: 400
TTFWidth: 5
Panose: 2 0 5 3 0 0 0 0 0 0
</PRE>
</BLOCKQUOTE>
<P>
The <CODE>LangName</CODE> entries represent the TrueType names table the
number represents the language and is followed by a list of strings encoded
in UTF-7. The first string corresponds to ID=0 (Copyright), the second to
ID=1 (Family), ... trailing empty strings will be omitted. In the American
English language (1033) section, if one of these names exactly matches the
equivalent postscript item then that name will be omitted (this makes it
easier to handle updates, users only have to change the copyright in one
place)
<BLOCKQUOTE>
<PRE>
LangName: 1033 "" "" "Regular" "GWW:Caliban Regular: Version 1.0" "" "Version 1.0"
LangName: 1032 "" "" "+A5oDsQ09A78DvQ05A7oDrAAA"
</PRE>
</BLOCKQUOTE>
<P>
Then for non-CID fonts:
<BLOCKQUOTE>
<PRE>BeginChars: 285 253
</PRE>
</BLOCKQUOTE>
<P>
This means that the font has room for 285 characters and that there are a
total of 253 defined (usually control characters are not defined). A character
looks like:
<BLOCKQUOTE>
<PRE>StartChar: exclam
Encoding: 33 33
Width: 258
Flags:
HStem: 736 13 -14 88
VStem: 71 84
Fore
195 742 m 0
195 738 193 736 189 736 c 0
175 736 155 743 155 682 c 0
155 661 130 249 130 131 c 0
130 100 96 99 96 131 c 0
96 149 71 662 71 682 c 0
71 731 51 736 37 736 c 0
33 736 31 738 31 742 c 0
31 748 36 747 38 749 c 1
188 749 l 1
190 747 195 748 195 742 c 0
80 32 m 0
81 53 95 75 116 74 c 0
137 73 150 53 150 32 c 0
150 10 137 -14 115 -14 c 0
93 -14 79 10 80 32 c 0
EndSplineSet
EndChar
</PRE>
</BLOCKQUOTE>
<P>
The first line names the character, the next line gives the encoding, first
in the current font, then in unicode. Then the width. Then horizontal and
vertical stem hints (set of several two number pairs, the first number in
the pair is the location of the stem, the next number is the width of the
stem). The entry <CODE>Fore</CODE> starts the foreground splines, they are
encoded as postscript commands with moveto abbreviated to m, curveto to c
and lineto to l (lower case el). The digit after after the letter indicates
whether the point is curve (0), corner (1) or tangent (2). A set of splines
in the background is similar, it will be introduced by a <CODE>Back</CODE>
entry.
<BLOCKQUOTE>
<PRE>StartChar: semicolon
Encoding: 59 59
Width: 264
Flags:
HStem:
VStem:
Ref: 44 N 1 0 0 1 0 0
Ref: 46 N 1 0 0 1 0 414
EndChar
</PRE>
</BLOCKQUOTE>
<P>
A character need not contain any splines. Here is one with just references
to other characters (a semi-colon is drawn here by drawing a comma and stacking
a period on top of it). The first number is the local encoding of the character
being refered to, the N says the reference is not selected, the remaining
6 numbers are a postscript transformation matrix, the one for comma (44)
is the identity matrix, while the one for period (46) just translates it
vertically 414 units. A background image is store in the following horrible
format:
<BLOCKQUOTE>
<PRE>StartChar: A
...
Image: 167 301 0 21 2 1 23 753 2.53892 2.53892
J:N0SYd"0-qu?]szzz!!#7`s7cQozzz!!!!(s8Viozzzz"98E!zzzz!!3-"rVuouzzz!!!'"
s8N'!zzz!!!!$s8W,7zzzz"98E$huE`WzJ+s!Dz!"],0s6p!g!!!!"s8W-!n,NFg!!!Q0s8Vio
z5QCc`s82is!!!!`s8W,gz!WW3"s8W&uzJ,fQKp](9o!!iQ(s8W-!z!<<*!s7cQo!!",@s8W-!
...
EndImage
EndChar
</PRE>
</BLOCKQUOTE>
<P>
Where the numbers on the image line mean respectively: width (of image in
pixels), height, image type (0=>mono, 1=>indexed, 2=>true), bytes
per line, number of color entries in the color table, the index in the color
table of the transparent color (or for true color images the transparent
color itself), the x and y coordinates of the upper left corner of the image,
the x and y scale factors to convert image pixels into character units. Then
follows a bunch of binary data encoded using Adobe's Encode85 filter. These
data contain all the colors in the color table followed by a dump of the
image pixel data.
