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freetype2/docs/formats.txt

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This file contains a list of various font formats. It gives the
reference document and whether it is supported in FreeType 2.
Table fields
------------
wrapper format
The format used to represent the font data. In the table below it
is used only if the font format differs. Possible values are
SFNT binary
PFB binary
PS a text header, followed by binary or text data
LZW compressed with either `gzip' or `compress'
BZ2 compressed with `bzip2'.
font format
How the font is to be accessed, possibly after converting the file
type and wrapper format into a generic form. Bitmap formats are
`BDF', `PCF', and one form of `WINFNT'; all others are vector
formats. `PS' indicates third-order, `TT' second-order Bézier
curves.
font type
Sub-formats of the font format. `SBIT' and `MACSBIT' are bitmap
formats, `MM' and `VAR' support optical axes. `CFF2' supports
optical axes also.
glyph access
If not specified, the glyph access is `standard' to the font
format. Values are `CID' for CID-keyed fonts, `SYNTHETIC' for
fonts that are modified versions of other fonts by means of a
transformation matrix, and `TYPE_0' for PS fonts which are to be
accessed in a tree-like structure.
FreeType driver
The module in the FreeType library which handles the specific font
format. A missing entry means that FreeType doesn't support the
font format (yet).
Notes
-----
The SFNT container format also provides `collections' (usually
having the file extension `.ttc' or `.otc'). A collection contains
multiple font faces that share some tables to avoid redundancy, thus
reducing the file size. In FreeType, elements of a collection can
be accessed with a proper face index.
Both the GX and the OpenType 1.8 variation fonts provide `named
instances'. FreeType maps them to face indices (they can also be
accessed with the standard MM interface).
Other font formats (not using the SFNT wrapper) also provide
multiple faces within one file; they are marked with an asterisk
(`*') in the table below.
FreeType can be configured to support Mac files (on older Mac OS
versions, a `file' is stored as a data and a resource fork, that is,
within two separate data chunks). If a file can't be opened as a
font, FreeType then checks whether it is a resource fork, trying to
extract the contained font data from either a `POST' or `sfnt'
resource.
Please send additions and/or corrections to wl@gnu.org or to the
FreeType developer's list at freetype-devel@nongnu.org (for
subscribers only). If you can provide a font example for a format
which isn't supported yet please send a mail too.
wrapper font font glyph FreeType reference
format format type access driver documents
-----------------------------------------------------------------------------
--- BDF --- --- bdf 5005.BDF_Spec.pdf, X11
SFNT PS TYPE_1 --- type1 Type 1 GX Font Format [7]
(for the Mac; not supported)
SFNT PS TYPE_1 CID cid 5180.sfnt.pdf (for the Mac) [3]
SFNT PS CFF --- cff OT spec, 5176.CFF.pdf
(`OTTO' format)
SFNT PS CFF CID cff OT spec, 5176.CFF.pdf
SFNT PS CFF SYNTHETIC --- OT spec, 5176.CFF.pdf
SFNT PS CFF2 --- cff OT spec 1.8
SFNT TT SBIT --- sfnt XFree86 (bitmaps only;
with `head' table)
SFNT TT MACSBIT --- sfnt OT spec (for the Mac;
bitmaps only; `bhed' table)
SFNT TT --- --- truetype OT spec (`normal' TT font)
SFNT TT VAR --- truetype GX spec (`?var' tables)
SFNT TT VAR --- truetype OT spec 1.8
(`?var' + `?VAR' tables)
WOFF --- --- --- cff, Compressed SFNT, ver. 1.0 [6]
truetype
WOFF2 --- --- --- cff, Compressed SFNT, ver. 2.0 [6]
truetype
--- PS TYPE_1 --- type1 T1_SPEC.pdf
(PFA, Type 1 font resource)
PFB PS TYPE_1 --- type1 T1_SPEC.pdf,
