04aa800ce9
fixed two bugs in the smooth renderer
634 lines
24 KiB
Plaintext
634 lines
24 KiB
Plaintext
LATEST_CHANGES
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- added the CID-keyed Type 1 driver in "src/cid". Works pretty well for
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only 13 Kb of code ;-) Doesn't read AFM files though, nor the really
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useful CMAP files..
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- fixed two bugs in the smooth renderer (src/base/ftgrays.c). Thanks to
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Boris Letocha for spotting them and providing a fix..
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- fixed potential "divide by zero" bugs in ftcalc.c.. my god..
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- added source code for the OpenType/CFF driver (still incomplete though..)
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- modified the SFNT driver slightly to perform more robust header
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checks in TT_Load_SFNT_Header. This prevents certain font files
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(e.g. some Type 1 Multiple Masters) from being incorrectly "recognized"
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as TrueType font files..
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- moved a lot of stuff from the TrueType driver to the SFNT module,
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this allows greater code re-use between font drivers (e.g. TrueType,
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OpenType, Compact-TrueType, etc..)
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- added a tiny segment cache to the SFNT Charmap 4 decoder, in order
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to minimally speed it up..
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- added support for Multiple Master fonts in "type1z". There is also
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a new file named <freetype/ftmm.h> which defines functions to
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manage them from client applications.
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The new file "src/base/ftmm.c" is also optional to the engine..
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- various formatting changes (e.g. EXPORT_DEF -> FT_EXPORT_DEF) +
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small bug fixes in FT_Load_Glyph, the "type1" driver, etc..
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- a minor fix to the Type 1 driver to let them apply the font matrix
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correctly (used for many oblique fonts..)
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- some fixes for 64-bit systems (mainly changing some FT_TRACE calls
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to use %p instead of %lx).. Thanks to Karl Robillard
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- fixed some bugs in the sbit loader (src/base/sfnt/ttsbit.c) + added
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a new flag, FT_LOAD_CROP_BITMAP to query that bitmaps be cropped when
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loaded from a file (maybe I should move the bitmap cropper to the
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base layer ??).
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- changed the default number of gray levels of the smooth renderer to
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256 (instead of the previous 128). Of course, the human eye can't
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see any difference ;-)
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- removed TT_MAX_SUBGLYPHS, there is no static limit on the number of
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subglyphs in a TrueType font now..
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=============================================================================
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OLD CHANGES 16 May 2000
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- tagged "BETA-6" in the CVS tree. This one is a serious release candidate
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even though it doesn't incorporate the auto-hinter yet..
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- various obsolete files were removed, and copyright header updated
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- finally updated the standard raster to fix the monochrome rendering bug
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+ re-enable support for 5-gray levels anti-aliasing (suck, suck..)
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- created new header files, and modified sources accordingly:
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<freetype/fttypes.h> - simple FreeType types, without the API
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<freetype/internal/ftmemory.h> - definition of memory-management macros
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- added the "DSIG" (OpenType Digital Signature) tag to <freetype/tttags.h>
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- light update/cleaning of the build system + changes to the sources in
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order to get rid of _all_ compiler warnings with three compilers, i.e:
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gcc with "-ansi -pedantic -Wall -W", Visual C++ with "/W3 /WX"
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and LCC
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IMPORTANT NOTE FOR WIN32-LCC USERS:
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| It seems the C pre-processor that comes with LCC is broken, it
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| doesn't recognize the ANSI standard directives # and ## correctly
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| when one of the argument is a macro. Also, something like:
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| #define F(x) print##x
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| F(("hello"))
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| will get incorrectly translated to:
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| print "hello")
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| by its pre-processor. For this reason, you simply cannot build
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| FreeType 2 in debug mode with this compiler..
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- yet another massive grunt work. I've changed the definition of the
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EXPORT_DEF, EXPORT_FUNC, BASE_DEF & BASE_FUNC macros. These now take
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an argument, which is the function's return value type.
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This is necessary to compile FreeType as a DLL on Windows and OS/2.
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Depending on the compiler used, a compiler-specific keyword like __export
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or __system must be placed before (VisualC++) or after (BorlandC++)
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the type..
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Of course, this needed a lot of changes throughout the source code
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to make it compile again... All cleaned up now, apparently..
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Note also that there is a new EXPORT_VAR macro defined to allow the
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_declaration_ of an exportable public (constant) variable. This is the
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case of the raster interfaces (see ftraster.h and ftgrays.h), as well
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as each module's interface (see sfdriver.h, psdriver.h, etc..)
