GNU bug report logs -
#15555
24.3; Bidirectional display very slow with long lines
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Reported by: Jerome L Quinn <jlquinn <at> us.ibm.com>
Date: Mon, 7 Oct 2013 20:25:01 UTC
Severity: normal
Merged with 3219,
4123,
9589,
13675,
18530,
22143,
24523,
30457,
32523,
40007
Found in versions 23.1, 24.2, 24.2.93, 24.3, 24.5, 26.0.91, 27.0.50, 28.0.50
Fixed in version 29.1
Done: Lars Ingebrigtsen <larsi <at> gnus.org>
Bug is archived. No further changes may be made.
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On 02/18/2014 09:42 PM, Eli Zaretskii wrote:
> Anyway, just moving cursor horizontally cannot possibly be slow due to
> bidi, especially as long as point stays in the same screenful. The
> redisplay becomes unbearably slow with long lines only when you either
> scroll the display (e.g., C-v) or for vertical cursor motion, because
> these require the display engine to traverse many buffer positions,
> many more than is needed to just move the cursor, and it currently can
> only start that traversal from the beginning of a physical line.
1) I realize that vertical motion is slower than horizontal, but [2] from
http://debbugs.gnu.org/cgi/bugreport.cgi?bug=15555#65 shows that the major
slowdown happens when cursor is moved horizontally (by right-char) within
the same line.
2) (setq bidi-display-reordering nil) helps bug15555 to run over 4000.txt
just as expected.
Dmitry
This bug report was last modified 2 years and 305 days ago.
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