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.
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.
`load_strike_metrics' used to load the strike's metrics.
* src/sfnt/sfdriver.c, src/sfnt/ttsbit.c, src/sfnt/ttsbit.h,
src/sfnt/ttsbit0.c: New function `tt_face_load_strike_metrics'.
* src/pfr/pfrobjs.c (pfr_face_init): Set FT_Bitmap_Size correctly.
* src/winfonts/winfnt.c (FNT_Face_Init): Use `nominal_point_size' for
nominal size unless it is obviously incorrect.
* include/freetype/freetype.h (FT_Bitmap_Size): Update the comments on
FNT driver.
Introduce new size selection interface.
* include/freetype/internal/ftdriver.h (struct FT_Driver_ClassRec_):
Replace `set_char_sizes' and `set_pixel_sizes' by `request_size' and
`select_size'.
* include/freetype/freetype.h (FT_Select_Size, FT_Size_Request_Type,
FT_Size_Request, FT_Request_Size, FT_Select_Size), src/base/ftobjs.c
(FT_Select_Size, FT_Request_Size): API additions to export the new
size selection interface.
* src/base/ftobjs.c (FT_Set_Char_Size, FT_Set_Pixel_Sizes): Use
`FT_Request_Size'.
* include/freetype/internal/ftobjs.h (FT_Match_Size),
src/base/ftobjs.c (FT_Match_Size): New function to match a size
request against `available_sizes'. Drivers supporting bitmap strikes
can use this function to implement `request_size'.
* src/bdf/bdfdrivr.c, src/cid/cidobjs.c, src/cid/cidobjs.h,
src/cid/cidriver.c, src/pcf/pcfdrivr.c, src/type1/t1driver.c,
src/type1/t1objs.c, src/type1/t1objs.h, src/type42/t42drivr.c,
src/type42/t42objs.c, src/type42/t42objs.h, src/winfonts/winfnt.c:
Update to new size selection interface.
* src/cff/cffdrivr.c, src/cff/cffgload.c, src/cff/cffobjs.c,
src/cff/cffobjs.h, src/truetype/ttdriver.c, src/truetype/ttgload.c,
src/truetype/ttobjs.c, src/truetype/ttobjs.h: Update to new size
selection interface.
Make `strike_index' FT_ULong and always defined.
Use `load_strike_metrics' provided by SFNT interface.
TT_Done_Context and rename TT_Destroy_Context to TT_Done_Context with
slight changes.
* src/truetype/ttobjs.h (tt_slot_init): New function.
* src/truetype/ttobjs.c (tt_driver_init): Initialize execution context
here.
(tt_slot_init): New function to create extra points for the internal
glyph loader. We then use it directly, instead of face's glyph loader,
when loading glyph.
* src/truetype/ttdriver.c: Use tt_slot_init for glyph slot
initialization.
(TT_Load_Glyph): Load flag dependencies are handled here.
Return error if size is NULL.
* src/truetype/ttgload.c: Heavy cleanup and refactor.
(TT_Hint_Glyph): New funcion to hint a zone, prepared by caller.
(TT_Process_Simple_Glyph): Use loader->pp's instead of recalculating.
Use TT_Hint_Glyph.
No need to save/restore loader->stream before/after
TT_Vary_Get_Glyph_Deltas now.
(TT_LOADER_SET_PP): New macro to calculate and set the four phantom points.
(TT_Process_Composite_Component, TT_Process_Composite_Glyph,
load_truetype_glyph): Refactor load_truetype_glyph into these three functions.
Never set exec->glyphSize to 0. (close#13107)
Forget glyph frame before calling TT_Process_Simple_Glyph.
(TT_Load_Glyph, load_sbit_image, tt_loader_init): Refactor TT_Load_Glyph into
these three functions.
Set various fields of `glyph' here, instead of in load_truetype_glyph
and compute_glyph_metrics.
* src/truetype/ttobjs.c (tt_size_run_fpgm, tt_size_run_prep): New functions.
(tt_size_init): Add 4, instead of 2, (phantom) points to twilight zone.
Move code that runs fpgm to tt_size_run_fpgm.
(Reset_Outline_Size): Move code that runs prep to tt_size_run_prep.
(tt_glyphzone_new): Allocate right size of arrays.
Set max_points and max_contours properly.
tt_face_done, tt_size_init, tt_size_done, tt_driver_init,
tt_driver_done): Don't use TT_XXX but FT_XXX arguments which are
typecast to the proper TT_XXX within the function.
Update code accordingly.
* src/truetype/ttdriver.c (Get_Kerning, Set_Char_Sizes,
Set_Pixel_Sizes, Load_Glyph, tt_get_interface): Don't use TT_XXX but
FT_XXX arguments which are typecast to the proper TT_XXX within the
function.
Update code accordingly.
(tt_driver_class): Remove casts.
* include/freetype/internal/tttypes.h (TT_LoaderRec): Add
`top_bearing', `vadvance', `pp3, and `pp4'.
* src/autofit/afloader.c (af_loader_load_g): Handle two more points.
