roids(1) UNIX System V(10 March 1989) roids(1)
NAME
roids - Dodge and shoot the flying rocks.
SYNOPSIS
roids [-display display:number]
DESCRIPTION
roids is an implementation of the old Atari Asteroids game, on top of the
X11 window system. Be warned that it only works on very fast
workstations.
PLAYING ROIDS
Initially, you will be presented with a black window. Nothing will
happen until you give input focus to that window. (How you do this
depends on your window manager; in most of them, you just move the mouse
into the roids window. In some, you'll have to click the mouse as well.)
Once you get things going, you'll find yourself in control of a small
triangular ship, dodging big rocks. Your controls are:
z Rotate the ship to the left. It will continue rotating as long
as the key stays depressed.
x Rotate the ship to the right. It will continue rotating as long
as the key stays depressed.
, Apply thrust. Thrusting will continue as long as the key remains
depressed.
. Fire a bullet. You may have up to four bullets flying at once.
Q Abort the game. This must be entered as a capital Q (the shift
key must be down).
If you prefer, you may control your ship with the mouse. The
controls here are:
Left Rotate the ship to point towards the mouse arrow.
Middle Apply thrust.
Right Fire a bullet.
SCORING
Big rocks are worth 50 points. Medium rocks are worth 100 points. Small
rocks are worth 200 points.
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You have three ships. You get a free ship every 10,000 points.
CUSTOMIZING COLORS
As with all standard X applications, roids may be customized through
entries in the resource manager. This almost always means editing your
.Xdefaults file. [Note: the entry names must be entered in either all
lower-case, or in the exact case shown below.]
ShipColor
The color to paint your ship. (Default is green.)
RockColor
The color to paint rocks. (Default is gold.)
ShotColor
The color to paint shots. (Default is red.)
ScoreColor
The color to paint the score. (Default is violetred.)
CUSTOMIZING MOUSE AND KEYBOARD
If you wish to set up your own interpretation of the mouse and keyboard,
the following actions are provided:
grab-focus
Grab the input focus. This is only useful if bound to a mouse
action.
rotate-left
Start rotating the ship to the left.
rotate-right
Start rotating the ship to the right.
rotate-off
Stop any rotation.
thrust-on
Begin thrusting.
thrust-off
Stop thrusting.
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rotate-to-point
Begin rotating to point to where the mouse is pointing. This may
only be bound to a mouse-down action.
stop-rotate
Cancel a currently executing rotate-to-point. This may only be
bound to a mouse-up action.
rotate-moved
Change the point to rotate to. This may only be bound to a
mouse-motion action.
fire Fire a shot.
quit Quit the game.
It is beyond the scope of this document to describe how to use these
actions in your .Xdefaults file to change the keyboard and mouse
interpretation. As an example, though, here is what you would use to get
the default behavior:
Roids*Roids*translation: \n\
<Btn1Down>: grab-focus() rotate-to-point()\n\
Button1<PtrMoved>: rotate-moved()\n\
<Btn1Up>: stop-rotate()\n\
<Btn2Down>: thrust-on()\n\
<Btn2Up>: thrust-off()\n\
<Btn3Down>: fire()\n\
<KeyDown>z: rotate-left()\n\
<KeyUp>z: rotate-off()\n\
<KeyDown>x: rotate-right()\n\
<KeyUp>x: rotate-off()\n\
<KeyDown>\\,: thrust-on()\n\
<KeyUp>\\,: thrust-off()\n\
<KeyDown>.: fire()\n\
Shift<KeyDown>q: quit()
MOTIVATION
I've always wanted to write one of these games. Unfortunately, I don't
enjoy optimizing code to be very fast, and that's what has always been
necessary for good arcade games on every machine I've used.
Until I got my DECstation 3100. This machine is fast enough that I
didn't have to write efficient code. Roids does stupid things like
repainting the ships location 100 times a second, and it doesn't matter.
Thus, I have written a game that (probably unnecessarily) requires a very
fast workstation. Please don't interpret this as snobbishness on my part
("your workstation isn't as fast as mine so you can't play my game, nyah
nyah"); it is just laziness.
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NOTES
There are lots more resources. The ones above are the only ones I want
documented; the rest change the behavior of the game. The curious should
look at the source.
The mouse controls are, in my opinion, useless. I'd be very interested
if anyone actually likes them. (I implemented them for a friend who
refuses to use his keyboard to play games.)
Collision detection is very good. I actually check to see if things
touch; I refused to use the standard method of just seeing if the centers
of objects are close. Of course, this is a large part of why roids needs
a fast workstation.
Roids works only on very fast workstations. Don't try and play it over a
network; it won't work.
BUGS
The rocks look really stupid. Anyone have some good rock designs?
You shouldn't have to re-run the program to play another game.
There should be high-score mechanisms.
Doesn't handle different visuals like a good X client should. In
particular, if you play this on a display with a StaticGrey visual, you
will probably not be able to see anything.
The default colors don't show up well on all displays.
No enemy ships. In a way, this is a feature; I always despised the fact
that people could get lots of points in the original Asteroids by leaving
one tiny little rock and blasting all the enemy ships.
The code really could be a lot more efficient, and therefore work well
over a larger variety of machines.
COPYRIGHT
Copyright 1989 Digital Equipment Corporation
Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted, provided
that the above copyright notice appear in all copies and that both that
copyright notice and this permission notice appear in supporting
documentation, and that the name of Digital Equipment Corporation not be
used in advertising or publicity pertaining to distribution of the
software without specific, written prior permission. Digital Equipment
Corporation makes no representations about the suitability of this
software for any purpose. It is provided "as is" without express or
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roids(1) UNIX System V(10 March 1989) roids(1)
implied warranty.
DIGITAL EQUIPMENT CORPORATION DISCLAIMS ALL WARRANTIES WITH REGARD TO
THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS, IN NO EVENT SHALL DIGITAL EQUIPMENT CORPORATION BE LIABLE FOR
ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
AUTHOR
Terry Weissman
Western Software Laboratory
Digital Equipment Corporation
weissman@wsl.dec.com
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