Re: [stella] 2600 Radial Pong

Subject: Re: [stella] 2600 Radial Pong
From: "Roger Williams" <mer02@xxxxxxxxxxxxx>
Date: Fri, 5 Jul 2002 18:13:03 -0700
> I've gotten decently far on my own.  My next challenge is being able to
> choose the horizontal position of the sprites & ball.  I am using
> horizontal motion to move them relative to whatere they started out, but
> I'm not quite sure how to specify where that starting point is.  If you
> guys can pass along any pointers or examples in this area it would be
> great.

You should search the archive for my post "polar to cartesian
co-ordinate conversion demo."  This will give you the tools you
need to make coding the game trivial.  You will need the
P2C converter to make reflections work right, since the way
they are done in games like Combat is a kludge that won't
work in radial co-ordinates.

For the player arcs, you will need to put the sprite in RAM and
plot the arc in the subset of the screen to which it is mapped.
You can position both players and the ball during vertical
retrace.  With the routine I posted, all this should be very easy.

Good luck coding it, it looks like an elegant and worthy game.

--Roger Williams

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