It's unused after the following commits:
[raster] Allocate render pool for mono rasterizer on the stack.
[raster] Remove 5-level gray AA mode from monochrome rasterizer.
The value of FT_RENDER_POOL_SIZE still serves the purpose it used to
serve, which is, to adjust the pool size. But the pool is now
allocated on the stack on demand.
* src/base/ftobjs.c (FT_New_Library, FT_Done_Library): Implement.
Instead of keeping `library->renderers' in a MRU order, just leave
it as-is. The MRU machinery wasn't thread-safe.
With this patch, rasterizing glyphs from different faces from
different threads doesn't fail choosing rasterizer
(FT_Err_Cannot_Render_Glyph).
Easiest to see that crash was to add a `printf' (or otherwise let
thread yield in FT_Throw with debugging enabled).
* src/base/ftobjs.c (FT_Render_Glyph_Internal), src/base/ftoutln.c
(FT_Outline_Render): Don't call `FT_Set_Renderer'.
Assure that FreeType's internal include directories are found before
`CPPFLAGS' (which might be set by the user in the environment), and
`CPPFLAGS' before `CFLAGS'.
* builds/freetype.mk (FT_CFLAGS): Don't add `INCLUDE_FLAGS'.
(FT_COMPILE): Make this a special variable for compiling only the
files handled in `freetype.mk'.
(.c.$O): Removed, unused.
* src/*/rules.mk (*_COMPILE): Fix order of include directories.
All public FreeType enumeration and flag values are uppercase...
* include/tttables.h (FT_Sfnt_Tag): Implement it. For backwards
compatilibity, retain the old values as macros.
* src/base/ftfstype.c (FT_Get_FSType_Flags), src/sfnt/sfdriver.c
(get_sfnt_table): Updated.
`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.
The scaling between the hypotenuse and its CORDIC approximation is
based on regression analysis. The smaller padding for `theta' is
justifed by its maximum error of less than 6.
* src/base/fttrigon.c (ft_trig_downscale): Borrow code from
./ftcalc.c (ft_multo64), change linear intercept.
(ft_trig_pseudo_polarize): Decrease `theta' padding.
* include/internal/ftcalc.h (FT_HYPOT): Macro to approximate Euclidean
distance with the alpha max plus beta min algorithm.
* src/base/ftcalc.c (ft_corner_is_flat): Use it instead of Taxicab metric.
We shift as many bits as we can into the high register, perform
32-bit division with modulo there, then work through the remaining
bits with long division. This optimization is especially noticeable
for smaller dividends that barely use the high register.
* src/base/ftcalc.c (ft_div64by32): Updated.
Werner Lemberg