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- new feature: it is now possible to pass extra parameters to font
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drivers when creating a new face object. For now, this
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capability is unused. It could however prove to be useful
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in a near future..
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the FT_Open_Args structure was changes, as well as the internal
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driver interface (the specific "init_face" module function has now
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a different signature).
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- updated the tutorial (not finished though).
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- updated the top-level BUILD document
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- fixed a potential memory leak that could occur when loading embedded
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bitmaps.
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- added the declaration of FT_New_Memory_Face in <freetype/freetype.h>, as
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it was missing from the public header (the implementation was already
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in "ftobjs.c").
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- the file <freetype/fterrors.h> has been seriously updated in order to
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allow the automatic generation of error message tables. See the comments
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within it for more information.
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- major directory hierarchy re-organisation. This was done for two things:
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* first, to ease the "manual" compilation of the library by requiring
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at lot less include paths :-)
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* second, to allow external programs to effectively access internal
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data fields. For example, this can be extremely useful if someone
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wants to write a font producer or a font manager on top of FreeType.
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Basically, you should now use the 'freetype/' prefix for header inclusion,
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as in:
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#include <freetype/freetype.h>
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#include <freetype/ftglyph.h>
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Some new include sub-directories are available:
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a. the "freetype/config" directory, contains two files used to
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configure the build of the library. Client applications should
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not need to look at these normally, but they can if they want.
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#include <freetype/config/ftoption.h>
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#include <freetype/config/ftconfig.h>
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b. the "freetype/internal" directory, contains header files that
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describes library internals. These are the header files that were
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previously found in the "src/base" and "src/shared" directories.
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As usual, the build system and the demos have been updated to reflect
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the change..
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Here's a layout of the new directory hierarchy:
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TOP
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include/
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freetype/
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freetype.h
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...
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config/
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ftoption.h
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ftconfig.h
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ftmodule.h
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internal/
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ftobjs.h
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ftstream.h
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ftcalc.h
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...
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src/
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base/
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...
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sfnt/
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psnames/
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truetype/
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type1/
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type1z/
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Compiling a module is now much easier, for example, the following should
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work when in the TOP directory on an ANSI build:
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gcc -c -I./include -I./src/base src/base/ftbase.c
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gcc -c -I./include -I./src/sfnt src/sfnt/sfnt.c
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etc..
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(of course, using -Iconfig/<system> if you provide system-specific
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configuration files).
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- updated the structure of FT_Outline_Funcs in order to allow
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direct coordinate scaling within the outline decomposition routine
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(this is important for virtual "on" points with TrueType outlines)
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+ updates to the rasters to support this..
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- updated the OS/2 table loading code in "src/sfnt/ttload.c" in order
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to support version 2 of the table (see OpenType 1.2 spec)
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- created "include/tttables.h" and "include/t1tables.h" to allow
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client applications to access some of the SFNT and T1 tables of a
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face with a procedural interface (see FT_Get_Sfnt_Table())
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+ updates to internal source files to reflect the change..
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- some cleanups in the source code to get rid of warnings when compiling
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with the "-Wall -W -ansi -pedantic" options in gcc.
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- debugged and moved the smooth renderer to "src/base/ftgrays.c" and
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its header to "include/ftgrays.h"
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- updated TT_MAX_SUBGLYPHS to 96 as some CJK fonts have composites with
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up to 80 sub-glyphs !! Thanks to Werner
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================================================================================
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OLD CHANGES - 14-apr-2000
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- fixed a bug in the TrueType glyph loader that prevented the correct
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loading of some CJK glyphs in mingli.ttf
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- improved the standard Type 1 hinter in "src/type1"
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- fixed two bugs in the experimental Type 1 driver in "src/type1z"
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to handle the new XFree86 4.0 fonts (and a few other ones..)
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- the smooth renderer is now complete and supports sub-banding
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to render large glyphs at high speed. However, it is still located
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in "demos/src/ftgrays.c" and should move to the library itself
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in the next beta.. NOTE: The smooth renderer doesn't compile in
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stand-alone mode anymore, but this should be fixed RSN..
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- introduced convenience functions to more easily deal with glyph
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images, see "include/ftglyph.h" for more details, as well as the
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new demo program named "demos/src/ftstring.c" that demonstrates
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its use
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- implemented FT_LOAD_NO_RECURSE in both the TrueType and Type 1
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drivers (this is required by the auto-hinter to improve its results).
