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freetype/docs/CHANGES
Werner Lemberg 6e188b419d formatting
2002-04-17 22:42:13 +00:00

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LATEST CHANGES BETWEEN 2.1.0 and 2.0.9
I. IMPORTANT BUG FIXES
- The TrueType bytecode interpreter has been fixed to produce
_exactly_ the same output as FreeType 1.x. Previous differences
were due to slightly distinct fixed-point computation routines
used to perform dot products and vector length measurements.
It seems that native TrueType hinting is _extremely_ sensitive
to rounding errors. The required vector computation routines have
been optimized and placed within the "ttinterp.c" file.
- Fixed the parsing of accelerator tables in the PCF font driver.
- Fixed the Type1 glyph loader routine used to compute the font's
maximum advance width.
II. NEW FEATURES
- The `configure' script used on Unix systems has been modified to
check that GNU Make is being used to build the library. Otherwise,
it will display a message proposing to use the GNUMAKE environment
variable to name it.
The Unix-specific file README.UNX has been modified accordingly.
III. MISCELLANEOUS
- The FreeType License in `docs/FTL.txt' has been updated to include
a proposed preferred disclaimer. If you are using FreeType in your
products, you are encouraged (but not mandated) to use the following
text in your documentation:
"""
Portions of this software are copyright © 1996-2002 The FreeType
Project (www.freetype.org). All rights reserved.
"""
- The default size of the render pool has been reduced to 16kByte.
This shouldn't result in any noticeable performance penalty, unless
you are using the engine as-is to render very large and complex
glyphs.
- The FreeType 2 redesign has begun. More information can be found
at this URL:
http://www.freetype.org/freetype2/redesign.html
The following internal changes have been performed within the sources
of this release:
- Many internal types have been renamed to increase consistency.
The following should be true, except for public types:
* All structure types have a name ending in "Rec" (short for
`record').
* A pointer-to-structure type has the same name as the
structure, _without_ the "Rec" suffix.
Example:
typedef struct FooRec_
{
...
} FooRec, *Foo;
- Many internal macros have been renamed to increase consistency.
The following should be true:
* All macros have a name beginning with "FT_". This required
a few changes like
ALLOC => FT_ALLOC
FREE => FT_FREE
REALLOC => FT_REALLOC
* All macros are completely UPPERCASE. This required a few
changes like:
READ_Short => FT_READ_SHORT
NEXT_Short => FT_NEXT_SHORT
GET_ULongLE => FT_GET_ULONG_LE
MEM_Set => FT_MEM_SET
MEM_Copy => FT_MEM_COPY
etc.
* Whenever possible, all macro names follow the
FT_<OBJECT>_<METHOD> pattern. For example
ACCESS_Frame => FT_FRAME_ENTER
FORGET_Frame => FT_FRAME_EXIT
EXTRACT_Frame => FT_FRAME_EXTRACT
RELEASE_Frame => FT_FRAME_RELEASE
FILE_Pos => FT_STREAM_POS
FILE_Seek => FT_STREAM_SEEK
FILE_Read => FT_STREAM_READ
FILE_ReadAt => FT_STREAM_READ_AT
READ_Fields => FT_STREAM_READ_FIELDS
- Many internal functions have been renamed to follow the
FT_<Object>_<Method> pattern. For example:
FT_Seek_Stream => FT_Stream_Seek
FT_Read_Stream_At => FT_Stream_ReadAt
FT_Done_Stream => FT_Stream_Close
FT_New_Stream => FT_Stream_Open
FT_New_Memory_Stream => FT_Stream_OpenMemory
FT_Extract_Frame => FT_Stream_ExtractFrame
Note that method names do not contain "_".
- The FT_ALLOC_ARRAY and FT_REALLOC_ARRAY have been replaced
with FT_NEW_ARRAY and FT_RENEW_ARRAY which do not take a type
as the fourth argument. Instead, the array element type size
is computed automatically from the type of the target pointer
used.
- A new object class, FT_CMap, has been introduced. These
internal objects are used to model character maps. This eases
the support of additional charmap types within the engine.
- A new configuration file named "ftstdlib.h" has been added
to `include/freetype/config'. It is used to define aliases
for _every_ routine of the ISO C library that the font engine
uses. Each aliases has a "ft_" prefix (e.g. "ft_strlen" is an
alias for "strlen").
This is used to ease the porting of FreeType 2 to exotic runtime
environments where the ISO C Library isn't available (e.g.
XFree86 extension modules).
More details are available in the "ChangeLog" file.
============================================================================
LATEST CHANGES BETWEEN 2.0.9 and 2.0.8
I. IMPORTANT BUG FIXES
- Certain fonts like "foxjump.ttf" contain broken name tables with
invalid entries and wild offsets. This caused FreeType to crash when
trying to load them.
The SFNT `name' table loader has been fixed to be able to support
these strange fonts.
Moreover, the code in charge of processing this table has been changed
to always favour Windows-formatted entries over other ones. Hence, a
font that works on Windows but not on the Mac will load cleanly in
FreeType and report accurate values for Family & PostScript names.
- The CID font driver has been fixed. It unfortunately returned a
Postscript Font name with a leading slash, as in
"/MunhwaGothic-Regular".
- FreeType 2 should now compile fine on AIX 4.3.3 as a shared library.
- A bug in the Postscript hinter has been found and fixed, removing
un-even stem widths at small pixel sizes (like 14-17).
This improves the quality of a certain number of Postscript fonts.
II. NEW FEATURES
- A new function named `FT_Library_Version' has been added to return
the current library's major, minor, and patch version numbers. This
is important since the macros FREETYPE_MAJOR, FREETYPE_MINOR, and
FREETYPE_PATCH cannot be used when the library is dynamically linked
by a program.
- Two new APIs have been added: `FT_Get_First_Char' and
`FT_Get_Next_Char'.
Together, these can be used to iterate efficiently over the currently
selected charmap of a given face. Read the API reference for more
details.
III. MISCELLANEOUS
- The FreeType sources are under heavy internal re-factoring. As a
consequence, we have created a branch named "STABLE" on the CVS to
hold all future releases/fixes in the 2.0.x family.
The HEAD branch now contains the re-factored sources and shouldn't be
used for testing or packaging new releases. In case you would like
to access the 2.0.9 sources from our CVS repository, use the tag
`VER-2-0-9'.
============================================================================
LATEST CHANGES BETWEEN 2.0.8 and 2.0.7
I. IMPORTANT BUG FIXES
- There was a small but nasty bug in "freetype-config.in" which
caused the "freetype-config" script to fail on Unix.
This didn't prevent the installation of the library or even
its execution, but caused problems when trying to compile many
Unix packages that depend on it.
