Re: [stella] Polar to Cartesian Co-Ordinate Converter

Subject: Re: [stella] Polar to Cartesian Co-Ordinate Converter
From: "Thomas Jentzsch" <tjentzsch@xxxxxx>
Date: Mon, 22 Oct 2001 17:17:46 +0200
Roger Wiliam wrote:
> this is the proof of concept demo for my polar to cartesian
> co-ordinate converter, which?does the operation in 93 to
> 114 machine cycles.

Very cool! And it should be very possible to handle 3D-coordinates that way too.

> The secret to this algorithm is logarithms (now there's
> a word I bet you never thought you'd read in this list).
> The source is fully documented with theory and I have
> placed it in the public domain.?
While I knew the square tables based multiplication, the logarithmic formulas are new to me (or maybe I've forgotten them since school). Thanks!

Especially the fast division may open some new opportunites. To bad, that I can't use them for my new demo, since I need the remainder too :-( 
You don't know a formula for this, do you?

I guess, the rounding error could be further reduced by using 16 bit value tables (for LOG only of course :-) Correct?

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