This patch allows Blender to display i18n monospace font in the text
editor and the Python interactive console. Wide characters that occupy
multiple columns such as CJK characters can be displayed correctly.
Furthermore, wrapping, selection, suggestion, cursor drawing, and
syntax highlighting should work.
Also fixes a bug [#34543]: In Text Editor false color in comment on cyrillic
To estimate how many columns each character occupies, this patch uses
wcwidth.c written by Markus Kuhn and distributed under MIT-style license:
http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
wcwidth.c is stored in extern/wcwidth and used as a static library.
This patch adds new API to blenfont, blenlib and blenkernel:
BLF_get_unifont_mono()
BLF_free_unifont_mono()
BLF_draw_mono()
BLI_wcwidth()
BLI_wcswidth()
BLI_str_utf8_char_width()
BLI_str_utf8_char_width_safe()
txt_utf8_offset_to_column()
txt_utf8_column_to_offset()
