Re: Patch for Mac OS X Text Drawing

[YAMAMOTO Mitsuharu]

>>>>> On Fri, 21 Jan 2005 21:52:55 -0500, Richard Stallman <address@hidden> 
>>>>> said:

> It seems strange that a Mac-only bug would need system-independent
> changes.  Why is that?

Because the current (system-independent) code assumes that drawing the
same character over the existing one does not change its appearance,
but that's not true on Mac OS X with text anti-aliasing.

Quote from http://developer.apple.com/qa/qa2001/qa1193.html:

  Avoid double-drawing the same text because anti-aliased areas darken
  with repeated over-drawing.

I'm not sure about other environments with anti-aliasing such as Xft
and ClearType.  Does anyone know about how over-drawing is treated
there?

                                     YAMAMOTO Mitsuharu
                                address@hidden