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- changed the raster interface, in order to allow client applications
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to provide their own span-drawing callbacks. However, only the
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smooth renderer supports this. See "FT_Raster_Params" in the
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file "include/ftimage.h"
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- fixed a small bug in FT_MulFix that caused incorrect transform
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computation !!
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- Note: The tutorial is out-of-date, grumpf.. :-(
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================================================================================
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OLD CHANGES - 12-mar-2000
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- changed the layout of configuration files : now, all ANSI configuration
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files are located in "freetype2/config". System-specific over-rides
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can be placed in "freetype2/config/<system>".
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- moved all configuration macros to "config/ftoption.h"
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- improvements in the Type 1 driver with AFM support
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- changed the fields in the FT_Outline structure : the old "flags"
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array is re-named "tags", while all ancient flags are encoded into
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a single unsigned int named "flags".
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- introduced new flags in FT_Outline.flags (see ft_outline_.... enums in
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"ftimage.h").
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- changed outline functions to "FT_Outline_<action>" syntax
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- added a smooth anti-alias renderer to the demonstration programs
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- added Mac graphics driver (thanks Just)
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- FT_Open_Face changed in order to received a pointer to a FT_Open_Args
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descriptor..
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- various cleanups, a few more API functions implemented (see FT_Attach_File)
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- updated some docs
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================================================================================
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OLD CHANGES - 22-feb-2000
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- introduced the "psnames" module. It is used to:
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o convert a Postscript glyph name into the equivalent Unicode
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character code (used by the Type 1 driver(s) to synthetize
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on the fly a Unicode charmap).
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o provide an interface to retrieve the Postscript names of
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the Macintosh, Adobe Standard & Adobe Expert character codes.
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(the Macintosh names are used by the SFNT-module postscript
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names support routines, while the other two tables are used
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by the Type 1 driver(s)).
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- introduced the "type1z" alternate Type 1 driver. This is a (still
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experimental) driver for the Type 1 format that will ultimately
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replace the one in "src/type1". It uses pattern matching to load
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data from the font, instead of a finite state analyzer. It works
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much better than the "old" driver with "broken" fonts. It is also
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much smaller (under 15 Kb).
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- the Type 1 drivers (both in "src/type1" and "src/type1z") are
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nearly complete. They both provide automatic Unicode charmap
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synthesis through the "psnames" module. No re-encoding vector
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is needed. (note that they still leak memory due to some code
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missing, and I'm getting lazy).
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Trivial AFM support has been added to read kerning information
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but wasn't exactly tested as it should ;-)
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- The TrueType glyph loader has been seriously rewritten (see the
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file "src/truetype/ttgload.c". It is now much, much simpler as
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well as easier to read, maintain and understand :-) Preliminary
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versions introduced a memory leak that has been reported by Jack
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Davis, and is now fixed..
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- introduced the new "ft_glyph_format_plotter", used to represent
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stroked outlines like Windows "Vector" fonts, and certain Type 1
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fonts like "Hershey". The corresponding raster will be written
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soon.
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- FT_New_Memory_Face is gone. Likewise, FT_Open_Face has a new
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interface that uses a structure to describe the input stream,
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the driver (if required), etc..
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TODO
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- Write FT_Get_Glyph_Bitmap and FT_Load_Glyph_Bitmap
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- Add a function like FT_Load_Character( face, char_code, load_flags )
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that would really embbed a call to FT_Get_Char_Index then FT_Load_Glyph
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to ease developer's work.
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- Update the tutorial !!
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- consider adding support for Multiple Master fonts in the Type 1
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drivers.
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- Test the AFM routines of the Type 1 drivers to check that kerning
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information is returned correctly.
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- write a decent auto-gridding component !! We need this to release
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FreeType 2.0 gold !
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----- less urgent needs : ----------
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- add a CFF/Type2 driver
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- add a BDF driver
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- add a FNT/PCF/HBF driver
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- add a Speedo driver from the X11 sources
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==============================================================================
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OLDER CHANGES - 27-jan-2000
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- updated the "sfnt" module interface to allow several SFNT-based
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drivers to co-exist peacefully
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- updated the "T1_Face" type to better separate Postscript font content
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from the rest of the FT_Face structure. Might be used later by the
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CFF/Type2 driver..