- Some TrueType or OpenType fonts embedded in PDF documents do
not have a 'cmap', 'post' and 'name' as is required by the
specification. FreeType no longer refuses to load such fonts.
- various fixes to the PCF font driver
============================================================================
LATEST CHANGES BETWEEN 2.0.7 and 2.0.6
I. IMPORTANT BUG FIXES
- Fixed two bugs in the Type 1 font driver. The first one resulted in a
memory leak in subtle cases. The other one caused FreeType to crash
when trying to load ".gsf" files (Ghostscript so-called Postscript
fonts).
(This made _many_ KDE applications crash on certain systems. FreeType
_is_ becoming a critical system component on Linux :-)
- Fixed a memory leak in the CFF font driver.
- Fixed a memory leak in the PCF font driver.
- Fixed the Visual C++ project file "builds/win32/visualc/freetype.dsp"
since it didn't include the Postscript hinter component, causing
errors at build time.
- Fixed a small rendering bug in the anti-aliased renderer that only
occurred when trying to draw thin (less than 1 pixel) strokes.
- Fixed "builds/unix/freetype2.a4" which is used to generate a valid
"freetype2.m4" for use with autoconf.
- Fixed the OpenVMS Makefiles.
II. MISCELLANEOUS
- Added "configure" and "install" scripts to the top-level directory.
A GNU-style installation is thus now easily possible with
./configure <options>
make
make install
============================================================================
LATEST CHANGES BETWEEN 2.0.6 and 2.0.5
I. IMPORTANT BUG FIXES
- It wasn't possible to load embedded bitmaps when the auto-hinter was
used. This is now fixed.
- The TrueType font driver didn't load some composites properly (the
sub-glyphs were slightly shifted, and this was only noticeable when
using monochrome rendering).
- Various fixes to the auto-hinter. They merely improve the output of
sans-serif fonts. Note that there are still problems with serifed
fonts and composites (accented characters).
- All scalable font drivers erroneously returned un-fitted glyph
advances when hinting was requested. This created problems for a
number of layout applications. This is a very old bug that got
undetected mainly because most test/demo program perform rounding
explicitly or implicitly (through the cache).
- FT_Glyph_To_Bitmap() did erroneously modify the source glyph in
certain cases.
- "glnames.py" still contained a bug that made FreeType return invalid
names for certain glyphs.
- The library crashed when loading certain Type 1 fonts like "sadn.pfb"
("Stalingrad Normal"), which appear to contain pathetic font info
dictionaries.
- The TrueType glyph loader is now much more paranoid and checks everything
when loading a given glyph image. This was necessary to avoid
problems (crashes and/or memory overwrites) with broken fonts that
came from a really buggy automatic font converter.
II. IMPORTANT UPDATES AND NEW FEATURES
- Important updates to the Mac-specific parts of the library.
- The caching sub-system has been completely re-designed, and its API
has evolved (the old one is still supported for backwards
compatibility).
The documentation for it is not yet completed, sorry. For now, you
are encouraged to continue using the old API. However, the ftview
demo program in the ft2demos package has already been updated to use
the new caching functions.
- A new charmap cache is provided too. See FTC_CMapCache(). This is
useful to perform character code -> glyph index translations quickly,
without the need for an opened FT_Face.
- A NEW POSTSCRIPT HINTER module has been added to support native hints
in the following formats: PostScript Type 1, PostScript CID, and
CFF/CEF.
Please test! Note that the auto-hinter produces better results for a
number of badly-hinted fonts (mostly auto-generated ones) though.
- A memory debugger is now part of the standard FreeType sources. To
enable it, define FT_DEBUG_MEMORY in <freetype/config/ftoption.h>, and
recompile the library.
Additionally, define the _environment_ variable FT_DEBUG_MEMORY and
run any program using FreeType. When the library is exited, a summary
of memory footprints and possible leaks will be displayed.
This works transparently with _any_ program that uses FreeType.
However, you will need a lot of memory to use this (allocated blocks
are never released to the heap to detect double deletes easily).
III. MISCELLANEOUS
- We are aware of subtle differences between the output of FreeType
versions 1 and 2 when it comes to monochrome TrueType-hinted glyphs.
These are most probably due to small differences in the monochrome
rasterizers and will be worked out in an upcoming release.
- We have decided to fork the sources in a "stable" branch, and an
"unstable" one, since FreeType is becoming a critical component of
many Unix systems.
The next bug-fix releases of the library will be named 2.0.7, 2.0.8,
etc., while the "2.1" branch will contain a version of the sources
where we will start major reworking of the library's internals, in
order to produce FreeType 2.2.0 (or even 3.0) in a more distant
future.
We also hope that this scheme will allow much more frequent releases
than in the past.
============================================================================
LATEST CHANGES BETWEEN 2.0.5 and 2.0.4
NOTE THAT 2.0.5 DOES NOT CONTAIN THE POSTSCRIPT HINTER. THIS MODULE WILL
BE PART OF THE NEXT RELEASE (EITHER 2.0.6 or 2.1)
- Fixed a bug that made certain glyphs, like "Cacute", "cacute" and
"lslash" unavailable from Unicode charmaps of Postscript fonts. This
prevented the correct display of Polish text, for example.
- The kerning table of Type 1 fonts was loaded by FreeType, when its AFM
file was attached to its face, but the FT_FACE_FLAG_HAS_KERNING bit
flags was not set correctly, preventing FT_Get_Kerning to return
meaningful values.
- Improved SFNT (TrueType & OpenType) charmap support. Slightly better
performance, as well as support for the new formats defined by the
OpenType 1.3 specification (8, 10, and 12)
- Fixed a serious typo in "src/base/ftcalc.c" which caused invalid
computations in certain rare cases, producing ugly artefacts.
- The size of the EM square is computed with a more accurate algorithm
for Postscript fonts. The old one caused slight errors with embedded
fonts found in PDF documents.
- Fixed a bug in the cache manager that prevented normal LRU behaviour
within the cache manager, causing unnecessary reloads (for FT_Face and
FT_Size objects only).
- Added a new function named "FT_Get_Name_Index" to retrieve the glyph
index of a given glyph name, when found in a face.
- Added a new function named "FT_Get_Postscript_Name" to retrieve the
"unique" Postscript font name of a given face.
- Added a new public header size named FT_SIZES_H (or
<freetype/ftsizes.h>) providing new FT_Size-management functions:
FT_New_Size, FT_Activate_Size, FT_Done_Size.
- Fixed a reallocation bug that generated a dangling pointer (and possibly
memory leaks) with Postscript fonts (in src/psaux/psobjs.c).
- Many fixes for 16-bit correctness.
- Removed many pedantic compiler warnings from the sources.
- Added an Amiga build directory in "builds/amiga".
