xtris -- a multi-player version of Tetris for the X Window system
Roger Espel Llima <roger.espel.llima@pobox.com>
xtris is a version of the classical game of Tetris, for any number of players, for the X Window system.
xtris is a true client/server game (as opposed to a centralized game managing multiple displays), which makes it particularily responsive and bandwith-effective.
Although it has a somewhat motif-ish look and feel, xtris doesn't use any toolkit libraries, which makes it small and easy to compile (and kind of a mess to program).
As an extra bonus, xtris includes a small chat system where players can type messages at each other during the game.
And, the final reason for choosing xtris: it uses exactly the same brick definitions as the original tetris (the one written in Turbo Pascal 3 by the two Russian guys), so when you rotate your brick and drop it, it will fall just where you expect it.
Multi-player games are managed by the xtris server, xtserv; they are synchronous: all users play at the same level, start at the same time, and see each other's games. The game stops when only one player remains.
xtris keeps track of the number of lines each player has filled in the current game, and of the number of games each player has won.
Each player has a name, initially set to his login name, or the contents of the environment variables XTRISNAME or NETTRISNAME.
There are two modes for the game:
- normal
The game starts with an empty pit. Whenever one user fills two or more rows at the same time, these lines appear at the bottom of some other user's screen.
At the beginning of the game, each player is set to send his lines to the next player, in the order of connection to the server. After sending some lines, the server chooses a next victim for the player, sequentially.
- fun
The game starts with some garbage at the bottom and the side of the pit. Whenever one player fills a line, his victim gets an extra gray square at the highest point of his game. Filling two lines simultaneously sends one line; filling three sends three, and filling four sends five.
You can add automatic players, or "bots", to the game, and play against them. Each bot is a running copy of the program 'xtbot', connected to the same server.
Whenever there is more than one player, players can type messages to each other, which appear on a special message area; players who have already lost can chat this way while the game continues.
## installation
Edit the Makefile to suit your (and your system's) tastes, and run make.
Don't forget to set 'BINDIR', because that's where xtris looks for xtserv and xtbot.
At that point, "make install" will copy the 3 binaries and the 3 corresponding manpages to their respective directories.
xtris/xtserv/xtbot should compile OK on any modern POSIX-ish Unix; I've tested them on Linux, SunOS 4, Solaris, and (with some tweaking) on the NeXT. I guess that something that compiles on Solaris and NeXT should really compile anywhere :-).
## playing
To start a game, click on the 'start' button, after choosing your initial level and mode.
Unless started with the -nospeedup option, the server will increase the level whenever the number of lines is greater than 10 times the current level.
xtris recognizes these keys (some of them are shortcuts for the various buttons):
s -- start a game
q -- quit the game
p -- pause/continue the game
n -- change the game mode between normal and fun
b -- start a bot (automatic player)
t -- open/close the message area
c -- clear the message area
v -- toggle verbose mode
z -- set the game counters to 0
0 - 9 -- set the level
Tab -- warp the mouse pointer between the game area,
the nick entry area, and the message area
Return -- toggle seeing the next brick
in addition to the game keys:
J -- move left all the way
j -- move one step to the left
k -- counter-clock-wise rotation
l -- move one step to the right
L -- move right all the way
, -- drop the brick one step
space -- drop the brick all the way
Alternatively, you can use the arrow keys to move the piece around one step, and the shifted arrow keys to move it all the way in each direction. The Up arrow key rotates.
The buttons on the 'xtris' screen are:
start -- start a game (resets the game for all players)
quit -- exit, disconnecting from the server
pause -- pause/continue the game
bot -- start a bot (automatic player) on the same server
0 - 9 -- set the level
normal -- toggle normal/fun game mode
text -- show/hide the message area (only when there are
at least two players)
zero -- set the game counters to 0
verbose -- toggle displaying of server messages about the
game in the message area.
clear -- clear the message area.
Clicking on the area where the Next brick is displayed also toggles displaying the Next.
At any time, you can change your name by moving the mouse pointer on it (at the bottom of your screen) and typing. The only recognized editing keys are ^U to clear the line, Backspace, and Return when you're done.
You can enter accented iso-latin-1 characters by holding down the Meta key (or whatever is set to mod1 in your X11 keyboard mapping).
