This is the large, famous `Infinality' patch to support ClearType
bytecode which has been available from
http://www.infinality.net/blog/ for some time, and which has been
refined over the last years. While still experimental, it is now
mature enough to be included directly into FreeType.
Most of the code is based on the ClearType whitepaper written by
Greg Hitchcock
http://www.microsoft.com/typography/cleartype/truetypecleartype.aspx
which gives a detailed overview of the necessary changes to the
Microsoft rasterizer so that older fonts are supported. However, a
lot of details are still missing, and this patches provides a
framework to easily handle rendering issues down to the glyph level
of certain fonts.
Note that ClearType support is not completely implemented! In
particular, full support for the options `compatible_widths',
`symmetrical_smoothing, and `bgr' (via the GETINFO bytecode
instruction) is missing.
* src/truetype/ttsubpix.c: New file, providing code to handle
`tweaks', this is, rules for certain glyphs in certain fonts
(including wildcards) which need a special treatment.
* src/truetype/ttsubpix.h: New file, holding the tweaking rules.
* include/freetype/config/ftoption.h, src/devel/ftoption.h
(TT_CONFIG_OPTION_SUBPIXEL_HINTING): New macro.
* include/freetype/internal/ftobjs.h (FT_PIX_FLOOR_GRID,
FT_PIX_ROUND_GRID, FT_PIX_CEIL_GRID): New macros.
* src/truetype/truetype.c [TT_USE_BYTECODE_INTERPRETER]: Include
`ttsubpix.c'.
* src/truetype/ttgload.c: Include `ttsubpix.h'.
[All changes below are guarded by TT_CONFIG_OPTION_SUBPIXEL_HINTING.]
(tt_get_metrics): Set tweak flags.
(TT_Hint_Glyph): Call `FT_Outline_EmboldenXY' if necessary.
(TT_Process_Simple_Glyph): Compensate emboldening if necessary.
(compute_glyph_metrics): Handle `compatible widths' option.
(tt_loader_init): Handle ClearType GETINFO information bits.
* src/truetype/rules.mk (TT_DRC_SRC): Updated.
* src/truetype/ttinterp.c: Include `ttsubpix.h'.
[Where necessary, changes below are guarded by
TT_CONFIG_OPTION_SUBPIXEL_HINTING.]
(Direct_Move, Direct_Move_X): Extended.
(Round_None, Round_To_Grid, Round_To_Half_Grid, Round_Down_To_Grid,
Round_Up_To_Grid, Round_To_Double_Grid, Round_Super, Round_Super_45,
SetSuperRound): Add parameter to handle the number of grid lines per
pixel.
(SET_SuperRound, ROUND_None, CUR_Func_round): Updated.
(DO_SROUND, DOS45ROUND, DO_ODD, DO_EVEN): Updated.
(DO_ROUND, DO_NROUND): Updated.
(DO_RS): Take care of `Typeman' bytecode patterns.
(Ins_FDEF): Add some debugging code. Commented out.
(Ins_ENDF): Restore state.
(Ins_CALL, Ins_LOOPCALL): Handle inline delta functions.
(Ins_MD): Handle `Vacuform' rounds.
(Move_Zp2_Point, Ins_SHPIX, Ins_MSIRP, Ins_MDAP, Ins_MIAP,
Ins_MDRP, Ins_MIRP): Handle tweaks.
(Ins_ALIGNRP): Add tweak guard.
(Ins_IUP, Ins_DELTAP): Handle tweaks.
(Ins_GETINFO): Handle new ClearType bits.
(TT_RunIns): Handle tweaks.
* src/truetype/ttinterp.h: Updated.
(SPH_TweakRule, SPH_ScaleRule): New structures for tweaks.
(TT_ExecContextRec): Add members for subpixel hinting support.
* src/truetype/ttobjs.h (TT_DefRecord): Add `inline_delta' member.
[TT_CONFIG_OPTION_BYTECODE_INTERPRETER]: Undefine
TT_CONFIG_OPTION_UNPATENTED_HINTING. This fixes the return value of
`FT_Get_TrueType_Engine_Type' (and makes it work as documented).
Reported in bug #441638 of bugzilla.novell.com.
* docs/CHANGES: Document it.
Other minor documentation improvements.
include/freetype/config/ftconfig.h, builds/unix/ftconfig.in: Minor
beautifying.
* include/freetype/ftadvanc.h, include/freetype/ftgasp.h,
include/freetype/ftlcdfil.h: Protect against FreeType 1.
Some other minor fixes.
* devel/ftoption.h: Synchronize with
include/freetype/config/ftoption.h.
Formatting, documentation improvements.
I. IMPORTANT BUG FIXES
- Various integer overflows have been fixed.
