.\"	$OpenBSD: atc.6,v 1.6 2001/02/04 02:15:28 pjanzen Exp $
.\"
.\" Copyright (c) 1990, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" This code is derived from software contributed to Berkeley by
.\" Ed James.
.\"
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.\" modification, are permitted provided that the following conditions
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.\"    notice, this list of conditions and the following disclaimer.
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.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\"	@(#)atc.6	8.1 (Berkeley) 5/31/93
.\"
.\" Copyright (c) 1986 Ed James. All rights reserved.
.\"
.Dd May 31, 1993
.Dt ATC 6
.Os
.Sh NAME
.Nm atc
.Nd air traffic controller game
.Sh SYNOPSIS
.Nm atc
.Op Fl u?lstpq
.Op Fl gf Ar "game name"
.Op Fl r Ar "random seed"
.Sh DESCRIPTION
.Nm
lets you try your hand at the nerve-wracking duties of an air traffic
controller without endangering the lives of millions of
travelers each year.
Your responsibilities require you to direct the flight of jets
and prop planes into and out of the flight arena and airports.
The speed (update time) and frequency of the planes depend on the
difficulty of the chosen arena.
.Sh OPTIONS
.Bl -tag -width "-g gamex"
.It Fl u
Print the usage line and exit.
.It Fl ?
Same as
.Fl u .
.It Fl l
Print a list of available games and exit.
The first game name printed is the default game.
.It Fl s
Print the score list (formerly the Top Ten list).
The scoring information is the game time in
.Dq radar updates ,
the wall-clock game time, and the number of planes that were
successfully dealt with.
.It Fl t
Same as
.Fl s .
.It Fl p
Print the path to the special directory where
.Nm
expects to find its private files.  This is used during the
installation of the program.
.It Fl q
Play quietly (no bells).
.It Fl g Ar game
Play the named game.  If the game listed is not one of the
ones printed from the
.Fl l
option, the default game is played.
.It Fl f Ar game
Same as
.Fl g .
.It Fl r Ar seed
Set the random seed.  The purpose of this flag is questionable.
.El
.Sh GOALS
Your goal in
.Nm
is to keep the game going as long as possible.
There is no winning state, except to beat the times of other players.
You will need to: launch planes at airports (by instructing them to
increase their altitude); land planes at airports (by instructing them to
go to altitude zero when exactly over the airport); and maneuver planes
out of exit points.
.Pp
Several things will cause the end of the game.
Each plane has a destination (see information area), and
sending a plane to the wrong destination is an error.
Planes can run out of fuel, or can collide.  Collision is defined as
adjacency, horizontal or vertical.  A plane leaving the arena
in any other way than through its correct destination exit is an error
as well.
.Pp
Scores are sorted in order of the number of planes safe.  The other
statistics are provided merely for fun.  There is no penalty for
taking longer than another player (except in the case of ties).
.Pp
Suspending a game is not permitted.  If you get a talk message, tough.
When was the last time an Air Traffic Controller got called away to
the phone?
.Sh "THE DISPLAY"
Depending on the terminal used, the
.Nm
screen will be divided into 4 areas.
It should be stressed that the terminal driver portion of the
game was designed to be reconfigurable, so the display format can vary
depending the version you are playing.  The descriptions here are based
on the ASCII version of the game.  The game rules and input format, however,
should remain consistent.
Control-L redraws the screen, should it become muddled.
.Ss RADAR
The first screen area is the radar display, showing the relative locations
of the planes, airports, standard entry/exit points, radar
beacons, and
.Dq lines
which simply serve to aid you in guiding
the planes.
.Pp
Planes are shown as a single letter with an altitude.  If
the numerical altitude is a single digit, then it represents
thousands of feet.
Some distinction is made between the prop
planes and the jets.  On ASCII terminals, prop planes are
represented by an upper case letter, jets by a lower case letter.
.Pp
Airports are shown as a number and some indication of the direction
planes must be going to land at the airport.
On ASCII terminals, this is one of
.Sq ^ ,
.Sq \&> ,
.Sq \&< ,
or
.Sq v ,
to indicate
north (0 degrees), east (90), west (270) and south (180), respectively.
