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Subject: Re: Is rotating bb's only useful for movegeneration?

Author: Brian Richardson

Date: 12:20:39 12/06/99

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On December 06, 1999 at 11:29:56, Bas Hamstra wrote:

>Hi Bob and other bb experts,
>
>What do you use the rotated bb's for, exactly: only for movegeneration, or also
>for attack detection?
>
>I ask this because I saw in Crafty some code to detect blocking of sliding
>attacks, like I do it. Whith a BlockMask[File][Rank]. I thought the essence of
>the rotated bb's is that you can avoid this block checking, so why this
>block-code in Crafty?
>
>
>
>Regards,
>Bas Hamstra.

I had done some informal testing of rotated vs non for move generation with
Crafty and found non to be slightly faster (<10%) for move generation (I suspect
due to less overhead updating).  However, for attack detection and eval
functions, I think rotated more than makes up for the additional complexity...

Nonetheless, I do not use rotated in my program for simplicity (at this stage of
development, I prefer KISS to maximum performance).

An easy test would be rotated vs non in Crafty's Attacked() function.
Differences probably vary significantly by game stage and mobility.



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