5040.Download_Fonts.pdf
(`normal' Type 1 font)
--- PS TYPE_1 CID cid PLRM.pdf (CID Font Type 0;
Type 9 font)
--- PS MM --- type1 5015.Type1_Supp.pdf
(Multiple Masters)
--- PS CFF --- cff 5176.CFF.pdf (`pure' CFF)
--- PS* CFF CID cff 5176.CFF.pdf (`pure' CFF)
--- PS CFF SYNTHETIC --- 5176.CFF.pdf (`pure' CFF)
--- PS CFF/MM --- cff old 5167.CFF.pdf (`pure' CFF)
[3]
--- PS* CFF/MM CID cff old 5167.CFF.pdf (`pure' CFF)
[3]
--- PS CFF/MM SYNTHETIC --- old 5167.CFF.pdf (`pure' CFF)
[3]
PS PS CFF --- --- PLRM.pdf (Type 2) [1]
PS PS* CFF CID --- PLRM.pdf (Type 2) [1]
PS PS CFF SYNTHETIC --- PLRM.pdf (Type 2) [1]
PS PS CFF/MM --- --- PLRM.pdf (Type 2) [1]
PS PS* CFF/MM CID --- PLRM.pdf (Type 2) [1]
PS PS CFF/MM SYNTHETIC --- PLRM.pdf (Type 2) [1]
--- PS --- TYPE_0 --- PLRM.pdf
--- PS TYPE_3 --- --- PLRM.pdf (never supported)
--- PS TYPE_3 CID --- PLRM.pdf (CID Font Type 1;
Type 10 font; never supported)
PS PS TYPE_14 --- --- PLRM.pdf (Chameleon font;
Type 14 font; never supported?)
--- PS TYPE_32 CID --- PLRM.pdf (CID Font Type 4;
Type 32 font; never supported?)
PS TT --- --- type42 5012.Type42_Spec.pdf
(Type 42 font)
PS TT --- CID --- PLRM.pdf (CID Font Type 2;
Type 11 font)
? ? CEF ? cff ?
--- PCF --- --- pcf X11 [4]
LZW PCF --- --- pcf X11 [4]
BZ2 PCF --- --- pcf X11 [4]
--- PFR* PFR0 --- pfr [2]
--- PFR PFR1 --- --- (undocumented, proprietary;
probably never supported)
--- WINFNT* --- --- winfonts Windows developer's notes [5]
--- WINFNT VECTOR --- --- Windows developer's notes [5]
[1] Support should be rather simple since this is identical to `CFF'
but in a PS wrapper.
[2] The official PFR specification is no longer available, but
archive.org has archived it:
https://web.archive.org/web/20091014062300/http://www.bitstream.com/font_rendering/products/truedoc/pfrspec.html
https://web.archive.org/web/20081115152605/http://www.bitstream.com/font_rendering/pdfs/pfrspec1.3.pdf
The syntax of the auxiliary data is not defined there, but is
partially defined in MHP 1.0.3 (also called ETSI TS 101812 V1.3.1)
section 7.4.
https://www.etsi.org/
https://webapp.etsi.org/workprogram/Report_WorkItem.asp?WKI_ID=18799
[3] Support is rudimentary currently; some tables or data are not
loaded yet.
[4] See
THE X WINDOW SYSTEM SERVER: X VERSION 11, RELEASE 5
Elias Israel, Erik Fortune, Digital Press, 1992
ISBN 1-55558-096-3
for a specification given in Appendix D on pgs. 436-450. However,
this information might be out of date; unfortunately, there is no
PCF specification available online, and this book is out of print.
George Williams deduced the font format from the X11 sources and
documented it for his FontForge font editor:
https://fontforge.github.io/pcf-format.html
[5] This is from MS Windows 3; see Microsoft's Knowledge Base article
at
https://support.microsoft.com/kb/65123
[6] Supported font formats are TrueType and OpenType fonts as
defined in the OpenType specification 1.6 and newer.
[7] `The Type 1 GX Font Format' (dated 1995-09-27) was distributed in
Apple Developer CD-ROM in those days. The content of `TYP1' table
is a PostScript Type 1 font without the eexec encryption. Current
versions of FreeType don't not support this format, but FontForge
can load it.
------------------------------------------------------------------------
Copyright (C) 2004-2024 by
David Turner, Robert Wilhelm, and Werner Lemberg.
This file is part of the FreeType project, and may only be used,
modified, and distributed under the terms of the FreeType project
license, LICENSE.TXT. By continuing to use, modify, or distribute this
file you indicate that you have read the license and understand and
accept it fully.
--- end of formats.txt ---
Local Variables:
coding: utf-8
End:
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