mailing-list for TeXmacs Users

[Dennis Nezic <address@hidden>]

On Sun, 3 Nov 2019 04:11:21 +0100, TeXmacs wrote:
> Hi Dennis,
> 
> On Thu, Oct 31, 2019 at 12:16:29PM -0400, Dennis Nezic wrote:
> > I was finally able to compile 1.99.11 without Qt, and it was
> > significantly faster, I think basically the same as the 1.0.7
> > lagginess that I was used to. For example, with the Qt5
> > compilation, simply pressing Home and End on a line of basic text
> > took about a second at 100% cpu, whereas with the X11 port it took
> > about half a second and about 50% cpu. I wish both could be a lot
> > faster, I'm not sure why this would be cpu intensive, but with Qt5
> > it was unbearable.
> 
> I would be interested trying to reproduce the slowness that you
> are experiencing.  Can you please send me a simple test document that
> demonstrates the problem and tell me where to put the cursor and
> press Home and End?  What kind of computer are you working on?
> 
> The algorithm for Home and End may be somewhat suboptimal,
> but 0.5 or 1 second is too long for ordinary text.

Using a couple of QDateTime::currentMSecsSinceEpoch() printf's in
src/Edit/Interface/edit_keyboard.cpp in handle_keypress, I recorded the
following times (in milliseconds) between the top and bottom of the
function:

1094
1086
1097
1115
1089
1091
1094
1090
1089
1091
1083
1093
1083
1241
1084

Just by alternatively pressing Home and End on a line of text such as:
"abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz"

Using a shorter string of text like "abcdef" produced the following
much shorter delays:

35
27
29
33
28
38

(I'm working on a 64bit amd-cpu 1.6Ghz laptop)