============================================================================
LATEST CHANGES BETWEEN 2.0.4 and 2.0.3
- Fixed a rather annoying bug that was introduced in 2.0.3. Namely, the
font transformation set through FT_Set_Transform was applied twice to
auto-hinted glyphs, resulting in incorrectly rotated text output.
- Fixed _many_ compiler warnings. FT2 should now compile cleanly with
Visual C++'s most pedantic warning level (/W4). It already compiled
fine with GCC and a few other compilers.
- Fixed a bug that prevented the linear advance width of composite
TrueType glyphs to be correctly returned.
- Fixed the Visual C++ project files located in "builds/win32/visualc"
(previous versions used older names of the library).
- Many 32-bit constants have an "L" appended to their value, in order
to improve the 16-bitness of the code. Someone is actually trying to
use FT2 on an Atari ST machine!
- Updated the "builds/detect.mk" file in order to automatically build
FT2 on AIX systems. AIX uses "/usr/sbin/init" instead of "/sbin/init"
and wasn't previously detected as a Unix platform by the FreeType build
system.
- Updated the Unix-specific portions of the build system (new libtool
version, etc.).
- The SFNT kerning lodaer now ensures that the table is sorted (since some
problem fonts do not meet this requirement).
============================================================================
LATEST CHANGES BETWEEN 2.0.3 and 2.0.2
I. CHANGES TO THE MODULES / FONT DRIVERS
- THE AUTO-HINTER HAS BEEN SLIGHTLY IMPROVED, in order to fix several
annoying artefacts, mainly:
- Blue zone alignement of horizontal stems wasn't performed
correctly, resulting in artefacts like the "d" being placed one
pixel below the "b" in some fonts like Time New Roman.
- Overshoot thresholding wasn't performed correctly, creating
unpleasant artefacts at large character pixel sizes.
- Composite glyph loading has been simplified. This gets rid
of various artefacts where the components of a composite glyphs
were not correctly spaced.
These are the last changes to the current auto-hinting module. A new
hinting sub-system is currently in the work in order to support native
hints in Type 1 / CFF / OpenType fonts, as well as globally improve
rendering.
- The PCF driver has been fixed. It reported invalid glyph dimensions
for the fonts available on Solaris.
- The Type 1, CID and CFF drivers have been modified to fix the
computation of the EM size.
- The Type 1 driver has been fixed to avoid a dangerous bug that
crashed the library with non-conforming fonts (i.e. ones that do not
place the .notdef glyph at position 0).
- The TrueType driver had a rather subtle bug (dangling pointer when
loading composite glyphs) that could crash the library in rare
occasions!
II. HIGH-LEVEL API CHANGES
- The error code enumeration values have been changed. An error value
is decomposed in a generic error code, and a module number. see
<freetype/fterrors.h> for details.
- A new public header file has been introduced, named FT_TRIGONOMETRY_H
(include/freetype/fttrig.h), providing trigonometric functions to
compute sines, cosines, arctangents, etc. with 16.16 fixed precision.
The implementation is based on the CORDIC algorithm and is very fast
while being sufficiently accurate.
III. INTERNALS
- Added BeOS-specific files in the old build sub-system. Note that
no changes were required to compile the library with Jam.
- The configuration is now capable of automatically detecting 64-bit
integers on a set of predefined compilers (GCC, Visual C++, Borland
C++) and will use them by default. This provides a small performance
boost.
- A small memory leak that happened when opening 0-sized files (duh!)
have been fixed.
- Fixed bezier stack depth bug in the routines provided by the
FT_BBOX_H header file. Also fixed similar bugs in the rasterizers.
- The outline bounding box code has been rewritten to use direct
computations, instead of bezier sub-division, to compute the exact
bounding box of glyphs. This is slightly slower but more accurate.
- The build system has been improved and fixed, mainly to support "make"
on Windows 2000 correctly, avoid problems with "make distclean" on non
Unix systems, etc.
- Hexadecimal constants have been suffixed with "U" to avoid problems
with certain compilers on 64-bit platforms.
- A new directory named "src/tools" has been created. It contains
Python scripts and simple unit test programs used to develop the
library.
- The DocMaker tool has been moved from "docs" to "src/tools" and
has been updated with the following:
- Now accepts the "--title=XXXX" or "-t XXXX" option from the
command line to set the project's name in the generated API
reference.
- Now accepts the "--output=DIR" or "-o DIR" option from the
command line to set the output directory for all generated HTML
files.
- Now accepts the "--prefix=XXXX" or "-p XXX" option from the
command line to set the file prefix to use for all generated HTML
files.
- Now generates the current time/data on each generated page
in order to distinguish between versions.
DocMaker can be used with other projects now, not only FT2 (e.g. MLib,
FTLayout, etc.).
===========================================================================
LATEST CHANGES BETWEEN 2.0.2 and 2.0.1
I. CHANGES TO THE MODULES / FONT DRIVERS
- THE TRUETYPE BYTECODE INTERPRETER IS NOW TURNED OFF, in order to
avoid legal problems with the Apple patents. It seems that we
mistakenly turned this option on in previous releases of the
build.
Note that if you want to use the bytecode interpreter in order
to get high-quality TrueType rendering, you will need to toggle
by hand the definition of the
TT_CONFIG_OPTION_BYTECODE_INTERPRETER macro in the file
"include/freetype/config/ftoption.h".
- The CFF driver has been improved by Tom Kacvinsky and Sander van
der Wal:
* Support for "seac" emulation.
* Support for "dotsection".
* Support for retrieving glyph names through
"FT_Get_Glyph_Name".
The first two items are necessary to correctly a large number of
Type 1 fonts converted to the CFF formats by Adobe Acrobat.
- The Type 1 driver was also improved by Tom & others:
* Better EM size computation.
* Better support for synthetic (transformed) fonts.
* The Type 1 driver returns the charstrings corresponding to
each glyph in the "glyph->control_data" field after a call to
"FT_Load_Glyph" (thanks Ha Shao).
- Various other bugfixes, including the following:
* Fixed a nasty memory leak in the Type 1 driver.
* The autohinter and the pcf driver used static writable data
when they shouldn't.
* Many casts were added to make the code more 64-bits safe. It
also now compiles on Windows XP 64-bits without warnings.
* Some incorrect writable statics were removed in the "autohint"
and "pcf" drivers. FreeType 2 now compiles on Epoc again.
II. CHANGES TO THE HIGH-LEVEL API
- The library header files inclusion scheme has been changed. The
old scheme looked like:
#include <freetype/freetype.h>
#include <freetype/ftglyph.h>
#include <freetype/ftcache.h>
#include <freetype/cache/ftimage.h>
Now you should use:
#include <ft2build.h>
#include FT_FREETYPE_H
#include FT_GLYPH_H
#include FT_CACHE_H
#include FT_CACHE_IMAGE_H
NOTE THAT THE OLD INCLUSION SCHEME WILL STILL WORK WITH THIS
RELEASE. HOWEVER, WE DO NOT GUARANTEE THAT THIS WILL STILL BE
TRUE IN THE NEXT ONE (A.K.A. FREETYPE 2.1).
