This patch adds several new features and bugfixes to xpilot 4.1.0.
The diff has been made from the standard 4.1.0 xpilot distribution.



BUGFIXES

The following bugs are fixed:
   1. The connector bug.
	The code calculating the forces between a ball and a ship used
	the ship position from the previous frame but the already
	updated ball position from the frame currently being
	calculated. This caused incorrent behaviour especially at high 
	flying speeds.
   2. 4.1.0 lock_nearest.
	4.1.0 introduced a bug that caused the LockNearest key to lock 
	on your own teammates.
   3. Ball grabbing near own treasure.
	If you were near your treasure box and couldn't connect to the
	unmoved ball there, you sometimes were unable to connect to any
	other balls either.
   4.  Lasers disappearing.
	Laser pulses had about 10% change of disappearing when
	wrapping (crossing the edge of the map and appearing on the
	other side).
   5.  LoadLock bug.
	The code handling the LoadLock key had an error that could
	cause illegal memory references and crash the whole server.




COMMAND MODE

The server now recognizes messages starting with / as commands.
They are not sent to other players. Because some of the commands could
ruin a game if used in a hostile way, there is a password mechanism to
restrict access to these commands. To set the password, start the
server with the -password option, like

xpilots -map teamcup.map -password abc

Then, anyone who knows the password 'abc' can send the message
'/password abc' to get operator status and gain access to the
restricted commands.

In the current version, the following commands are recognized.
Commands marked with (operator) require operator status to use.

  /password <string>
   If string matches the current value of the password option, the
   player sending the message gets operator status.

  /set <option> <value>
   The server option <option> is set to <value>. It works like
   the O command when contacting a server. (operator)

  /pause <player name or ID number>
   The player is paused. (operator)

  /lock <optional number>
   Without arguments, tells whether the server is currently locked.
   With nonzero argument locks the server. With zero argument unlocks
   the server. If the last player who has operator status leaves, the
   server is automatically unlocked. (operator to change lock state)

  /team <team number>
   Swaps the player sending the message to another team. If the teams
   are full players can still swap with each other. If the team
   swapped to is full but has paused players one of those can get
   swapped away to make room.

  /help <optional command name>
   Without arguments, lists the available commands. With command name
   as argument gives more info on that command.

  /kick <player name or ID number>
   Removes the player from the server. (operator)

  /version
   Prints the version of patch used.

  /reset, /reset all
   '/reset' starts a new round. '/reset all' additionally sets the
   score of each player to 0 and sets round counter to back to 1.
   These commands can also be used to continue after game over (see
   round counter).

See the end of this text for an example on how to use the command mode
to start a match with limited number of rounds.




MISCELLANEOUS ADDITIONS

Try setting turnresistance to 0 when playing with mouse. This enables
improved mouse control, which should be better especially for players
who have not played with mouse before (but useful for others too).
Note that in this mode the ship turns a lot faster, so you probably
need to lower your turnspeed.


The server shows the number of frames ballruns take.


When there are several balls nearby which you can connect to, the one
chosen is now consistently the closest one. Originally this depended
on the internal data structures of the server.


The server can be used to play a match with fixed number of rounds. If 
the server option numberOfRounds (or numRounds) is set to a nonzero
value, the server prints a notice like < Round 5 out of 12 completed >
after each round. (here numRounds = 12). After the last round, the
game stops. Set numRounds to 0 for unlimited game.
The commands '/reset' and '/reset all' can be used to continue playing
after the game has stopped. /reset turns the round counter off in this 
case (numrounds is set to 0), /reset all starts a new game with the
same round limit. See the end of this text for an example on how to
use the command mode to start a match.


There is a new option called 'wreckage' that controls whether
destroyed ships leave wreckage (default on).


