This is a follow-up patch.
* src/truetype/ttinterp.c, src/truetype/ttinterp.h
[TT_CONFIG_OPTION_STATIC_INTERPRETER,
TT_CONFIG_OPTION_STATIC_RASTER]: Remove macros and related code.
`API functions' are functions tagged with `FT_EXPORT_DEF'.
Besides trivial fixes, the following changes are included, too.
* src/base/ftbdf.c (FT_Get_BDF_Charset_ID, FT_Get_BDF_Property): Set
error code if no service is available.
* src/base/ftinit.c (FT_Done_FreeType): Change return value for
invalid `library' parameter to `Invalid_Library_Handle'.
* src/base/ftobjs.c (FT_New_Size): Change return value for invalid
`asize' parameter to `Invalid_Argument'.
* src/base/ftoutln.c (FT_Outline_Copy): Change return value for
invalid `source' and `target' parameters to `Invalid_Outline'.
(FT_Outline_Done_Internal): Change return value for invalid
`outline' parameter to `Invalid_Outline'.
The functions in this patch *do* return non-trivial errors that must
be taken care of.
* src/autofit/afloader.c (af_loader_load_g), src/base/ftobjs.c
(FT_Render_Glyph_Internal), src/base/ftoutln.c (FT_Outline_Render),
src/cff/cffgload.c (cff_decoder_parse_charstrings) <cff_op_endchar>,
src/psaux/psobjs.c (ps_parser_load_field_table), src/psaux/t1decode
(t1_decoder_parse_charstrings) <op_endchar>, src/truetype/ttgload.c
(load_truetype_glyph <subglyph loop>, tt_loader_init,
TT_Load_Glyph), src/truetype/ttgxvar.c (TT_Set_MM_Blend),
src/truetype/ttobjs.c (tt_size_run_fpgm, tt_size_run_prep): Do it.
We use a cast to indicate that we intentionally ignore a function's
return value. However, this doesn't apply to API functions where
errors can only happen for trivially invalid input.
* src/base/ftstroke.c (FT_Glyph_Stroke, FT_Glyph_StrokeBorder),
src/base/ftsynth.c (FT_GlyphSlot_Embolden), src/cff/cffgload.c
(cff_slot_load), src/pfr/pfrdrivr.c (pfr_get_kerning),
src/type1/t1load.c (parse_encoding), src/type42/t42parse.c
(t42_parse_encoding): Do it.
Before this patch, it was impossible to ever call DELTAP[123] in
subpixel hinting mode as described in the ClearType whitepaper; it
only worked if in `compatibility mode'. However, compatibility mode
essentially disables SHPIX, completely ruining hinting of
ttfautohint output, for example.
We now follow the whitepaper more closely so that DELTAP[123]
instructions for touched points in the non-subpixel direction are
executed.
Zero distance does not have to be treated specially if you follow
specifications and check the sign as the very last step of rounding.
* src/truetype/ttinterp.c (Round_None, Round_To_Grid,
Round_Down_To_Grid, Round_Up_To_Grid, Round_To_Double_Grid): Use
macros when available, do not check for non-zero distance.
(Round_To_Half_Grid, Round_Super, Round_Super_45): Ditto, return phase
if sign changed.
Suggested by Doug Felt <dougfelt@gmail.com>.
* src/sfnt/ttsbit.c (tt_sbit_decoder_load_metrics): Set
`vertAdvance' to zero...
* src/truetype/ttgload.c (TT_Load_Glyph): ... and set here a default
value for `vertAdvance' based on `linearVertAdvance' in case
`vertAdvance' is zero. Note that the previous computed ad-hoc value
for `linearVertAdvance' was apparently not tested in a real-life
situation.
The legal range for delta shift is zero through six. Negative values
are illegal according to
https://developer.apple.com/fonts/TrueType-Reference-Manual/RM04/Chap4.html#delta%20shift
* src/truetype/ttobjs.h (delta_shift, delta_base): Make unsigned.
* src/truetype/ttinterp.h (DO_SDS): Throw an error if delta_shift
out of range.
(Ins_DELTAP, Ins_DELTAC): Optimize for legal delta_shift.
* src/truetype/ttinterp.h (TT_ExecContextRec): New field
`cur_ppem_func' with a function pointer.
* src/truetype/ttinterp.c (TT_RunIns): Initialize `cur_ppem_func'
depending on the pixel geometry to either...
(Current_Ppem_Stretched): ... this for stretched pixels.
(Current_Ppem): ... or this for square pixels.
(DO_MPPEM, DO_MPS, Ins_DELTAP, Ins_DELTAC): Use `cur_ppem_func'.
In case of an error in the `prep' table, no longer try to execute it
again and again. This makes FreeType handle endless loops in buggy
fonts much faster.
* src/truetype/ttobjs.h (TT_SizeRec): The fields `bytecode_ready'
and `cvt_ready' are now negative if not initialized yet, otherwise
they indicate the error code of the last run.
