JJRobots Arena Version 3.0beta (March 2002)
------------------------------

This latest version of the game actually brings a little revolution with it: in
order to obtain faithful results of robot performance across a vast multitude
of environments, OSes, Virtual Machines, CPUs, it was necessary to separate the
time as seen by the robots (virtual time) from the time seen by the observer
(real time), in order to provide constant CPU power per second to the robot
threads.

With this version, the simulation time (or virtual time) is calibrated around
the speed of the machine it's running on by a special "benchmark" function; as
a result, the *real* speed of the simulation now varies according to the speed
of the CPU, JVM and OS.  So, you may notice an increase or decrease of the
number of matches per hour of real time that can be played on your machine, but
you can be (almost!) guaranteed that the performance of the robots tested and
developed on your machine will be consistent across all the possible
environments they could be executed on in the real tournament.  CPU contention
due to other running programs will be gracefully accomodated, causing the
simulation to slow down, rather than becoming "jumpy" as with earlier versions.

A new option has been provided in the user interface: "Display", which can be
set to "Smooth" (60 fps of real time), "Fast" (30 fps of *virtual* time) and
"None", where the match is not shown but the clock counter is updated and the
results are displayed; this setting can be easily changed even within a match.
"None" corresponds most closely with the way actual tournament matches are
executed, as well as being a bit faster.

When watching a match, choose between Smooth and Fast, whichever looks best for
you. While running extended tests, you might consider opting for "None" in
order to get a higher number of matches played per hour.  Whatever you choose,
unless you have a very fast machine you will notice a considerable slow down in
Team play.  That is actually one of the biggest benefits of virtual time, as
it's now granting a lot more CPU time to the robots, which can now make use of
more advanced targeting techniques even in this previously CPU-constrained mode
of play.  

As a way to compensate to for the possible slow down / speed up of
visualization, two new simulation speed settings have been provided: 8X and
1/8X; however, keep in mind that changing the simulation speed actually changes
the CPU time allocated to the robots, so in order to obtain the most faithful
picture of your robot's performance, do intensive testings at the official
speed of 1X.

Finally, you should expect to see some changes to win rates, especially in Team
mode where robots are now given more CPU time than they were previously.


Alan Lund (alan.lund@acm.org)
Walter Nistico' (walnist@infinito.it)