Xpilots times the frame updates by requesting signals from the
operating system at 1/FPS second intervals, then calculating a new
frame whenever a signal arrives. On Linux, the resolution of the
operating system timer is 10 ms. This means that the only possible
real frame rates above 10 FPS are:
10  11.1  12.5  14.3  16.7  20  25  33.3  50  100, for intervals
of 100,90,80,70,60,50,40,30,20 and 10 ms respectively. The one used is 
rounded down from the requested FPS, so if you start a server with
-FPS 33 the server will if fact run at 25 FPS. I added a new option
called timerResolution. If the server is started with timerResolution
set to a nonzero value, it will request signals from the OS at
1/timerResolution second intervals, and calculate a new frame FPS
times out of every timerResolution signals received. This means that
the time between two successive frames can vary by 1/timerResolution
seconds, but this is probably not noticeable because the frames cannot 
be synchronized with client display updates anyway, and the time
between two display updates is greater than 10 ms on normal
monitors/graphic cards. So, to start a server that REALLY runs at 30
FPS (instead of 25) on Linux use a command line like

xpilots -map somemap -FPS 30 -FPSMultiplier 2 -timerResolution 100

Other unixes might have different timing resolutions. At least Digital 
Unix seems to have better resolution.




THE FPSMultiplier OPTION AND RELATED THINGS

The FPSMultiplier option allows you to run a server at frame rates
higher than the normal ugly-looking 12-14 fps without affecting play
otherwise. Normally, if you double the frame rate, everything moves
twice as fast. This option basically allows you to slow everything
down by a factor of 2 (or more) so that when frame rate is doubled
everything should appear normal, except that movement will look a lot
smoother.

To try out this option, start a server with about twice the normal FPS
and the extra option -FPSMultiplier 2. For example, I used the
following command line to start a Bloods server:

xpilots -map teamcup.map -fps 26 -FPSMultiplier 2


The server automatically multiplies the fireRepeatRate and shotLife
options by FPSMultiplier when starting, so don't wonder if they're not
what you expected when checking the server options. Also, the
multiplication is not done automatically if the options are changed
later, which might lead to unexpected results if you are not aware of
this.

The client maxFPS option is 20 by default. If you connect to a server
running at 28 fps with maxFPS 20, you will miss frames at irregular
intervals, which makes screen updates look jumpy. So, to play on a
server running above 20 fps, either start xpilot with a command line
like

xpilot -maxFPS 40 some.computer.somewhere

or after connecting to the server select menu/config from the client
menu and change the maxFPS option found there. Make it as high as it
goes. Starting xpilot with -maxFPS 40 automatically uses the highest
possible value on servers running under 40 fps. It is probably a good
idea to remind users about setting their maxFPS in the MOTD (at least,
I still needed to remind them myself when playing even though I had a
MOTD too...).

There is also a new option called ignore20MaxFPS (default on) which
makes the server ignore a client maxFPS request if it is the default
20.

When playing on a smooth high-fps server for the first time, most
people seem to complain that their ship accelerates slower than normal
or that stopping a moving ship takes a very long distance. This is
probably caused by the fact that high speeds no longer cause your
screen to jump a lot at a time, and people used to low frame rates
therefore fail to realize how fast they are actually moving. You'll
get used to it eventually. If you really doubt that it actually is
slower, try setting maxFPS to one half the frame rate used by the
server. Then you can see how fast it looks with the normal frame rate
you've used to. You can also do this to play on a high-fps server if
your machine isn't fast enough to update the screen many enough times
a second or if you have bandwidth problems.

The FPSMultiplier option hasn't been tested much with maps other that
bloods. Some items not present on bloods might not work properly
when using FPSMultiplier. At least laser firing rate is higher
(doesn't matter that much). 

Amount of turning per frame is still the same for keyboard players.
They need to adjust their turnspeed when FPSMultiplier is used.




EXAMPLE ON USING COMMAND MODE

Players A and B are playing on a bloods map, A on team 4 and B on team 
2. After playing freely for a while, they decide to have a match of 12
rounds. B knows the server password and gets operator status with the
/password command. He types '/set numrounds 12' to set the correct
limit, then '/lock 1' to lock the game (they don't want anyone else
joining the game in the middle of their match). When both players are
ready, B types '/reset all' to set the initial scores to 0 and reset
the round counter. Now they can start playing. After the game is over, 
they decide to try a new match with different teams. A types '/team 2' 
and B '/team 4'. Then B types '/reset all' to start another match with 
the new teams. After this match and checking the results, B uses
'/reset' to start the game again so that others can continue playing.
He can use '/lock 0' to let others join the server again, or just quit 
if he doesn't want to continue playing; the game will be automatically 
unlocked when the only player with operator status leaves.