The file <ft2build.h> is used to define the header filename
macros. The complete and commented list of macros is available
in the API reference under the section name "Header File Macros"
in Chapter I.
For more information, see section I of the following document:
http://www.freetype.org/
freetype2/docs/tutorial/step1.html
or
http://freetype.sourceforge.net/
freetype2/docs/tutorial/step1.html
- Many, many comments have been added to the public source file in
order to automatically generate the API Reference through the
"docmaker.py" Python script.
The latter has been updated to support the grouping of sections
in chapters and better index sort. See:
http://www.freetype.org/freetype2/docs/reference/ft2-toc.html
III. CHANGES TO THE BUILD PROCESS
- If you are not building FreeType 2 with its own build system
(but with your own Makefiles or project files), you will need to
be aware that the build process has changed a little bit.
You don't need to put the "src" directory in the include path
when compiling any FT2 component. Instead, simply put the
component's directory in the current include path.
So, if you were doing something like:
cc -c -Iinclude -Isrc src/base/ftbase.c
change the line to:
cc -c -Iinclude -Isrc/base src/base/ftbase.c
If you were doing something like:
cd src/base
cc -c -I../../include -I.. ftbase.c
change it to:
cd src/base
cc -c -I../../include ftbase.c
======================================================================
LATEST CHANGES BETWEEN 2.0.1 and 2.0
2.0.1 introduces a few changes:
- Fixed many bugs related to the support of CFF / OpenType fonts.
These formats are now much better supported though there is
still work planned to deal with charset tables and PDF-embedded
CFF files that use the old "seac" command.
- The library could not be compiled in debug mode with a very
small number of C compilers whose pre-processors didn't
implement the "##" directive correctly (i.e. per se the ANSI C
specification!) An elegant fix was found.
- Added support for the free Borland command-line C++ Builder
compiler. Use "make setup bcc32". Also fixed a few source
lines that generated new warnings with BCC32.
- Fixed a bug in FT_Outline_Get_BBox when computing the extrema of
a conic Bezier arc.
- Updated the INSTALL file to add IDE compilation.
- Other minor bug fixes, from invalid Type 1 style flags to
correct support of synthetic (obliqued) fonts in the
auto-hinter, better support for embedded bitmaps in a SFNT font.
- Fixed some problems with "freetype-config".
Finally, the "standard" scheme for including FreeType headers is now
gradually changing, but this will be explained in a later release
(probably 2.0.2).
And very special thanks to Tom Kacvinsky and YAMANO-UCHI Hidetoshi
for their contributions!
======================================================================
CHANGES BETWEEN beta8 and 2.0
- Changed the default installation path for public headers from
"include/freetype" to "include/freetype2".
Also added a new "freetype-config" that is automatically generated
and installed on Unix and Cygwin systems. The script itself is
used to retrieve the current install path, C compilation flags as
well as linker flags.
- Fixed several small bugs:
* Incorrect max advance width for fixed-pitch Type 1 fonts.
* Incorrect glyph names for certain TrueType fonts.
* The glyph advance was not copied when FT_Glyph_To_Bitmap was
called.
* The linearHoriAdvance and linerVertAdvance fields were not
correctly returned for glyphs processed by the auto-hinter.
* "type1z" renamed back to "type1"; the old "type1" module has
been removed.
- Revamped the build system to make it a lot more generic. This
will allow us to re-use nearly un-modified in lots of other
projects (including FreeType Layout).
- Changed "cid" to use "psaux" too.
- Added the cache sub-system. See <freetype/ftcache.h> as well as
the sources in "src/cache". Note that it compiles but is still
untested for now.
- Updated "docs/docmaker.py", a draft API reference is available at
http://www.freetype.org/ft2api.html.
- Changed "type1" to use "psaux".
- Created a new module named "psaux" to hold the Type 1 & Type 2
parsing routines. It should be used by "type1", "cid", and "cff"
in the future.
- Fixed an important bug in "FT_Glyph_Get_CBox".
- Fixed some compiler warnings that happened since the TrueType
bytecode decoder was deactivated by default.
- Fixed two memory leaks:
* The memory manager (16 bytes) isn't released in
FT_Done_FreeType!
* Using custom input streams, the copy of the original stream was
never released.
- Fixed the auto-hinter by performing automatic computation of the
"filling direction" of each glyph. This is done through a simple
and fast approximation, and seems to work (problems spotted by
Werner though). The Arphic fonts are a lot nicer though there are
still a lot of things to do to handle Asian fonts correctly.
======================================================================
BETA-8 (RELEASE CANDIDATE) CHANGES
- Deactivated the TrueType bytecode interpreter by default.
- Deactivated the "src/type1" font driver. Now "src/type1z" is used
by default.
- Updates to the build system. We now compile the library correctly
under Unix system through "configure" which is automatically
called on the first "make" invocation.
- Added the auto-hinting module! Fixing some bugs here and there.
- Found some bugs in the composite loader (seac) of the Type1-based
font drivers.
- Renamed the directory "freetype2/config" to "freetype2/builds" and
updated all relevant files.
- Found a memory leak in the "type1" driver.
- Incorporated Tom's patches to support flex operators correctly in
OpenType/CFF fonts. Now all I need is to support pure CFF and CEF
fonts to be done with this driver :-)
- Added the Windows FNT/FON driver in "src/winfonts". For now, it
always "simulates" a Unicode charmap, so it shouldn't be
considered completed right now.
It is there to be more a proof of concept than anything else
anyway. The driver is a single C source file, that compiles to 3
Kb of code.
I'm still working on the PCF/BDF drivers, but I'm too lazy to
finish them now.
- CHANGES TO THE HIGH-LEVEL API
* FT_Get_Kerning has a new parameter that allows you to select the
coordinates of the kerning vector (font units, scaled, scaled +
grid-fitted).
* The outline functions are now in <freetype/ftoutln.h> and not
part of <freetype/freetype.h> anymore.
* <freetype/ftmodule.h> now contains declarations for
FT_New_Library, FT_Done_Library, FT_Add_Default_Modules.
* The so-called convenience functions have moved from "ftoutln.c"
to "ftglyph.c", and are thus available with this optional
component of the library. They are declared in
<freetype/ftglyph.h> now.
* Anti-aliased rendering is now the default for FT_Render_Glyph
(i.e. corresponds to render_mode == 0 == ft_render_mode_normal).