* src/autohint/ahhint.c (ah_hinter_load): Handle two more points.
* src/truetype/ttgload.c (Get_VMetrics): New function.
(TT_Load_Simple_Glyph, TT_Process_Simple_Glyph): Handle two more
points.
(load_truetype_glyph): Use Get_VMetrics.
Handle two more points.
(compute_glyph_metrics): Thanks to vertical phantom points we now
can always compute `advance_height' and `top_bearing'.
* src/truetype/ttobjs.h (TT_SubglyphRec): Add vertical phantom
points.
* src/autohint/ahglyph.c (ah_outline_load): Fix allocation of
`news'.
Converting some files to Unix end-of-line convention.
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()
want to list them all here. The operations performed were all logical
transformations of the sources:
- trying to convert all enums and constants to CAPITALIZED_STYLE, with
#define definitions like
#define my_old_constants MY_NEW_CONSTANT
- big, big update of the documentation comments
* include/freetype/freetype.h, src/base/ftobjs.c, src/smooth/ftsmooth.c,
include/freetype/ftimage.h: adding support for LCD-optimized rendering
though the new constants/enums:
FT_RENDER_MODE_LCD, FT_RENDER_MODE_LCD_V
FT_PIXEL_MODE_LCD, FT_PIXEL_MODE_LCD_V
this is still work in progress, don't expect everything to work correctly
though most of the features have been implemented.
* adding new FT_LOAD_XXX flags, used to specify both hinting and rendering
targets:
FT_LOAD_TARGET_NORMAL :: anti-aliased hinting & rendering
FT_LOAD_TARGET_MONO :: monochrome bitmaps
FT_LOAD_TARGET_LCD :: horizontal RGB/BGR decimated hinting & rendering
FT_LOAD_TARGET_LCD_V :: vertical RGB/BGR decimated hinting & rendering
note that FT_LOAD_TARGET_NORMAL is 0, which means that the default
behaviour of the font engine is _unchanged_.
details.
* include/freetype/internal/cfferrs.h,
include/freetype/internal/tterrors.h,
include/freetype/internal/t1errors.h: Removed. Replaced with files
local to the module. All extra error codes have been moved to
`fterrors.h'.
* src/sfnt/ttpost.h: Move error codes to `fterrors.h'.
* src/autohint/aherrors.h, src/cache/ftcerror.h, src/cff/cfferrs.h,
src/cid/ciderrs.h, src/pcf/pcferror.h, src/psaux/psauxerr.h,
src/psnames/psnamerr.h, src/raster/rasterrs.h, src/sfnt/sferrors.h,
src/smooth/ftsmerrs.h, src/truetype/tterrors.h,
src/type1/t1errors.h, src/winfonts/fnterrs.h: New files defining the
error names for the module it belongs to.
* include/freetype/ftmoderr.h: New file, defining the module error
offsets. Its structure is similar to `fterrors.h'.
* include/freetype/fterrors.h (FT_NOERRORDEF): New macro.
(FT_ERRORDEF): Redefined to use module error offsets.
All internal error codes are now public; unused error codes have
been removed, some are new.
* include/freetype/config/ftheader.h (FT_MODULE_ERRORS_H): New
macro.
* include/freetype/config/ftoption.h
(FT_CONFIG_OPTION_USE_MODULE_ERRORS): New macro.
All other source files have been updated to use the new error codes;
some already existing (internal) error codes local to a module have
been renamed to give them the same name as in the base module.
All make files have been updated to include the local error files.
* src/cid/cidtokens.h: Replaced with...
* src/cid/cidtoken.h: This file for 8+3 consistency.
* src/raster/ftraster.c: Use macros for header file names.
`__' (those which haven't converted yet). Fixed minor conversion
issues.
* src/winfonts/winfnt.c: Updated to new header inclusion scheme.
* */*.[ch]: Changed source files to adhere to the new
* src/cff/cff.c, src/cff/rules.mk: Updated.
* */*.[ch]: Now using <ft2build.h> as the default build and setup
I've made a few modifications:
- there is no new field named "driver" in "FT_SizeRec"
- the new fields in "TT_SizeRec" are:
strike_index :: value 0xFFFF means "no sbit strike selected"
strike_metrics :: the FT_Size_Metrics structure corresponding to
the currently selected strike
- the code in "ttload.c" has been somewhat cleaned up too
thanks a lot, Y-U !!
- David
Now unix.in uses absolute paths also to overcome problems with libtool.
To do that in a consistent way I had to modify the rules how to handle
$OBJ_DIR (and consequently $LIB_DIR): You should set $OBJ_DIR explicitly
on the command line (or environment).
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.
The 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 had 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 WHEN 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 WHEN 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.
rid of most of the basic types redefinitions (i.e. FT_Int instead
of "FT_Int", etc..)
The format-specific prefixs like "TT_", "T1_", "T2_" & 'CID_"
are now only used in relevant structures..
fixed Werner's fix to t2gload.c :-)
other small bug fixes
