Back in the days, vector length calculations were not very accurate
and the vector normalization function, Normalize, had to meticulously
correct the errors for long vectors [commit b7ef2b096867]. It was no
longer necessary after accurate CORDIC algorithms were adopted, but
the code remained. It is time to kill it.
* src/truetype/ttinterp.c (Normalize): Remove error compensation.
(TT_VecLen): Remove any mention of old less accurate implementation.
* include/freetype/internal/ftserv.h (FT_SERVICE_UNAVAILABLE): Use
`logical not' operator instead of negation. The idea is that `~'
returns exactly the data type enforced by the cast to a pointer (be
it 32bit or 64bit or whatever), while a negative integer has not
this flexibility.
* src/cache/ftccmap.c (FTC_CMAP_UNKNOWN): Ditto.
* src/truetype/ttgxvar.c (ALL_POINTS, TT_Get_MM_Var): Ditto.
* src/type/t1load.c (T1_Get_MM_Var): Ditto.
(parse_blend_axis_types): Use cast.
* src/bdf/bdflib.c (_bdf_readstream): Use cast.
The dot product between freeVector and projVector or cosine of
the angle between these FT_F2Dot14 unit vectors used to be scaled up
by 4 and routinely occupied 32 bits in an FT_Long field F_dot_P.
This patch scales the value down by 2^14 instead, which simplifies
its use throughout the bytecode interpreter.
This does not lead to the loss of precision because the lower bits
are unreliable anyway. Consider two unit vectors (1,0) and (.6,.8)
for which the true value of F_dot_P is .6 * 0x40000000 = 0x26666666.
These vectors are stored as (0x4000,0) and (0x2666,0x3333) after
rounding and F_dot_P is assigned 0x26660000. The lower bits were
already lost while rounding the unit vector components.
Besides code simplification, this change can lead to better
performance when FT_MulDiv with the scaled-down F_dot_P is less
likely to use the costly 64-bit path. We are not changing the type
of F_dot_P to FT_F2Dot14 at this point.
* src/truetype/ttinterp.c (Compute_Funcs): Scale F_dot_P down by 14
bits and modify its use accordingly.
(Direct_Move, Direct_Move_Orig, Compute_Point_Displacement): Modify
the use of F_dot_P field.
* src/truetype/ttobjs.c (tt_size_run_fpgm): Change arbitrary
assignment of F_dot_P to its theoretical maximum in case we decide
to scale back its type later.
* src/truetype/ttinterp.c (TT_DivFix14): New macro.
(Normalize): Use it here.
(Current_Ratio): Use TT_MulFix14 instead of FT_MulDiv.
(Ins_SHPIX): Cancel out two TT_MulFix14 calls.
* src/truetype/ttinterp.c (Ins_ISECT): Use angle between vectors to
avoid grazing intersections. The previous threshold was too coarse,
incorrectly rejecting short but valid vectors.
* include/freetype/internal/ftcalc.h (FT_MulDiv_No_Round): Don't
enclose with `TT_USE_BYTECODE_INTERPRETER'; we now need the function
elsewhere also.
* src/autofit/afcjk.h: Use AF_CONFIG_OPTION_CJK.
* src/truetype/ttgload.c (tt_loader_init): Fix compiler warning.
* src/truetype/ttinterp.c (Ins_MSIRP): Fix compiler warning.
* src/truetype/ttinterp.h: Use
TT_CONFIG_OPTION_BYTECODE_INTERPRETER.
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.
NEC FA family dated in 1996 have different checksum.
Reported by Johnson Y. Yan <yinsen_yan@foxitsoftware.com>; see
http://lists.gnu.org/archive/html/freetype-devel/2012-06/msg00023.html
* src/truetype/ttobjs.c (tt_check_trickyness_sfnt_ids): 4 sets
of fpgm & prep table checksums for FA-Gothic, FA-Minchou,
FA-RoundedGothicM, FA-RoundedGothicB are added. The family
names in sample PDF are truncated, thus the list of the
family names in tt_check_trickyness_family() is not updated yet.
* src/truetype/ttinterp.c (DO_SSW): SSW *does* use font units. For
verification, it took some time to find a font which actually uses
this instruction.
* src/truetype/ttinterp.c (Ins_MIRP): Typo, present since ages. The
code is now in sync with the other operators (e.g. MSIRP) which
modify twilight points.
Jump instructions are now bound to the current function. The MS
Windows rasterizer behaves the same, as confirmed by Greg Hitchcock.
* src/truetype/ttinterp.h (TT_CallRec): Add `Cur_End' element.
* src/truetype/ttobjs.h (TT_DefRecord): Add `end' element.
* src/truetype/ttinterp.c (DO_JROT, DO_JMPR, DO_JROF): Check upper
bound of jump address.
(Ins_FDEF, Ins_CALL, Ins_LOOPCALL, Ins_UNKNOWN, TT_RunIns): Updated.
Originally FT_DEFINE_{DRIVER,MODULE,RENDERER}() macros were
designed to declare xxx_pic_{free,init} by themselves.
Because these macros are used at the end of the module
interface (e.g. ttdriver.c) and the wrapper source to build
a module as a single object (e.g. truetype.c) includes
the PIC file (e.g. ttpic.c) before the module interface,
these macros are expanded AFTER xxx_pic_{free,init} body
when the modules are built as single object.
The declaration after the implementation causes the redundant
declaration warnings, so the declarations are moved to module
PIC headers (e.g. ttpic.h). Separating to other header files
are needed for multi build.
* include/freetype/internal/ftdriver.h (FT_DEFINE_DRIVER):
Remove class_##_pic_free and class_##_pic_init declarations.
* include/freetype/internal/ftobjs.h (FT_DEFINE_RENDERER,
FT_DEFINE_MODULE): Ditto.
* src/base/basepic.h: Insert a comment and fix coding style.
* src/autofit/afpic.h: Declare autofit_module_class_pic_{free,
init}.
* src/cff/cffpic.h: Declare cff_driver_class_pic_{free,init}.
* src/pshinter/pshpic.h: Declare pshinter_module_class_pic_{free,
init}.
* src/psnames/pspic.h: Declare psnames_module_class_pic_{free,
init}.
* src/raster/rastpic.h: Declare
ft_raster{1,5}_renderer_class_pic_{free,init}
* src/sfnt/sfntpic.h: Declare sfnt_module_class_pic_{free,init}.
* src/smooth/ftspic.h: Declare
ft_smooth_{,lcd_,lcdv_}renderer_class_pic_{free,init}.
* src/truetype/ttpic.h: Declare tt_driver_class_pic_{free,init}.
Under PIC configuration, FT_{CFF,PSCMAPS,SFNT,TT}_SERVICES_GET
take no arguments but derefer the variable named `library'
internally.
* src/cff/cffdrivr.c (cff_get_interface): Declare `library' and
set it if non-NULL driver is passed.
* src/truetype/ttdriver.c (tt_get_interface): Ditto.
* src/sfnt/sfdriver.c (sfnt_get_interface): Declare `library'
under PIC configuration, and set it if non-NULL module is given.
* src/psnames/psmodule.c (psnames_get_interface): Ditto.
error codes with per-module prefix.
* src/autofit/afpic.c: Include `aferrors.h'.
* src/cff/cffpic.c: Include `cfferrs.h'.
* src/pshinter/pshpic.c: Include `pshnterr.h'.
* src/raster/rastpic.c: Include `rasterrs.h'.
* src/sfnt/sfntpic.c: Include `sferrors.h'.
* src/smooth/ftspic.c: Include `ftsmerrs.h'.
* src/truetype/ttpic.c: Include `tterrors.h'.
