Re: [stella] Re: 2600Cookbook - exact horizontal positioning

Subject: Re: [stella] Re: 2600Cookbook - exact horizontal positioning
From: Erik Mooney <erik@xxxxxxxxxx>
Date: Tue, 13 Apr 2004 23:52:13 -0400
On Tue, 13 Apr 2004 19:15:20 -0400, you wrote:

>> This post gives a detailed explanation of exact horizontal positioning:
>A better method is the one rediscovered by Manuel in Battlezone and the
>variations of it:

Well, it's a classic trade-off.  :)  The Battlezone routine is certainly
better than the old Air-Sea Battle conversion routine, but the
lookup-table approach is still faster (at the cost of ROM, of course); it
fits entirely into one scanline plus an HMOVE afterwards.

Kirk, do you have an opinion as to which of the three would be best for
2600 101?  Battlezone is compact, but getting the fine/coarse coordinate
is intertwined with the delay loop and hard to explain.  Air-Sea Battle
goes through an incomprehensible block of code but at least gets a visible
understandable byte with the fine/coarse numbers.  The table lookup also
gets that, but it might be hard to grasp exactly what the table itself

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