To generate a monochrome bitmap, use ft_render_mode_mono, or the
FT_LOAD_MONOCHROME flag in FT_Load_Glyph/FT_Load_Char.
FT_LOAD_ANTI_ALIAS is still defined, but values to 0.
* <freetype/freetype.h> now include <freetype/config/ftconfig.h>,
solving a few headaches :-)
* The type FT_GlyphSlotRec has now a "library" field.
- CHANGES TO THE "ftglyph.h" API
This API has been severely modified in order to make it simpler,
clearer, and more efficient. It certainly now looks like a real
"glyph factory" object, and allows client applications to manage
(i.e. transform, bbox and render) glyph images without ever
knowing their original format.
- Added support for CID-keyed fonts to the CFF driver. Maybe
support for pure CFF + CEF fonts should come in?
- Cleaned up source code in order to avoid two functions with the
same name. Also changed the names of the files in "type1z" from
"t1XXXX" to "z1XXXX" in order to avoid any conflicts.
"make multi" now works well :-)
Also removed the use of "cidafm" for now, even if the source files
are still there. This functionality will certainly go into a
specific module.
- ADDED SUPPORT FOR THE AUTO-HINTER
It works :-) I have a demo program which simply is a copy of
"ftview" that does a `FT_Add_Module(library,
&autohinter_module_class)' after library initialization, and Type
1 & OpenType/CFF fonts are now hinted.
CID fonts are not hinted, as they include no charmap and the
auto-hinter doesn't include "generic" global metrics computations
yet.
Now, I need to release this thing to the FreeType 2 source.
- CHANGES TO THE RENDERER MODULES
The monochrome and smooth renderers are now in two distinct
directories, namely "src/raster1" and "src/smooth". Note that the
old "src/renderer" is now gone.
I ditched the 5-gray-levels renderers. Basically, it involved a
simple #define toggle in 'src/raster1/ftraster.c'.
FT_Render_Glyph, FT_Outline_Render & FT_Outline_Get_Bitmap now
select the best renderer available, depending on render mode. If
the current renderer for a given glyph image format isn't capable
of supporting the render mode, another one will be found in the
library's list. This means that client applications do not need
to switch or set the renderers themselves (as in the latest
change), they'll get what they want automatically. At last.
Changed the demo programs accordingly.
- MAJOR INTERNAL REDESIGN:
A lot of internal modifications have been performed lately on the
source in order to provide the following enhancements:
* More generic module support:
The FT_Module type is now defined to represent a handle to a
given module. The file <freetype/ftmodule.h> contains the
FT_Module_Class definition, as well as the module-loading public
API.
The FT_Driver type is still defined, and still represents a
pointer to a font driver. Note that FT_Add_Driver is replaced
by FT_Add_Module, FT_Get_Driver by FT_Get_Module, etc.
* Support for generic glyph image types:
The FT_Renderer type is a pointer to a module used to perform
various operations on glyph image.
Each renderer is capable of handling images in a single format
(e.g. ft_glyph_format_outline). Its functions are used to:
- transform an glyph image
- render a glyph image into a bitmap
- return the control box (dimensions) of a given glyph image
The scan converters "ftraster.c" and "ftgrays.c" have been moved
to the new directory "src/renderer", and are used to provide two
default renderer modules.
One corresponds to the "standard" scan-converter, the other to
the "smooth" one.
he current renderer can be set through the new function
FT_Set_Renderer.
The old raster-related function FT_Set_Raster, FT_Get_Raster and
FT_Set_Raster_Mode have now disappeared, in favor of the new:
FT_Get_Renderer
FT_Set_Renderer
See the file <freetype/ftrender.h> for more details.
These changes were necessary to properly support different
scalable formats in the future, like bi-color glyphs, etc.
* Glyph loader object:
A new internal object, called a 'glyph loader' has been
introduced in the base layer. It is used by all scalable format
font drivers to load glyphs and composites.
This object has been created to reduce the code size of each
driver, as each one of them basically re-implemented its
functionality.
See <freetype/internal/ftobjs.h> and the FT_GlyphLoader type for
more information.
* FT_GlyphSlot has new fields:
In order to support extended features (see below), the
FT_GlyphSlot structure has a few new fields:
linearHoriAdvance:
This field gives the linearly scaled (i.e. scaled but
unhinted) advance width for the glyph, expressed as a 16.16
fixed pixel value. This is useful to perform WYSIWYG text.
linearVertAdvance:
This field gives the linearly scaled advance height for the
glyph (relevant in vertical glyph layouts only). This is
useful to perform WYSIWYG text.
Note that the two above field replace the removed "metrics2"
field in the glyph slot.
advance:
This field is a vector that gives the transformed advance for
the glyph. By default, it corresponds to the advance width,
unless FT_LOAD_VERTICAL_LAYOUT was specified when calling
FT_Load_Glyph or FT_Load_Char.
bitmap_left:
This field gives the distance in integer pixels from the
current pen position to the left-most pixel of a glyph image
IF IT IS A BITMAP. It is only valid when the "format" field
is set to "ft_glyph_format_bitmap", for example, after calling
the new function FT_Render_Glyph.
bitmap_top:
This field gives the distance in integer pixels from the
current pen position (located on the baseline) to the top-most
pixel of the glyph image IF IT IS A BITMAP. Positive values
correspond to upwards Y.
loader:
This is a new private field for the glyph slot. Client
applications should not touch it.
* Support for transforms and direct rendering in FT_Load_Glyph:
Most of the functionality found in <freetype/ftglyph.h> has been
moved to the core library. Hence, the following:
- A transform can be specified for a face through
FT_Set_Transform. this transform is applied by FT_Load_Glyph
to scalable glyph images (i.e. NOT TO BITMAPS) before the
function returns, unless the bit flag FT_LOAD_IGNORE_TRANSFORM
was set in the load flags.
- Once a glyph image has been loaded, it can be directly
converted to a bitmap by using the new FT_Render_Glyph
function. Note that this function takes the glyph image from
the glyph slot, and converts it to a bitmap whose properties
are returned in "face.glyph.bitmap", "face.glyph.bitmap_left"
and "face.glyph.bitmap_top". The original native image might
be lost after the conversion.
- When using the new bit flag FT_LOAD_RENDER, the FT_Load_Glyph
and FT_Load_Char functions will call FT_Render_Glyph
automatically when needed.
- Reformatted all modules source code in order to get rid of the
basic data types redifinitions (i.e. "TT_Int" instead of "FT_Int",
"T1_Fixed" instead of "FT_Fixed"). Hence the format-specific
prefixes like "TT_", "T1_", "T2_" and "CID_" are only used for
relevant structures.
