Re: Bad drawing of xft fonts overlapping box cursor

[Stephen Berman <Stephen.Berman@gmx.net>]

On Sun, 17 Feb 2008 21:47:13 +0100 bojohan+news@dd.chalmers.se (Johan Bockgård) wrote:

> In some fonts certain characters can produce overlaps with the box
> cursor.  This leads to uglily drawn characters.
>
>     emacs -Q -xrm \
>       'emacs*font: bitstream vera sans mono:pixelsize=17
>        Xft.hintstyle: hintmedium' \
>       -fg white -bg black -cr green
>
>     (progn
>       (switch-to-buffer "*test*")
>       (insert "W\nW\nW")
>       (dotimes (_ 50)
>         (redisplay)
>         (goto-char 4)
>         (redisplay)
>         (goto-char 6)))
>
> It looks like what happens is that each time the cursor is placed next
> to the problematic character another copy of the character is drawn.
> For antialiased fonts this produces the effect that the half transparent
> pixels become more and more solid.

When I try this I do not see any difference in the "W"s.  I also tried
with 500 repetitions and I magnified the screen display, but all three
characters look identical.  This is on GNU Emacs 23.0.60.5
(i686-pc-linux-gnu, GTK+ Version 2.12.0) of 2008-02-14 on escher running
under openSUSE 10.3.

Steve Berman