The planes will also
take off in this direction.
.Pp
Beacons are represented as circles or asterisks and a number.
Their purpose is to offer a place of easy reference to the plane pilots.
See
.Dq The Delay Command
under the input section of this manual.
.Pp
Entry/exit points are displayed as numbers along the border of the
radar screen.  Planes will enter the arena from these points without
warning.  These points have a direction associated with them, and
planes will always enter the arena from this direction.  On the
ASCII version of
.Nm atc ,
this direction is not displayed.  It will become apparent
what this direction is as the game progresses.
.Pp
Incoming planes will always enter at the same altitude: 7000 feet.
For a plane to depart successfully through an entry/exit point,
it must be flying at 9000 feet.
It is not necessary for the planes to be flying in any particular
direction when they leave the arena (yet).
.Ss "INFORMATION AREA"
The second area of the display is the information area, which lists
the time (number of updates since start) and the number of planes you
have directed safely out of the arena.
Below this is a list of planes currently in the air, followed by a
blank line, and then a list of planes on the ground (at airports).
Each line lists the plane name and its current altitude,
an optional asterisk indicating low fuel, the plane's destination,
and the plane's current command.  Changing altitude is not considered
to be a command and is therefore not displayed.  The following are
some possible information lines:
.Pp
.Dl B4*A0: Circle @ b1
.Pp
.Dl g7 E4: 225
.Pp
The first example shows a prop plane named
.Sq B
that is flying at 4000
feet.  It is low on fuel (note the
.Sq * ) .
Its destination is
Airport #0.
The next command it expects
to do is circle when it reaches Beacon #1.
The second example shows a jet named
.Sq g
at 7000 feet, destined for
Exit #4.  It is just now executing a turn to 225 degrees (Southwest).
.Ss "INPUT AREA"
The third area of the display is the input area.  It is here that
your input is reflected.  See the INPUT heading of this manual
for more details.
.Ss "AUTHOR AREA"
This area is used simply to give credit where credit is due. :-)
.Sh INPUT
A command completion interface is built into
the game.  At any time, typing
.Sq ?
will list possible input characters.
Typing a backspace (your erase character) backs up, erasing the last part
of the command.  When a command is complete, a return enters it, and
any semantic checking is done at that time.  If no errors are detected,
the command is sent to the appropriate plane.  If an error is discovered
during the check, the offending statement will be underscored and a
(somewhat) descriptive message will be printed under it.
.Pp
The command syntax is broken into two parts:
.Em Immediate Only
and
.Em Delayable
commands.
.Em Immediate Only
commands happen on the next
update.
.Em Delayable
commands also happen on the next update unless they
are followed by an optional predicate called the
.Em Delay
command.
.Pp
In the following tables, the syntax
.Em [0\-9]
means any single digit, and
.Em <dir>
refers to the keys around the
.Sq s
key, namely
.Dq wedcxzaq .
In absolute references,
.Sq q
refers to Northwest or 315 degrees, and
.Sq w
refers to North, or 0 degrees.
In relative references,
.Sq q
refers to \-45 degrees or 45 degrees left, and
.Sq w
refers to 0 degrees, or no change in direction.
.Pp
All commands start with a plane letter.  This indicates the recipient
of the command.  Case is ignored.
.Ss "IMMEDIATE ONLY COMMANDS"
.Bd -ragged
.Bl -tag -width "aaaa"
.It Sy "a [ cd+- ]" Em number
Altitude:
Affect a plane's altitude, possibly requesting takeoff.
.Sq \&+
and
.Sq \&-
are the same as
.Sq c
and
.Sq d .
.Bl -tag -width "aaaaaaaaaa" -compact
.It Sy a [0\-9]
Go to the given altitude (thousands of feet).
.It Sy c [0\-9]
Climb:
Relative altitude change (thousands of feet).
.It Sy d [0\-9]
Descend
Relative altitude change (thousands of feet).
.El
.It Sy m
Mark:
Display in highlighted mode.  Plane and command information is
displayed normally.
