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

[Werner LEMBERG]

>  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.