VECTORLIST - The Mailing List For The Technical Discussion of Vector-Based Arcade Games

November_1999
Re: Gravity Calculation


From: Zonn ( )
Date: Tue Nov 02 1999 - 12:07:08 CST


On Mon, 1 Nov 1999 22:30:17 -0700 , you wrote:

>The look up table would have to be 131,072 bytes in size.
>((256*256)+(256*256))

Not using the shift lookup technique I described in an earlier message
for the sqrt() function. Using the upper 8 bits as the index into the
lookup table allows for a lookup table of 1272 bytes (assuming 1 byte
results of the ^-1.5 function, the sqrt() always returned an answer
that fit in one byte, this might not be true for the ^-1.5 function).
Of course this limits your results to one of 1272 possible answers
which is probably more than enough resolution.

-Zonn


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