======================================================================
OLD CHANGES FOR BETA 7
- bug-fixed the OpenType/CFF parser. It now loads and displays my
two fonts nicely, but I'm pretty certain that more testing is
needed :-)
- fixed the crummy Type 1 hinter, it now handles accented characters
correctly (well, the accent is not always well placed, but that's
another problem..)
- added the CID-keyed Type 1 driver in "src/cid". Works pretty well
for only 13 Kb of code ;-) Doesn't read AFM files though, nor the
really useful CMAP files..
- fixed two bugs in the smooth renderer (src/base/ftgrays.c). Thanks
to Boris Letocha for spotting them and providing a fix..
- fixed potential "divide by zero" bugs in ftcalc.c.. my god..
- added source code for the OpenType/CFF driver (still incomplete
though..)
- modified the SFNT driver slightly to perform more robust header
checks in TT_Load_SFNT_Header. This prevents certain font files
(e.g. some Type 1 Multiple Masters) from being incorrectly
"recognized" as TrueType font files..
- moved a lot of stuff from the TrueType driver to the SFNT module,
this allows greater code re-use between font drivers
(e.g. TrueType, OpenType, Compact-TrueType, etc..)
- added a tiny segment cache to the SFNT Charmap 4 decoder, in order
to minimally speed it up..
- added support for Multiple Master fonts in "type1z". There is also
a new file named <freetype/ftmm.h> which defines functions to
manage them from client applications.
The new file "src/base/ftmm.c" is also optional to the engine..
- various formatting changes (e.g. EXPORT_DEF -> FT_EXPORT_DEF) +
small bug fixes in FT_Load_Glyph, the "type1" driver, etc..
- a minor fix to the Type 1 driver to let them apply the font matrix
correctly (used for many oblique fonts..)
- some fixes for 64-bit systems (mainly changing some FT_TRACE calls
to use %p instead of %lx).. Thanks to Karl Robillard
- fixed some bugs in the sbit loader (src/base/sfnt/ttsbit.c) +
added a new flag, FT_LOAD_CROP_BITMAP to query that bitmaps be
cropped when loaded from a file (maybe I should move the bitmap
cropper to the base layer ??).
- changed the default number of gray levels of the smooth renderer
to 256 (instead of the previous 128). Of course, the human eye
can't see any difference ;-)
- removed TT_MAX_SUBGLYPHS, there is no static limit on the number
of subglyphs in a TrueType font now..
======================================================================
OLD CHANGES 16 May 2000
- tagged "BETA-6" in the CVS tree. This one is a serious release
candidate even though it doesn't incorporate the auto-hinter yet..
- various obsolete files were removed, and copyright header updated
- finally updated the standard raster to fix the monochrome
rendering bug + re-enable support for 5-gray levels anti-aliasing
(suck, suck..)
- created new header files, and modified sources accordingly:
<freetype/fttypes.h>
- simple FreeType types, without the API
<freetype/internal/ftmemory.h>
- definition of memory-management macros
- added the "DSIG" (OpenType Digital Signature) tag to
<freetype/tttags.h>
- light update/cleaning of the build system + changes to the sources
in order to get rid of _all_ compiler warnings with three
compilers, i.e:
gcc with "-ansi -pedantic -Wall -W", Visual C++ with "/W3 /WX" and
LCC
IMPORTANT NOTE FOR WIN32-LCC USERS:
|
| It seems the C pre-processor that comes with LCC is broken, it
| doesn't recognize the ANSI standard directives # and ##
| correctly when one of the argument is a macro. Also, something
| like:
|
| #define F(x) print##x
|
| F(("hello"))
|
| will get incorrectly translated to:
|
| print "hello")
|
| by its pre-processor. For this reason, you simply cannot build
| FreeType 2 in debug mode with this compiler..
- yet another massive grunt work. I've changed the definition of the
EXPORT_DEF, EXPORT_FUNC, BASE_DEF & BASE_FUNC macros. These now
take an argument, which is the function's return value type.
This is necessary to compile FreeType as a DLL on Windows and
OS/2. Depending on the compiler used, a compiler-specific keyword
like __export or __system must be placed before (VisualC++) or
after (BorlandC++) the type..
Of course, this needed a lot of changes throughout the source code
to make it compile again... All cleaned up now, apparently..
Note also that there is a new EXPORT_VAR macro defined to allow
the _declaration_ of an exportable public (constant)
variable. This is the case of the raster interfaces (see
ftraster.h and ftgrays.h), as well as each module's interface (see
sfdriver.h, psdriver.h, etc..)
- new feature: it is now possible to pass extra parameters to font
drivers when creating a new face object. For now,
this capability is unused. It could however prove to
be useful in a near future..
the FT_Open_Args structure was changes, as well as the internal
driver interface (the specific "init_face" module function has
now a different signature).
- updated the tutorial (not finished though).
- updated the top-level BUILD document
- fixed a potential memory leak that could occur when loading
embedded bitmaps.
- added the declaration of FT_New_Memory_Face in
<freetype/freetype.h>, as it was missing from the public header
(the implementation was already in "ftobjs.c").
- the file <freetype/fterrors.h> has been seriously updated in order
to allow the automatic generation of error message tables. See the
comments within it for more information.
- major directory hierarchy re-organisation. This was done for two
things:
* first, to ease the "manual" compilation of the library by
requiring at lot less include paths :-)
* second, to allow external programs to effectively access
internal data fields. For example, this can be extremely
useful if someone wants to write a font producer or a font
manager on top of FreeType.
Basically, you should now use the 'freetype/' prefix for header
inclusion, as in:
#include <freetype/freetype.h>
#include <freetype/ftglyph.h>
Some new include sub-directories are available:
a. the "freetype/config" directory, contains two files used to
configure the build of the library. Client applications should
not need to look at these normally, but they can if they want.
#include <freetype/config/ftoption.h>
#include <freetype/config/ftconfig.h>
b. the "freetype/internal" directory, contains header files that
describes library internals. These are the header files that
were previously found in the "src/base" and "src/shared"
directories.
As usual, the build system and the demos have been updated to
reflect the change..
Here's a layout of the new directory hierarchy:
TOP
include/
freetype/
freetype.h
...
config/
ftoption.h
ftconfig.h
ftmodule.h
internal/
ftobjs.h
ftstream.h
ftcalc.h
...
src/
base/
...
sfnt/
psnames/
truetype/
type1/
type1z/
Compiling a module is now much easier, for example, the following
should work when in the TOP directory on an ANSI build:
gcc -c -I./include -I./src/base src/base/ftbase.c
gcc -c -I./include -I./src/sfnt src/sfnt/sfnt.c
etc..
(of course, using -Iconfig/<system> if you provide system-specific
configuration files).
- updated the structure of FT_Outline_Funcs in order to allow direct
coordinate scaling within the outline decomposition routine (this
is important for virtual "on" points with TrueType outlines) +
updates to the rasters to support this..
