[Tetuhi-vgs] update, X errors, exhibition

[Douglas Bagnall]

hello

I have been intermittently tinkering with tetuhi.  Some months ago I
removed the GSL dependency and ought to have improved the pseudo-random
qualities of the perceptrons by including dSFMT[1], which led me to
improve some of the ways those numbers were used.

More recently I found that tetuhi was crashing with XIO error messages
when it forked to work in the background.  Previous episodes of this
kind have been caused the child processes making noise on (or attempting
to close) the X sockets, so I assumed some update in pygame or X or SDL
or something had introduced new sensitivity, and tried a haphazard
variety of X swaddling techniques.  With the sockets closed with a dup2
to a "[arw]+" file, the error message to changed to "XIO:  fatal IO
error 0 (Success)" but the children still died.  Then with print
statements I found it was always crashing in a routine related to the
new perceptron randomness code mentioned above, so perhaps X is innocent
except of aiding and abetting bugs by disguising their origin.  If
anyone cares to look the code in question is in the "broken" git
branch[2] (which is not to suggest the master branch is working: it just
contains less debugging code).

So that sounds like a problem just about to be solved (i.e. it is my
stupid perceptron's fault), and you are wondering why I am relating it
at this point and not waiting for the triumph.  The reason is that Te
Tuhi Video Game Machine, the hardware/artwork that initially ran the
code is being shown again, this time at the NZ Film Archive in
Wellington, New Zealand[3].  The exhibition opens at 5:30 on Wednesday,
and if any of you are in this city, please come along and enjoy the free
drinks and food.  The software on the machine is exactly that that was
exhibited in Auckland in November 2007, partly because the current code
is in the aforementioned mess, but mostly because it takes less time and
causes less anxiety to not update things.

douglas

[1]http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/SFMT/
[2]http://git.savannah.gnu.org/gitweb/?p=tetuhi.git;a=shortlog;h=refs/heads/broken
[3]http://www.filmarchive.org.nz/index.php?option=com_events&task=view_detail&agid=1103