* src/truetype/ttobjs.c (tt_size_run_fpgm, tt_size_run_prep,
tt_size_done_bytecode, tt_size_init_bytecode,
tt_size_ready_bytecode, tt_size_init, tt_size_done, tt_size_reset):
Updated.
* src/truetype/ttgload.c (tt_loader_init): Updated.
* src/truetype/ttinterp.c (TT_RunIns): Force reexecution of `fpgm'
and `prep' only if we are in the `glyf' table.
This patch unifies the subpixel and non-subpixel cases.
* src/truetype/ttinterp.h (TT_ExecContextRec): Remove
`grayscale_hinting'; all code should refer to `grayscale' instead.
Remove unused `native_hinting' member.
Rename `subpixel_hinting' member to `subpixel.
* src/truetype/ttgload.c (TT_LOADER_SET_PP): Updated.
(tt_loader_init): Updated.
* src/truetype/ttinterp.c (Ins_GETINFO): Simplify.
Updated.
Problem reported by Nigel Tao <nigeltao@golang.org>.
* src/truetype/ttgload.c (TT_Hint_Glyph): Remove code that shifts
the glyph (component) by a fractional value computed from the LSB
phantom point. This is wrong, since the horizontal phantom points
get rounded horizontally later on.
Greg Hitchcock provided very interesting insights into the
complicated history of the horizontal positions of the TSB and BSB
phantom points.
* src/truetype/ttgload.c (TT_LOADER_SET_PP)
[TT_CONFIG_OPTION_SUBPIXEL_HINTING]: Use `subpixel_hinting' and
`grayscale_hinting' flags as conditionals for the x position of TSB
and BSB.
This is a further improvement to the changes from 2013-11-06.
* src/truetype/ttgload.c (TT_Hint_Glyph): Horizontal phantom points
are rounded horizontally, vertical ones are rounded vertically.
(TT_LOADER_SET_PP): The horizontal position of vertical phantom
points in pre-ClearType mode is zero, as shown in the OpenType
specification.
Problem reported by Akira Kakuto <kakuto@fuk.kindai.ac.jp>.
* src/truetype/ttgload.c (TT_Load_Simple_Glyph): Protect call to
`Update_Max' with both a TT_USE_BYTECODE_INTERPRETER guard and a
`IS_HINTED' clause.
Also remove redundant check using `maxSizeOfInstructions' – in
simple glyphs, the bytecode data comes before the outline data, and
a validity test for this is already present.
Problem reported by Hin-Tak Leung <htl10@users.sourceforge.net>; see
http://lists.nongnu.org/archive/html/freetype-devel/2013-08/msg00005.html
for details.
* src/base/ftobjs.c (FT_Load_Glyph): Check size of `fpgm' and `prep'
tables also for setting `autohint'.
* src/truetype/ttgload.c (TT_Load_Simple_Glyph): Use code from
`TT_Process_Composite_Glyph' for handling unreliable values of
`maxSizeOfInstructions'.
Problem reported by Nigel Tao <nigeltao@golang.org>.
This is a follow-up commit to the previous one.
* src/truetype/ttgload.c (load_truetype_glyph): Call
`tt_get_metrics' after loading the glyph header.
This commit also improves the start values of vertical phantom
points. Kudos to Greg Hitchcock for help.
* src/truetype/ttgload.c (TT_Get_VMetrics): Add parameter to pass
`yMax' value. Replace code with fixed Microsoft definition.
(tt_get_metrics): Updated.
(TT_LOADER_SET_PP): Add explanation how to initialize phantom
points, taken from both the OpenType specification and private
communication with Greg (which will eventually be added to the
standard).
Fix horizontal position of `pp3' and `pp4'.
* src/truetype/ttgload.h: Updated.
* src/truetype/ttdriver.c (tt_get_advances): Updated.
* docs/CHANGES: Updated.
Two benefits: The allocated FDEF (and IDEF) array gets slightly
smaller, and the `ttdebug' demo program has access to function
numbers without additional costs.
Fortunately, no changes to FontForge are necessary – this is the
only external TrueType debugger I know of, but others may exist and
should check the code accordingly.
* src/truetype/ttinterp.h (TT_CallRec): Replace `Cur_Restart' and
`Cur_End' with a pointer to the corresponding `TT_DefRecord'
structure.
* src/truetype/ttinterp.c (DO_JROT, DO_JMPR, DO_JROF, Ins_ENDF,
Ins_CALL, Ins_LOOPCALL, Ins_UNKNOWN, TT_RunIns <Invalid_Opcode>):
Updated.
When using `ADD' with an immediate operand, the instruction is
actually `ADD Rd, Rn, #<imm12>', that is, the maximum of the
immediate operand cannot exceed 4095. It will fail to compile with
LLVM.
However, in GCC, due to some legacy compatibility considerations,
`ADD.W' will be automatically emitted when the immediate operand is
larger than 4095.
* builds/unix/ftconfig.in, include/freetype/config/ftconfig.h
(FT_MulFix_arm) [__GNUC__]: Support clang compiler.
* src/truetype/ttinterp.c (TT_MulFix14_arm) [__GNUC__]: Ditto.