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- added an experimental replacement Type 1 driver featuring advanced
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(and speedy) pattern matching to retrieve the data from postscript
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fonts.
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- very minor changes in the implementation of FT_Set_Char_Size and
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FT_Set_Pixel_Sizes (they now implement default to ligthen the
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font driver's code).
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=============================================================================
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OLD MESSAGE
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This file summarizes the changes that occured since the last "beta" of FreeType 2.
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Because the list is important, it has been divided into separate sections:
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Table Of Contents:
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I High-Level Interface (easier !)
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II Directory Structure
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III Glyph Image Formats
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IV Build System
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V Portability
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VI Font Drivers
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-----------------------------------------------------------------------------------------
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High-Level Interface :
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The high-level API has been considerably simplified. Here is how :
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- resource objects have disappeared. this means that face objects can
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now be created with a single function call (see FT_New_Face and
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FT_Open_Face)
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- when calling either FT_New_Face & FT_Open_Face, a size object and a
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glyph slot object are automatically created for the face, and can be
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accessed through "face->glyph" and "face->size" if one really needs to.
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In most cases, there's no need to call FT_New_Size or FT_New_Glyph.
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- similarly, FT_Load_Glyph now only takes a "face" argument (instead of
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a glyph slot and a size). Also, it's "result" parameter is gone, as
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the glyph image type is returned in the field "face->glyph.format"
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- the list of available charmaps is directly accessible through
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"face->charmaps", counting "face->num_charmaps" elements. Each
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charmap has an 'encoding' field which specifies which known encoding
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it deals with. Valid values are, for example :
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ft_encoding_unicode (for ASCII, Latin-1 and Unicode)
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ft_encoding_apple_roman
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ft_encoding_sjis
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ft_encoding_adobe_standard
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ft_encoding_adobe_expert
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other values may be added in the future. Each charmap still holds its
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"platform_id" and "encoding_id" values in case the encoding is too
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exotic for the current library
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-----------------------------------------------------------------------------------------
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Directory Structure:
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Should seem obvious to most of you:
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freetype/
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config/ -- configuration sub-makefiles
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ansi/
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unix/ -- platform-specific configuration files
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win32/
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os2/
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msdos/
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include/ -- public header files, those to be included directly
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by client apps
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src/ -- sources of the library
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base/ -- the base layer
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sfnt/ -- the sfnt "driver" (see the drivers section below)
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truetype/ -- the truetype driver
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type1/ -- the type1 driver
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shared/ -- some header files shared between drivers
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demos/ -- demos/tools
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docs/ -- documentation (a bit empty for now)
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-----------------------------------------------------------------------------------------
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Glyph Image Formats :
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Drivers are now able to register new glyph image formats within the library.
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For now, the base layer supports of course bitmaps and vector outlines, but
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one could imagine something different like colored bitmaps, bi-color
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vectors or wathever else (Metafonts anyone ??).
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See the file `include/ftimage.h'. Note also that the type FT_Raster_Map is
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gone, and is now replaced by FT_Bitmap, which should encompass all known
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bitmap types.
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Each new image format must provide at least one "raster", i.e. a module
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capable of transforming the glyph image into a bitmap. It's also possible
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to change the default raster used for a given glyph image format.
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The default outline scan-converter now uses 128 levels of grays by default,
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which tends to smooth many things. Note that the demo programs have been
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updated significantly in order to display these..
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-----------------------------------------------------------------------------------------
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Build system :
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You still need GNU Make to build the library. The build system has been
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very seriously re-vamped in order to provide things like :
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- automatic host platform detection (reverting to 'config/ansi'
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if it is not detected, with pseudo-standard compilation flags)
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- the ability to compile from the Makefiles with very different and
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exotic compilers. Note that linking the library can be difficult for
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some platforms.
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For example, the file `config/win32/lcclib.bat' is invoked by the
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build system to create the ".lib" file with LCC-Win32 because its
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librarian has too many flaws to be invoked directly from the Makefile.
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Here's how it works :
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- the first time you type `make', the build system runs a series of
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sub-makefiles in order to detect your host platform. It then dumps
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what it found, and creates a file called `config.mk' in the current
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directory. This is a sub-Makefile used to define many important Make
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variables used to build the library.
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- the second time, the build system detects the `config.mk' then use it
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to build the library. All object files go into 'obj' by default, as
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well as the library file, but this can easily be changed.
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Note that you can run "make setup" to force another host platform detection
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|
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);
|
|
}
|
|
|