Re: A patch for enforcing double-width CJK character display

[黄建忠]

Hi, Miles.

I tried "Lucida Sans Typewriter" font,  It seems Emacs git head(without 
cjk patch) had some problems to rendering this font.
See the attachment as reference.

Comparing to normal GTK applications(cairo rendering backend),  it's too 
wide in Emacs.

I am not sure the problem is related to Emacs or libXft now, but it is a 
BUG.

My envs:
libXft-2.3.0 without patch.
fontconfig-2.8.0 without patch.
Freetype-2.4.9 with infinality rendering patchset.


于 2012年04月17日 12:56, Werner LEMBERG 写道:
> >   1) In case 1, a 20-character sequence of ASCII characters takes 180
> >      pixels to display, and a 10-character sequence of CJK characters
> >      takes 120 pixels to display.
> Mhmm.  The silent assumption of making a CJK and ASCII font fit is
> that double-width characters are really double width in relation to
> single-width characters.  In your example, the width of two ASCII
> characters is 18px, while one CJK character is 12px.  Such two fonts
> simply don't fit, and no clever algorithm will be able to make them
> ever fit without scaling.[1] Your arguments are thus moot IMHO.
>
>
>      Werner
>
>
> [1] Not counting a full analysis of all glyphs of a font to check
>      whether it is possible to compress the advance width horizontally
>      because the left and right side bearings are large enough to do
>      that without overlapping.


--
Huang JianZhong

lucida.jpg
Description: JPEG image