- PFB fonts with MacOS resource fork weren't handled correctly on
non-MacOS platforms.
- The PCF font loarder has been seriously hardened against malformed
font files.
II. IMPORTANT CHANGES
- the unpatented hinter is now part of the default build of the
library, and we added code to automatically support "tricky"
fonts that need it.
what this means is that FreeType should "just work" with certain
Asian fonts, like MingLiu, which cannot properly load without a
bytecode interpreter, but fortunately do not use any of the
patented bytecode opcodes.
Note that the API didn't change, so you can still force
unpatented hinting with a special parameter to FT_Open_Face
as well.
if you're an embedded systems developer, you might want to
*disable* the feature to save code space by undefining
TT_CONFIG_OPTION_UNPATENTED_HINTING in ftoption.h.
- LCD-optimized rendering is now disabled in all default builds
of the library, mainly due to patent reasons. For more information
see:
http://lists.gnu.org/archive/html/freetype/2006-09/msg00064.html
a new configuration macro FT_CONFIG_OPTION_SUBPIXEL_RENDERING has
been introduced in ftoption.h; manually define it in this file
if you want to re-enable the feature.
the change only affects the implementation, not the FreeType API.
This means that clients don't need to be modified, because the
library still generates LCD decimated bitmaps, but with the added
constraint that R=G=B on each triplet.
- Some computation bugs in the TrueType bytecode interpreter were found,
which allow us to get rid of very subtle and rare differences we had
with the Windows renderer.
III. MISCELLANEOUS
- TrueType glyph loading is now about 25% faster.
- the anti-aliased rasterizer has been optimized and is now 15% to 25%
percent faster than the previous one, depending on content
- the Type 1 loader has been improved; as an example, it now skips
over top-level dictionaries properly
======================================================================
* src/pcf/pcfutil.c: Use FT_LOCAL_DEF.
* src/pcf/pcfutil.h: Include FT_CONFIG_CONFIG_H.
Use FT_BEGIN_HEADER and FT_END_HEADER.
Use FT_LOCAL.
2004-04-24 George Williams <gww@silcom.com>
Add support for Apple's distortable font technology (in GX fonts).
* devel/ftoption.h, include/freetype/config/ftoption.h
(TT_CONFIG_OPTION_GX_VAR_SUPPORT): New macro.
* include/freetype/ftmm.h (FT_Var_Axis, FT_Var_Named_Style,
FT_MM_Var): New structures.
(FT_Get_MM_Var, FT_Set_Var_Design_Coordinates,
FT_Set_Var_Blend_Coordinates): New function declarations.
* include/freetype/internal/services/svmm.h (FT_Get_MM_Var_Func,
FT_Set_Var_Design_Func): New typedefs.
Update MultiMasters service.
* include/freetype/internal/tttypes.h
[TT_CONFIG_OPTION_GX_VAR_SUPPORT]: Include FT_MULTIPLE_MASTERS_H.
(GX_Blend) [TT_CONFIG_OPTION_GX_VAR_SUPPORT]: New typedef.
(TT_Face) [TT_CONFIG_OPTION_GX_VAR_SUPPORT]: New members `doblend'
and `blend'.
* include/freetype/tttags.h (TTAG_avar, TTAG_cvar, TTAG_gvar): New
macros.
* include/freetype/internal/fttrace.h: Add `ttgxvar'.
* src/base/ftmm.c (FT_Get_MM_Var, FT_Set_Var_Design_Coordinates,
FT_Set_Var_Blend_Coordinates): New functions.
* src/sfnt/sfobjs.c (sfnt_load_face)
[TT_CONFIG_OPTION_GX_VAR_SUPPORT]: Set FT_FACE_FLAG_MULTIPLE_MASTERS
flag for GX var fonts.
* src/truetype/ttgxvar.c, src/truetype/ttgxvar.h: New files.
* src/truetype/truetype.c [TT_CONFIG_OPTION_GX_VAR_SUPPORT]: Include
ttgxvar.c.
* src/truetype/ttdriver.c [TT_CONFIG_OPTION_GX_VAR_SUPPORT]: Include
FT_MULTIPLE_MASTERS_H, FT_SERVICE_MULTIPLE_MASTERS_H, and ttgxvar.h.
(tt_service_gx_multi_masters) [TT_CONFIG_OPTION_GX_VAR_SUPPORT]:
New service.
(tt_services) [TT_CONFIG_OPTION_GX_VAR_SUPPORT]: Updated.
* src/truetype/ttgload.c [TT_CONFIG_OPTION_GX_VAR_SUPPORT]: Include
ttgxvar.h.
(TT_Process_Simple_Glyph, load_truetype_glyph)
[TT_CONFIG_OPTION_GX_VAR_SUPPORT] :Support GX var fonts.
