XSC is a clone of the old Star Castle video game by Cinematronics.
Most of the details are from memory and a few old video game books I have
kicking around from the golden days.  This is just a fun hack that I've
been working on off and on for quite a long time.  I don't have any grand
plans for it, except to hack on it when I feel like it.  It's always
good to have something like this available when you feel like flying
around and blasting the crap out of some alien bad guy for a few minutes.

The program should build on any reasonable UNIX box with a decent C++
compiler and X libraries installed.  Some portability adjustments may
be necessary depending on what variety of bogosities exist in your C++
development environment.  As of version 1.3, the code is known to compile
with recent versions of g++ and Sun's WorkShop C++ 5.0.  If you need
to modify it to build on another platform, send me the changes and I'll
try to work them into my repository.

To specify optimization flags when building, I suggest:

CXXFLAGS="-O2 -fomit-frame-pointer" ./configure

or something similar for GCC, and:

CXXFLAGS="-xO3" ./configure

for Sun's WorkShop C++ compiler.

Installation is trivial, as there is currently only an executable and
no supporting files.  Just put the xsc binary somewhere in your PATH
and blast away.

Instructions:
=============

- D turns the ship counter-clockwise
- F turns the ship clockwise

- J runs the thruster
- K fires the laser

- P toggles the pause (moving the cursor out of the window pauses the game)
- Q quits the game
- space starts a new game

The object is to blast a hole in the rings and destroy the enemy ship.
The only problem is that it tracks your every move and as soon as you
knock a hole in all three rings, and they all line up, it lets loose
with the big nasty green fireballs.  Avoid them.  Avoid the little green
buzzers, too.  Shoot 'em if you want.

Destroying all the segments of the outer ring causes a new solid ring
to be generated.  You must hit each ring segment twice to destroy it.

If you kill off the enemy ship, you are given another life.