- updated the OS/2 table loading code in "src/sfnt/ttload.c" in
order to support version 2 of the table (see OpenType 1.2 spec)
- created "include/tttables.h" and "include/t1tables.h" to allow
client applications to access some of the SFNT and T1 tables of a
face with a procedural interface (see FT_Get_Sfnt_Table()) +
updates to internal source files to reflect the change..
- some cleanups in the source code to get rid of warnings when
compiling with the "-Wall -W -ansi -pedantic" options in gcc.
- debugged and moved the smooth renderer to "src/base/ftgrays.c" and
its header to "include/ftgrays.h"
- updated TT_MAX_SUBGLYPHS to 96 as some CJK fonts have composites
with up to 80 sub-glyphs !! Thanks to Werner
======================================================================
OLD CHANGES - 14-apr-2000
- fixed a bug in the TrueType glyph loader that prevented the
correct loading of some CJK glyphs in mingli.ttf
- improved the standard Type 1 hinter in "src/type1"
- fixed two bugs in the experimental Type 1 driver in "src/type1z"
to handle the new XFree86 4.0 fonts (and a few other ones..)
- the smooth renderer is now complete and supports sub-banding to
render large glyphs at high speed. However, it is still located in
"demos/src/ftgrays.c" and should move to the library itself in the
next beta.. NOTE: The smooth renderer doesn't compile in
stand-alone mode anymore, but this should be fixed RSN..
- introduced convenience functions to more easily deal with glyph
images, see "include/ftglyph.h" for more details, as well as the
new demo program named "demos/src/ftstring.c" that demonstrates
its use
- implemented FT_LOAD_NO_RECURSE in both the TrueType and Type 1
drivers (this is required by the auto-hinter to improve its
results).
- changed the raster interface, in order to allow client
applications to provide their own span-drawing callbacks. However,
only the smooth renderer supports this. See "FT_Raster_Params" in
the file "include/ftimage.h"
- fixed a small bug in FT_MulFix that caused incorrect transform
computation!
- Note: The tutorial is out-of-date, grumpf.. :-(
======================================================================
OLD CHANGES - 12-mar-2000
- changed the layout of configuration files : now, all ANSI
configuration files are located in
"freetype2/config". System-specific over-rides can be placed in
"freetype2/config/<system>".
- moved all configuration macros to "config/ftoption.h"
- improvements in the Type 1 driver with AFM support
- changed the fields in the FT_Outline structure : the old "flags"
array is re-named "tags", while all ancient flags are encoded into
a single unsigned int named "flags".
- introduced new flags in FT_Outline.flags (see
ft_outline_.... enums in "ftimage.h").
- changed outline functions to "FT_Outline_<action>" syntax
- added a smooth anti-alias renderer to the demonstration programs
- added Mac graphics driver (thanks Just)
- FT_Open_Face changed in order to received a pointer to a
FT_Open_Args descriptor..
- various cleanups, a few more API functions implemented (see
FT_Attach_File)
- updated some docs
======================================================================
OLD CHANGES - 22-feb-2000
- introduced the "psnames" module. It is used to:
o convert a Postscript glyph name into the equivalent Unicode
character code (used by the Type 1 driver(s) to synthetize on
the fly a Unicode charmap).
o provide an interface to retrieve the Postscript names of the
Macintosh, Adobe Standard & Adobe Expert character codes.
(the Macintosh names are used by the SFNT-module postscript
names support routines, while the other two tables are used by
the Type 1 driver(s)).
- introduced the "type1z" alternate Type 1 driver. This is a (still
experimental) driver for the Type 1 format that will ultimately
replace the one in "src/type1". It uses pattern matching to load
data from the font, instead of a finite state analyzer. It works
much better than the "old" driver with "broken" fonts. It is also
much smaller (under 15 Kb).
- the Type 1 drivers (both in "src/type1" and "src/type1z") are
nearly complete. They both provide automatic Unicode charmap
synthesis through the "psnames" module. No re-encoding vector is
needed. (note that they still leak memory due to some code
missing, and I'm getting lazy).
Trivial AFM support has been added to read kerning information but
wasn't exactly tested as it should ;-)
- The TrueType glyph loader has been seriously rewritten (see the
file "src/truetype/ttgload.c". It is now much, much simpler as
well as easier to read, maintain and understand :-) Preliminary
versions introduced a memory leak that has been reported by Jack
Davis, and is now fixed..
- introduced the new "ft_glyph_format_plotter", used to represent
stroked outlines like Windows "Vector" fonts, and certain Type 1
fonts like "Hershey". The corresponding raster will be written
soon.
- FT_New_Memory_Face is gone. Likewise, FT_Open_Face has a new
interface that uses a structure to describe the input stream, the
driver (if required), etc..
TODO
- Write FT_Get_Glyph_Bitmap and FT_Load_Glyph_Bitmap
- Add a function like FT_Load_Character( face, char_code, load_flags
) that would really embbed a call to FT_Get_Char_Index then
FT_Load_Glyph to ease developer's work.
- Update the tutorial!
- consider adding support for Multiple Master fonts in the Type 1
drivers.
- Test the AFM routines of the Type 1 drivers to check that kerning
information is returned correctly.
- write a decent auto-gridding component !! We need this to release
FreeType 2.0 gold !
less urgent needs:
- add a CFF/Type2 driver
- add a BDF driver
- add a FNT/PCF/HBF driver
- add a Speedo driver from the X11 sources
======================================================================
OLDER CHANGES - 27-jan-2000
- updated the "sfnt" module interface to allow several SFNT-based
drivers to co-exist peacefully
- updated the "T1_Face" type to better separate Postscript font
content from the rest of the FT_Face structure. Might be used
later by the CFF/Type2 driver..
- added an experimental replacement Type 1 driver featuring advanced
(and speedy) pattern matching to retrieve the data from postscript
fonts.
- very minor changes in the implementation of FT_Set_Char_Size and
FT_Set_Pixel_Sizes (they now implement default to ligthen the font
driver's code).
======================================================================
OLD MESSAGE
This file summarizes the changes that occured since the last "beta" of
FreeType 2. Because the list is important, it has been divided into
separate sections:
Table Of Contents:
I High-Level Interface (easier !)
II Directory Structure
III Glyph Image Formats
IV Build System
V Portability
VI Font Drivers
----------------------------------------------------------------------
High-Level Interface:
The high-level API has been considerably simplified. Here is how:
- resource objects have disappeared. this means that face objects
can now be created with a single function call (see FT_New_Face
and FT_Open_Face)
- when calling either FT_New_Face & FT_Open_Face, a size object
and a glyph slot object are automatically created for the face,
and can be accessed through "face->glyph" and "face->size" if
one really needs to. In most cases, there's no need to call
FT_New_Size or FT_New_Glyph.
