Bunch of patches that 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, and cursor drawing should work.

Screenshot: https://plus.google.com/photos/108666457756457924138/albums/5847890778201826545/5847890782374975970?authkey=CIPZrc32pPzuTw

This patch uses wcwidth.c written by Markus Kuhn to estimate how many columns each character occupies:

http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c

wcwidth.c is distributed under MIT-style license:

Permission to use, copy, modify, and distribute this software
for any purpose and without fee is hereby granted. The author
disclaims all warranties with regard to this software.


I attached 3 files:

- texteditor_console_i18n.tar.gz ... Patch files (See below for details)
- texteditor_console_i18n.patch ... Same as .tar.gz file, but unified all patches into one file
- WenQuanYiMicroHeiMono.ttf.gz ... Font file for testing CJK characters display


The tgz archive texteditor_console_i18n.tar.gz contains 7 patches:

(0) 00_i18n_mono_font.patch

Patch to load i18n monospace font when "International Fonts" in user preference is ON.
Adds function to blenfont:

BLF_get_unifont_mono()
BLF_free_unifont_mono()

(1) 10_extern_wcwidth.patch

Integrates wcwidth.c into extern/wcwidth/ directory. I made wcwidth.h to use it as a library.

(2) 20_BLI_str_utf8_char_width.patch

Adds primitive functions to blenlib to use wcwidth.c:

BLI_wcwidth()
BLI_wcswidth()
BLI_str_utf8_char_width()
BLI_str_utf8_char_width_safe()

Also adds BLI_UTF8_WIDTH_MAX macro. Its value is 2 (in columns).

(3) 30_BLF_draw_mono.patch

Adds a function BLF_draw_mono() to blenfont. This is an analogue of BLF_draw() but drows texts with fixed column width. It takes additional the 4th argument 'cwidth', and returns how many columns were used.

(4) 40_BKE_txt_utf8_offset_to_column.patch

Adds functions txt_utf8_offset_to_column() and txt_utf8_column_to_offset() to blenkernel. They are alternatives of txt_utf8_offset_to_index() and txt_utf8_index_to_offset(), respectively.
Also modifies txt_move_up() and txt_move_down() to take character widths into account.

(5) 50_space_text_i18n.patch

Fixes the text editor (space_text) to take character widths into account.
Renames some internal functions to more suitable names:

txt_utf8_get_nth() -> txt_utf8_forward_columns()
text_pixel_x_to_index() -> text_pixel_x_to_column()
flatten_len() -> flatten_width()
flatten_index_to_offset() -> flatten_column_to_offset()

Also changes args/retval of some inernal functions.

(6) 60_space_console_i18n.patch

Fixes the interactive console (space_console + space_info) to take character widths into account.
Adds internal functions to compute offsets for wrapping:

console_wrap_offsets()
console_cursor_wrap_offset()

Also changes args/retval of some inernal functions.


To build blender with the patch, apply the above 7 patches or texteditor_console_i18n.patch, and save the font file into release/datafiles/fonts/ directory.


Note 1: WenQuanYi Micro Hei font is used only for testing. We should prepare more appropriate one, because the WQY font doesn't include all languages' characters which Blender supports. If you want to test the patch with the other font, save it as "WenQuanYiMicroHeiMono.ttf.gz" (file name is hard-coded). For example, to use DejaVu Sans Mono font on Ubuntu,

gzip -c9 /usr/share/fonts/truetype/ttf-dejavu/DejaVuSansMono.ttf > [PATH_TO_SOURCE_TREE]/release/datafiles/fonts/WenQuanYiMicroHeiMono.ttf.gz


Note 2: I'm testing it only on Ubuntu 12.10 (with both CMake and SCons), not tested on Win/Mac at all.