DAG-Tournament: Real-Time Game Tournament Evaluator

DAG-Tournament
==============

Introduction
------------

DAG-Tournament, where DAG stands for directed acyclic graph, is a graphical
program to manage an informal tournament of games such as foosball. It is
designed for open-for-all tournaments without schedule, for example to
record all games as they happen in the free time program of a serious
event, such as a conference.

Games can be entered as they happen. The program does not generate a
complete ranking, but only visualizes what it knows about who is better
than who based on direct comparison, or a path of direct comparisons.
Cycles are broken at the edge of least significance. The visualisation is
baesd on springs and forces and updated in real time, already producing
entertaining effects.

DAG-Tournaments supports more than one tournament at the same time, e.g.
foosball and pool billard, and can switch between the two rankings with one
keypress, again showing an entaining shuffling of nodes until a stable
state is reached again.

Using
-----

DAG-Tournament has no configuration file and takes no command line optins.
Only if you want to handle more than one game at a time, you need to pass
the names of the games as command line parameters.
$ DAG-Tournament
or
$ DAG-Tournament Foosball Billard

At first, the screen will be blank, because no players or games have been
added. You can now interact with the game in these ways:

Double click
	Add a new player. You will be asked for the name of the player.

Drag’n’drop one player onto another
	Add a new game result. You will be asked for the final score. If
	your game does not have scores, just enter 1:0. 

Tab
	Switch between games, if you have more than one.

Hold shift
	Show the number of games per player. Useful to decide who ought to
	play next.

These are sufficient to use the program. Additionally, there is
functionality meant to be used by the tournament organizer:

Ctrl-R
	Re-set the position of the players. If the nodes are in a
	somehow stuck and you expect that they are not yet in their optimal
	position, this puts them all into a straigt line, possibly allowing
	them to find a better possition on the screen. 

Ctrl-E
	Edit the game state. This opens a text edit window with the list of
	players and games as a raw Haskell value. Here you can edit
	mistakes. If the result does not parse, it will be discarded, so
	edit with care!

	After each change to the game state (adding a new player, adding a
	game result, or using Ctrl-E), it is written to
	~/.DAG-Tournamet.backup. If you need to resume the program, e.g.
	after an accidential close or a crash, you can paste the contents
	of that file to the edit window provided by Ctrl-E


Explanation of the screen contents
----------------------------------

Player names are sometimes coloured. These colours mean:

Red
	Currently hovered by the mouse. All games with this players are
	shown on the left.
Blue
	Start of a drag action. Let go of the mouse above another player to
	enter a game.
Yellow
	A player that has already played at least against once against the
	player marked in red. Useful to find out who he has not yet played
	against.

The back arrows, usually pointing down, indicate that at the current
standings, the upper player is better than the lower, either by direct
comparision or a series of comparisions with intermediate players. Only a
minimal amount of arrows are shown. So if there is an arrow from A to B and
from B to C, there will not be an arrow from A to C, independently of
whether A and C have played each other.

Credits
-------

DAG-Tournamet is © 2009 Joachim Breitner and published under the terms of
the GNU General Public License, Version 2 or later.