.It Sy i
Ignore:
Do not display highlighted.  Command information is displayed as a
line of dashes if there is no command.
.It Sy u
Unmark:
Same as ignore, but if a delayed command is processed,
the plane will become marked.  This is useful if you want
to forget about a plane during part, but not all, of its
journey.
.El
.Ed
.Ss "DELAYABLE COMMANDS"
.Bd -ragged
.Bl -tag -width "aaaa"
.It Sy c
Circle:
Have the plane circle.
.It Sy "t [ l-r+LR ] [ dir ]" No or Sy "tt [ abe* ]" Em number
Turn:
Change direction.
.Bl -tag -width "aaaaaaaaaa" -compact
.It Sy t<dir>
Turn to the absolute compass heading given.
The shortest turn will be taken.
.It Sy tl
Left:
Turn counterclockwise (45 degrees by default).
.Bl -tag -width "tl <dir>" -compact
.It Sy tl <dir>
Turn ccw the given number of degrees.
Zero degrees
.Pq Sq w
is no turn; 45 degrees ccw is
.Sq e .
The shortest turn will be taken; for instance, if you specify
a ccw turn of 315 degrees
.Pq Sq q ,
which should take several turns,
the plane will really turn 45 cw, which takes only one turn.
.El
.It Sy tr
Right:
Turn clockwise (45 degrees by default).
.Bl -tag -width "tl <dir>" -compact
.It Sy tr <dir>
Analogous to turn left <dir>.
.El
.It Sy tL
Turn counterclockwise 90 degrees.
.It Sy tR
Turn clockwise 90 degrees.
.It Sy "tt [abe*]"
Towards:
Turn towards a beacon, airport or exit.  The turn is
just an estimate.
.Bl -tag -width "aaaaaaaaaa" -compact
.It Sy ttb Em number
Turn towards the specified beacon.
.It Sy tt* Em number
Equivalent to
.Sy ttb .
.It Sy tte Em number
Turn towards the specified exit.
.It Sy tta Em number
Turn towards the specified airport.
.El
.El
.El
.Ed
.Ss "THE DELAY COMMAND"
The
.Em Delay
(a/@)
command may be appended to any
.Em Delayable
command.  It allows the controller to instruct a plane to do an action
when the plane reaches a particular beacon (or other objects in future
versions).
.Pp
.Bd -ragged -offset indent
.Bl -tag -width indent -compact
.It Sy a/@
At:
Do the given delayable command when the plane reaches the given beacon.
.Bl -tag -width "aaaaaaaaaa" -compact
.It Sy ab Em number
The letter is redundant to allow for expansion.
.Sq \&@
can be used instead of
.Sq a .
.El
.El
.Ed
.Ss "MARKING, UNMARKING AND IGNORING"
.Pp
Planes are
.Em marked
by default when they enter the arena.  This means they are displayed
in highlighted mode on the radar display.  A plane may also be either
.Em unmarked
or
.Em ignored.
An
.Em unmarked
plane is drawn in unhighlighted mode, and a line of dashes is displayed in
the command field of the information area.  The plane will remain this
way until a mark command has been issued.  Any other command will be issued,
but the command line will return to a line of dashes when the command
is completed.
.Pp
An
.Em ignored
plane is treated the same as an unmarked plane, except that it will
automatically switch to
.Em marked
status when a delayed command has been processed.  This is useful if
you want to forget about a plane for a while, but its flight path has
not yet been completely set.
.Pp
As with all of the commands, marking, unmarking and ignoring will take effect
at the beginning of the next update.  Do not be surprised if the plane does
not immediately switch to unhighlighted mode.
.Ss EXAMPLES
.Bd -ragged -offset indent
.Bl -tag -width "gtte4ab2"
.It atlab1
Plane A: turn left at beacon #1
.It cc
Plane C: circle
.It gtte4ab2
Plane G: turn towards exit #4 at beacon #2
.It ma+2
Plane M: altitude: climb 2000 feet
.It stq
Plane S: turn to 315
.It xi
Plane X: ignore
.El
.Ed
.Sh "OTHER INFORMATION"
.Bl -bullet
.It
Jets move every update; prop planes move every other update.
