With horizontal bisections, the smallest section is a whole single
scanline. Almost horizontal lines or other complex scanlines can
easily overflow the rendering pool. Switching to vertical bisections
splits the scanlines and should rule out the overflows. Fixes#1269.
* src/smooth/ftgrays.c (gray_convert_glyph): Bisect vertically.
As a result of 7b308a29dd, the regular 64-bit execution is now faster
than SSE2. The rendering speed of script fonts at 64 ppem or larger is
improved by about 3% without SSE2. See !314 for the testing results.
* src/smooth/ftgrays.c (gray_render_conic)[FT_INT64]: Remove SSE2 code.
* src/base/ftoutln.c (FT_Outline_Reverse, FT_Outline_EmboldenXY,
FT_Outline_Get_Orientation): Set the first and last indexes together.
(FT_Outline_Decompose): Ditto and check them more stringently.
* src/smooth/ftgrays.c (FT_Outline_Decompose)[STANDALONE_]: Ditto.
Modern compilers get more insistent on that...
* include/freetype/internal/compiler-macros.h (FALL_THROUGH): Define.
* src/*: Use it instead of `/* fall through */` comments.
* src/sfnt/ttcolr.c (FT_PaintFormat_Internal): New enumeration values
`FT_COLR_PAINTFORMAT_INTERNAL_VAR_SKEW`,
`FT_COLR_PAINTFORMAT_INTERNAL_SKEW_CENTER`, and
`FT_COLR_PAINTFORMAT_INTERNAL_VAR_SKEW_CENTER`.
(read_paint): Handle new enumeration values.
Alexei Podtelezhnikov
Werner Lemberg
Jouk Jansen
Dominik Röttsches