Clicking on a bot's name, at the bottom of the screen, will remove it from the game.
The message area is a zone under the tetris pits where users can chat by typing messages at each other. It is not displayed by default; to activate it, click on the "msgs" button, which appears as soon as there are two or more users.
When you put your mouse pointer in the message area, the text you type goes to the input line at the very bottom of the window. When you press Return, your line gets sent to all other players.
If you hold down the Shift key when pressing Return in the message area, the mouse pointer gets warped back to the main game. This lets you type in a message quickly during the game: press Tab to warp to the message area, and end your message with Shift-Return to warp back.
## xtris
You start xtris with:
xtris [ -display machine:0 ] [ -help ] [ -k keys ] [ -s ] [ -bw ]
[ -n nick ] [ -big ] [ -flashy ] [ -norestart ] [ -nospeedup ]
[ server.name [ port ] ]
and the options mean:
-bw
With this option, the game will be drawn in black &
white even on a color display.
-big
Makes xtris use larger graphics.
-display
Specify the X display where xtris will open a window to
play the game. By default, xtris connects to the
display specified in the environment variable DISPLAY.
-flashy
Selects an alternate, flashier set of colors for the
tetris bricks.
-help
Prints out a summary of the command-line options xtris
recognizes.
-k Redefine the keys used by xtris. The argument must be a
6-letter string with the keys to move to the left
border, to move one position to the left, to rotate, to
move one position to the right, to move to the right
border and to drop the brick, respectively. The
default keys are 'JjklL '.
-n nick
Sets the nickname for the player. The max nickname
length is 14 characters.
-norestart
Passes the '-norestart' option to xtserv if xtris can't
find a server running and starts one of its own. This
has the effect of telling the server not to automati-
cally restart a game after everyone save one player has
lost.
-nospeedup
Passes the '-nospeedup' option to xtserv if xtris can't
find a server running and starts one of its own. This
has the effect of telling the server not to automati-
cally increase the game speed.
-s Starts the game in standalone mode. In this mode,
xtris will not connect to a server, will not be able to
interact with other players, and will not be able to
start bots.
server.name
Specifies the machine on which an xtris server (xtserv)
runs. xtris will connect to that server, and add
itself to the game.
If the server is not specified, xtris will attempt to
connect to a server on localhost (127.0.0.1). If no
server is running on localhost, xtris will start one
(with the '-once' option so it will not stay after the
client exits).
port
Specifies the port to connect to, if the server was
started on a port other than the default (19503).
xtris also recognizes a number of X resources, all in the form
To redefine keys, the values need to be KeySym names such as 'Return' or 'q' or 'Backspace'. For booleans you can use 'true', 'false', 'on', or 'off'.
The resources to set keys are:
leftBorderKey, leftKey, rotateKey, rightKey, rightBorderKey, downKey, dropKey, startKey, quitKey, pauseKey, botKey, modeKey, msgsKey, toggleNextKey, clearKey, verboseKey, warpKey, zeroKey.
xtris also understands these resources:
name Specifies the player's nickname. The default
is the login name.
big Specifies whether xtris should use larger
graphics or not. The default is ``false''.
flashy Specifies whether xtris should use flashier
colors or not. The default is ``false''.
bw Specifies whether xtris should start up in
black & white mode. The default is
``false''.
verbose Specifies whether xtris should start up in
verbose mode. The default is ``false''.
scrollLines Specifies the size (in lines) of the message
area. The default is 10, and the allowed
values are from 3 to 30.
background Specifies the color used for the background.
## xtserv
If you you start xtserv manually, you do it like this:
xtserv [ -help ] [ -once ] [ -daemon ] [ -v ] [ -norestart ]
[ -nospeedup ] [ -p port ]
and the options mean:
-daemon
Makes xtserv detach from its controlling terminal, fork
twice, close all its file descriptors and change the
current directory to '/'. Useful to start xtserv via
rsh or from scripts.
-help
Prints out a summary of the command-line options xtserv
recognizes.
-once
With this option, xtserv will exit after all clients
have disconnected.
-v Sets verbose mode: xtserv will print information on
clients connecting, disconnecting, starting games,
sending each other lines, losing, etc.