.It
All planes turn a most 90 degrees per movement.
.It
Planes enter at 7000 feet and leave at 9000 feet.
.It
Planes flying at an altitude of 0 crash if they are not over an airport.
.It
Planes waiting at airports can only be told to take off (climb in altitude).
.El
.Sh "NEW GAMES"
The
.Pa Game_List
file lists the currently available play fields.  New field description
file names must be placed in this file to be playable.  If a player
specifies a game not in this file, his score will not be logged.
.Pp
The game field description files are broken into two parts.  The first
part is the definition section.  Here, the four tunable game parameters
must be set.  These variables are set with the syntax:
.Pp
.Dl "variable = number;"
.Pp
Variable may be one of:
.Li update,
indicating the number of seconds between forced updates;
.Li newplane,
indicating (about) the number of updates between new plane entries;
.Li width,
indicating the width of the play field; or
.Li height,
indicating the height of the play field.
.Pp
The second part of the field description files describes the locations
of the exits, the beacons, the airports and the lines.
The syntax is as follows:
.Pp
.Bd -ragged -offset indent
.Bl -tag -width "airport:" -compact
.It beacon:
(x y) ... ;
.It airport:
(x y direction) ... ;
.It exit:
(x y direction) ... ;
.It line:
[ (x1 y1) (x2 y2) ] ... ;
.El
.Ed
.Pp
For beacons, a simple x, y coordinate pair is used (enclosed in parenthesis).
Airports and exits require a third value, a direction, which is one
of
.Dq wedcxzaq .
For airports, this is the direction that planes must be going to take
off and land, and for exits, this is the direction that planes will going
when they enter
the arena.  This may not seem intuitive, but as there is no restriction on
direction of exit, this is appropriate.
Lines are slightly different, since they need two coordinate pairs to
specify the line endpoints.  These endpoints must be enclosed in
square brackets.
.Pp
All statements are semi-colon (;) terminated.  Multiple item statements
accumulate.  Each definition must occur exactly once, before any
item statements.  Comments begin with a hash (#) symbol
and terminate with a newline.
The coordinates are between zero and width-1 and height-1
inclusive.  All of the exit coordinates must lie on the borders, and
all of the beacons and airports must lie inside of the borders.
Line endpoints may be anywhere within the field, so long as
the lines are horizontal, vertical or
.Em exactly
diagonal.
.Ss "FIELD FILE EXAMPLE"
.Bd -literal -offset indent
# This is the default game.

update = 5;
newplane = 5;
width = 30;
height = 21;

exit:		( 12  0 x ) ( 29  0 z ) ( 29  7 a ) ( 29 17 a )
		(  9 20 e ) (  0 13 d ) (  0  7 d ) (  0  0 c ) ;

beacon:		( 12  7 ) ( 12 17 ) ;

airport:	( 20 15 w ) ( 20 18 d ) ;

line:		[ (  1  1 ) (  6  6 ) ]
		[ ( 12  1 ) ( 12  6 ) ]
		[ ( 13  7 ) ( 28  7 ) ]
		[ ( 28  1 ) ( 13 16 ) ]
		[ (  1 13 ) ( 11 13 ) ]
		[ ( 12  8 ) ( 12 16 ) ]
		[ ( 11 18 ) ( 10 19 ) ]
		[ ( 13 17 ) ( 28 17 ) ]
		[ (  1  7 ) ( 11  7 ) ] ;
.Ed
.Sh FILES
Files are kept in a special directory. See the OPTIONS for a way to
print this path out.
.Pp
.Bl -tag -width "/usr/share/games/atc/Game_List" -compact
.It Pa /var/games/atc_score
Score file
.It Pa /usr/share/games/atc/Game_List
The list of playable games.
.Sh AUTHOR
Ed James, UC Berkeley: edjames@ucbvax.berkeley.edu, ucbvax!edjames
.Pp
This game is based on someone's description of the overall flavor
of a game written for some unknown PC many years ago, maybe.
.Sh BUGS
The screen sometimes refreshes after you have quit.