<P>
There may be a Grid entry near the top of the font, this specifies the splines
to be drawn in the grid layer for the font, and looks like any other splineset:
<BLOCKQUOTE>
<PRE>Grid
678 -168 m 5
-40 -168 l 5
-678 729 m 1
1452 729 l 1
-678 525 m 1
1452 525 l 1
EndSplineSet
</PRE>
</BLOCKQUOTE>
<P>
After all the outline characters have been described there is an EndChars
entry and then follow any bitmap fonts:
<BLOCKQUOTE>
<PRE>EndChars
BitmapFont: 12 285 10 2
BDFChar: 32 3 0 0 0 0
z
BDFChar: 33 3 0 1 0 9
^d(.M5X7S"!'gMa
</PRE>
</BLOCKQUOTE>
<P>
The bitmap font line contains the following numbers: the pixelsize of the
font, the number of potential characters in the font, the ascent and the
descent of the font. This is followed by a list of bitmap characters, the
bitmap character line contains the following numbers: the encoding (local),
the width, the minimum x value, the minimum y value, the maximum x value
and the maximum y value. This is followed by another set of binary data encoded
as above there will be (ymax-ymin+1)* ((xmax-xmin+8)/8) (unencoded) bytes,
there is no color table here (the high order bit comes first in the image,
set bits should be colored black, clear bits transparent).
<P>
A bitmap font is ended by:
<BLOCKQUOTE>
<PRE>EndBitmapFont
BitmapFont: 17 285 14 3
BDFChar: 0 17 0 0 0 0
z
...
EndBitmapFont
EndSplineFont
</PRE>
</BLOCKQUOTE>
<P>
If the font has been read in from a type1 postscript font, then there may
also be entries for a subroutine list. These are type1 strings (similar to
origtype1 in the character entry). A subroutine list starts with at
<CODE>BeginSubrs:</CODE> keyword which is followed by the number of subroutines.
Then a new line, on which the length of each subroutine will appear (this
may take more than one line if there are lots of subroutines). Then (on the
next line) an encode85ed string containing all the bytes in all the subroutines
(the lengths above provide enough information to map a byte to the appropriate
subroutine). Finally a keyword <CODE>EndSubrs</CODE>.
<P>
A font may also have some private data (either from reading at type1 font,
or because the user created it), this is mostly hinting information. Private
data begins with the keyword <CODE>BeginPrivate:</CODE> and is followed by
the count of private items. Each private item starts on a new line, it begins
with the name of the entry, is followed by a number (containing the length
of the entry's value) and then then entry's value. The value may contain
new lines. There will be a newline after the value. The private list is ended
by an <CODE>EndPrivate</CODE> keyword.
<P>
A CID font is saved slighlty differently. It begins with the normal font
header which contains the information in the top level CID font dictionary.
As mentioned above this will include special keys that specify the CID charset
(registry, ordering, supplement). It will also include:
<BLOCKQUOTE>
<PRE>CIDVersion: 2.0
BeginSubFonts: 5 8318
</PRE>
</BLOCKQUOTE>
<P>
The <CODE>CIDVersion</CODE> is self-explanitory. The
<CODE>BeginSubFonts</CODE> line says that there are 5 subfonts the largest
of which contains slots for 8318 characters (again some of these may not
be defined). This will be followed by a list of the subfonts (dumped out
just like normal fonts) and their characters. Only the top level font will
contain any bitmap characters.
<H2>
Autosave Format
</H2>
<P>
<A HREF="errrecovery.html">Error recovery</A> files are saved in
~/.PfaEdit/autosave, they have quite random looking names and end in .asfd.
They look very similar to .sfd files above.
<P>
If an asfd file starts with a line:
<BLOCKQUOTE>
<PRE>Base: /home/gww/myfonts/pfaedit/Ambrosia.sfd
</PRE>
</BLOCKQUOTE>
<P>
Then it is assumed to be a list of changes applied to that file (which may
be an sfd file or a font file). If it does not start with a
"<CODE>Base:</CODE>" line then it is assumed to be a new font. The next line
contains the encoding, as above. The next line is a <CODE>BeginChars</CODE>
line. The number given on the line is not the number of characters in the
file, but is the maximum number that could appear in the font. Then follows
a list of all changed characters in the font (in the format described above).
<P>
Bitmaps are not preserved. Grid changes are not preserved.
<P>
<P ALIGN=Center>
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