-norestart
With this option, xtserv will not start a new game when
all players but one have lost. The players will have
to press the 'start' button themselves to start.
-nospeedup
With this option, xtserv will not automatically
increase the game speed every time some user's number
of lines is greater than 10 x the current level.
-p Specifies a port for xtserv to use. The default is
19503.
xtserv will automatically restart a game when the one-but-last player has lost, unless started with the option -norestart. It will not automatically restart a game if the user is playing alone.
xtserv will also drop all bots when there are only bots left in the game.
The server can handle clients exiting, being killed or losing the connection even in the middle of a game.
Killing an xtserv will cause all connected clients to exit.
## xtbot
If you you start xtbot manually, you do it like this:
xtbot [ -help ] [ -n nick ] [ -quiet ] [ -test ] [ server.name [ port ] ]
and the options mean:
-help
Prints out a summary of the command-line options xtbot
recognizes.
-n Sets the nickname for the bot; the nickname appears at
the bottom of the screen on xtris clients.
-quiet
Sets quiet mode: xtbot will not output any diagnostics
or error messages. xtris always starts xtbot with this
option.
-test
Runs the bot in test mode: xtbot will not connect to a
server or show the game in progress, but will just
simulate 16 games as fast as it can and print stats on
the number of lines it did and the number of bricks it
played.
server.name
Specifies the machine on which an xtris server (xtserv)
runs. xtbot will connect to that server, and add
itself to the game.
If the server is not specified, xtbot will attempt to
connect to a server on localhost (127.0.0.1). If no
server is running on localhost, xtbot will exit with an
error message.
port
Specifies the port to connect to, if the server was
started on a port other than the default (19503).
xtbot is the robot (i.e automatic player) for xtris. xtbot connects to an xtris server, registers itself as a bot, and simulates a game of Tetris whenever a human player hits 'start'.
The current version of xtbot uses a pretty good decision algorithm, which usually does several thousand lines before losing, when playing on its own. When playing against a bot, though, the main limiting factor is the speed, which is why xtbot purposefully waits a little before dropping each brick, so that humans can compete speed-wise.
xtbot is started automatically by xtris, with the option '-quiet', when a player presses the 'bot' button.
Running copies of xtbot can be killed either by clicking on their name from an xtris window, or by killing the process.
You can make your own bots based on your favorite decision algorithms. For this the easiest way is to change the decision function in decide.c while keeping the rest of the bot's skeleton (in xtbot.c). See the comments in decide.c, decide.h and xtbot.h for details about the interface between these. Alternatively, the protocol between the client and the server is described in detail in the file PROTOCOL, so you can make completely independent bots.
The default algorithm for the bot depends on 6 coefficients to evaluate each possible position of the piece. You can set the environment variables XTBOT_FRONTIER, XTBOT_HEIGHT, XTBOT_HOLE, XTBOT_DROP, XTBOT_PIT, XTBOT_EHOLE. See the file decide.c to see what they do.
The values for the coefficients that xtbot uses now were obtained with a genetic algorithm using a population of 50 sets of coefficients, calculating 18 generations in about 500 machine-hours distributed among 20-odd Sparc workstations. This improved the average number of lines from 10,000 to about 50,000. The code used for this isn't nearly clean enough to distribute in a release. If you're interesed, please e-mail the author privately.
## bugs, things to be improved
There is no way to tell xtris to use keys that do not map to ASCII codes, or to redefine the player's keys from the X interface.
The colors are rather ugly.
The bots' algorithm could still be improved to try to make serveral lines at a time.
If you find bugs, please report them to me.
## acknowledgements
Some bits of X11 code are based on xtet42, a 2-player tetris by Hugo Eide Gunnarsen of the Norwegian Institute of Technology.
Specifically, init_X(), SetColor(), DrawSqr() and DrawButton() are more or less modified versions of the same functions in xtet42.
Also thanks to Fabrice Noilhan <Fabrice.Noilhan@ens.fr> and Denis Auroux <Denis.Auroux@ens.fr> for debugging help, and Laurent Bercot <Laurent.Bercot@ens.fr> and Sebastien Blondeel <Sebastien.Blondeel@ens.fr> for ideas for the bot's decision algorithm.
## license
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
For bug reports, comments, questions, email roger.espel.llima@pobox.com