* src/truetype/ttobjs.c [TT_CONFIG_OPTION_GX_VAR_SUPPORT]: Include
ttgxvar.h.
(tt_done_face) [TT_CONFIG_OPTION_GX_VAR_SUPPORT]: Call
tt_done_blend.
* src/truetype/ttpload.c [TT_CONFIG_OPTION_GX_VAR_SUPPORT]: Include
ttgxvar.h.
(tt_face_load_cvt) [TT_CONFIG_OPTION_GX_VAR_SUPPORT]: Call
tt_face_vary_cvt.
* src/truetype/rules.mk (TT_DRV_SRC): Add ttgxvar.c.
* src/type1/t1driver.c (t1_service_multi_masters): Add T1_Get_MM_Var
and T1_Set_Var_Design.
* src/type1/t1load.c (FT_INT_TO_FIXED, FT_FIXED_TO_INT): New macros.
(T1_Get_MM_Var, T1_Set_Var_Design): New functions.
* src/type1/t1load.h (T1_Get_MM_Var, T1_Set_Var_Design): New
function declarations.
* src/base/ftrfork.c, include/freetype/internal/ftrfork.h: New
files.
* src/base/ftobjs.c: Include FT_INTERNAL_RFORK_H.
(Mac_Read_POST_Resource, Mac_Read_sfnt_Resource): Remove arguments
`resource_listoffset' and `resource_data' and adapt code
accordingly. These values are calculated outside of the function
now.
Add new argument `offsets'.
(IsMacResource): Use `FT_Raccess_Get_HeaderInfo' and
`FT_Raccess_Get_DataOffsets'.
(load_face_in_embedded_rfork): New function.
(load_mac_face): Use load_face_in_embedded_rfork.
(ft_input_stream_new): Renamed to...
(FT_Stream_New): This. Use FT_BASE_DEF. Updated all callers.
(ft_input_stream_free): Renamed to...
(FT_Stream_Free): This. Use FT_BASE_DEF. Updated all callers.
* src/base/ftbase.c: Include ftrfork.c.
* src/base/rules.mk (BASE_SRC), src/base/Jamfile: Updated.
* include/freetype/internal/internal.h (FT_INTERNAL_RFORK_H):
New macro.
* include/freetype/internal/fttrace.h: Added `rfork' as a new
trace definition.
* include/freetype/internal/ftstream.h: Declare FT_Stream_New and
FT_Stream_Free.
* include/freetype/config/ftoption.h, devel/ftoption.h
(FT_CONFIG_OPTION_GUESSING_EMBEDDED_RFORK): New option.
* include/freetype/config/ftstdlib.h (ft_strrchr): New macro.
include/freetype/internal/ftobjs.h, include/freetype/internal/tttypes.h,
src/truetype/ttinterp.c, src/truetype/ttobjs.c, src/truetype/ttobjs.h:
changed the name of TT_CONFIG_OPTION_COMPILE_UNPATENTED_HINTING to
the simpler TT_CONFIG_OPTION_UNPATENTED_HINTING
removed the macro TT_CONFIG_OPTION_FORCE_UNPATENTED_HINTING. Instead,
the same effect can be used by setting a debug-hook with
FT_DEBUG_HOOK_UNPATENTED_HINTING globally with FT_Set_Debug_Hook()
. In all makefiles `/' is used as the path separator. The
conversion to the real path separators is done as late as
possible using $(subst ...).
. $(HOSTSEP) no longer exists. Now, $(SEP) gives the path separator
for the operating system, and the new $(COMPILER_SEP) the path
separator for the compiler tools.
. $(BUILD) has been renamed to $(BUILD_DIR). In general, all
directory variables end with `_DIR'. The variants ending in `_'
(like `BASE_' have been removed).
The following ChangeLog entries only describe changes which are
not related to the redesign.
* builds/beos/beos-def.mk (BUILD_DIR): Fix typo.
* builds/compiler/watcom.mk (LINK_LIBRARY): Fix linker call to avoid
overlong arguments as suggested by J. Ali Harlow
<ali@avrc.city.ac.uk>.
* builds/dos/dos-wat.mk: New file.
* builds/freetype.mk (FREETYPE_H): Include header files from the
`devel' subdirectory.
* builds/os2/os2-dev.mk, builds/unix/unixddef.mk,
builds/unix/unixddef.mk, builds/win32/w32-bccd.mk,
builds/win32/w32-dev.mk (BUILD_DIR): Fix path.
* builds/unix/configure.ac, builds/unic/configure: Updated.
* builds/unix/unix-def.in (DISTCLEAN): Add `freetype2.pc'.
* devel/ftoption.h: Updated.
Infinality