- similarly, FT_Load_Glyph now only takes a "face" argument
(instead of a glyph slot and a size). Also, it's "result"
parameter is gone, as the glyph image type is returned in the
field "face->glyph.format"
- the list of available charmaps is directly accessible through
"face->charmaps", counting "face->num_charmaps" elements. Each
charmap has an 'encoding' field which specifies which known
encoding it deals with. Valid values are, for example :
ft_encoding_unicode (for ASCII, Latin-1 and Unicode)
ft_encoding_apple_roman
ft_encoding_sjis
ft_encoding_adobe_standard
ft_encoding_adobe_expert
other values may be added in the future. Each charmap still
holds its "platform_id" and "encoding_id" values in case the
encoding is too exotic for the current library
----------------------------------------------------------------------
Directory Structure:
Should seem obvious to most of you:
freetype/
config/ -- configuration sub-makefiles
ansi/
unix/ -- platform-specific configuration files
win32/
os2/
msdos/
include/ -- public header files, those to be included
directly by client apps
src/ -- sources of the library
base/ -- the base layer
sfnt/ -- the sfnt "driver" (see the drivers section
below)
truetype/ -- the truetype driver
type1/ -- the type1 driver
shared/ -- some header files shared between drivers
demos/ -- demos/tools
docs/ -- documentation (a bit empty for now)
----------------------------------------------------------------------
Glyph Image Formats:
Drivers are now able to register new glyph image formats within the
library. For now, the base layer supports of course bitmaps and
vector outlines, but one could imagine something different like
colored bitmaps, bi-color vectors or wathever else (Metafonts anyone
??).
See the file `include/ftimage.h'. Note also that the type
FT_Raster_Map is gone, and is now replaced by FT_Bitmap, which
should encompass all known bitmap types.
Each new image format must provide at least one "raster", i.e. a
module capable of transforming the glyph image into a bitmap. It's
also possible to change the default raster used for a given glyph
image format.
The default outline scan-converter now uses 128 levels of grays by
default, which tends to smooth many things. Note that the demo
programs have been updated significantly in order to display these..
----------------------------------------------------------------------
Build system:
You still need GNU Make to build the library. The build system has
been very seriously re-vamped in order to provide things like :
- automatic host platform detection (reverting to 'config/ansi' if
it is not detected, with pseudo-standard compilation flags)
- the ability to compile from the Makefiles with very different and
exotic compilers. Note that linking the library can be difficult
for some platforms.
For example, the file `config/win32/lcclib.bat' is invoked by the
build system to create the ".lib" file with LCC-Win32 because its
librarian has too many flaws to be invoked directly from the
Makefile.
Here's how it works:
- the first time you type `make', the build system runs a series of
sub-makefiles in order to detect your host platform. It then dumps
what it found, and creates a file called `config.mk' in the
current directory. This is a sub-Makefile used to define many
important Make variables used to build the library.
- the second time, the build system detects the `config.mk' then use
it to build the library. All object files go into 'obj' by
default, as well as the library file, but this can easily be
changed.
Note that you can run "make setup" to force another host platform
detection even if a `config.mk' is present in the current
directory. Another solution is simply to delete the file, then
re-run make.
Finally, the default compiler for all platforms is gcc (for now,
this will hopefully changed in the future). You can however specify
a different compiler by specifying it after the 'setup' target as
in:
gnumake setup lcc on Win32 to use the LCC compiler
gnumake setup visualc on Win32 to use Visual C++
See the file `config/<system>/detect.mk' for a list of supported
compilers for your platforms.
It should be relatively easy to write new detection rules files and
config.mk..
Finally, to build the demo programs, go to `demos' and launch GNU
Make, it will use the `config.mk' in the top directory to build the
test programs..
----------------------------------------------------------------------
Portability:
In the previous beta, a single FT_System object was used to
encompass all low-level operations like thread synchronisation,
memory management and i/o access. This has been greatly simplified:
- thread synchronisation has been dropped, for the simple reason
that the library is already re-entrant, and that if you really
need two threads accessing the same FT_Library, you should
really synchronize access to it yourself with a simple mutex.
- memory management is performed through a very simple object
called "FT_Memory", which really is a table containing a table
of pointers to functions like malloc, realloc and free as well
as some user data (closure).
- resources have disappeared (they created more problems than they
solved), and i/o management have been simplified greatly as a
result. Streams are defined through FT_Stream objects, which can
be either memory-based or disk-based.
Note that each face has its own stream, which is closed only
when the face object is destroyed. Hence, a function like
TT_Flush_Face in 1.x cannot be directly supported. However, if
you really need something like this, you can easily tailor your
own streams to achieve the same feature at a lower level (and
use FT_Open_Face instead of FT_New_Face to create the face).
See the file "include/ftsystem.h" for more details, as well as the
implementations found in "config/unix" and "config/ansi".
----------------------------------------------------------------------
Font Drivers:
The Font Driver interface has been modified in order to support
extensions & versioning.
The list of the font drivers that are statically linked to the
library at compile time is managed through a new configuration file
called `config/<platform>/ftmodule.h'.
This file is autogenerated when invoking `make modules'. This target
will parse all sub-directories of 'src', looking for a "module.mk"
rules file, used to describe the driver to the build system.
Hence, one should call `make modules' each time a font driver is
added or removed from the `src' directory.
Finally, this version provides a "pseudo-driver" in `src/sfnt'. This
driver doesn't support font files directly, but provides services
used by all TrueType-like font drivers. Hence, its code is shared
between the TrueType & OpenType font formats, and possibly more
formats to come if we're lucky..
----------------------------------------------------------------------
Extensions support:
The extensions support is inspired by the one found in 1.x.
Now, each font driver has its own "extension registry", which lists
which extensions are available for the font faces managed by the
driver.
Extension ids are now strings, rather than 4-byte tags, as this is
usually more readable..
Each extension has:
- some data, associated to each face object
- an interface (table of function pointers)
An extension that is format-specific should simply register itself
to the correct font driver. Here is some example code:
// Registering an extensions
//
FT_Error FT_Init_XXXX_Extension( FT_Library library )
{
FT_DriverInterface* tt_driver;
driver = FT_Get_Driver( library, "truetype" );
if (!driver) return FT_Err_Unimplemented_Feature;
return FT_Register_Extension( driver, &extension_class );
}
// Implementing the extensions
//
FT_Error FT_Proceed_Extension_XXX( FT_Face face )
{
FT_XXX_Extension ext;
FT_XXX_Extension_Interface ext_interface;
ext = FT_Get_Extension( face, "extensionid", &ext_interface );
if (!ext) return error;
return ext_interface->do_it(ext);
}
--- end of CHANGES ---
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