[sfnt] Implement PS names for font instances [3/3].
Everything is guarded with TT_CONFIG_OPTION_GX_VAR_SUPPORT.
* include/freetype/internal/tttypes.h (TT_FaceRec): New fields
`var_postscript_prefix' and `var_postscript_prefix_len'.
* src/sfnt/sfdriver.c: Include FT_TRUETYPE_IDS_H.
(sfnt_is_alphanumeric): New wrapperfunction for `ft_isalnum'.
(get_win_string, get_apple_string): Remove `const' from return
value.
(MAX_VALUE_DESCRIPTOR_LEN, MAX_PS_NAME_LEN): New macros.
(hexdigits): New array.
(sfnt_get_var_ps_name): New function, implementing Adobe TechNote
5902 to construct a PS name for a variation font instance.
(sfnt_get_ps_name): Call `sfnt_get_var_ps_name' for font instances.
* src/sfnt/sfobjs.c (sfnt_done_face): Updated.
* src/truetype/ttgxvar.c (tt_set_mm_blend): Reset
`face->postscript_name' to trigger recalculation for new instance
parameters.
6 files changed
