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

Author: Vincent Diepeveen

Date: 05:28:53 12/07/99

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On December 06, 1999 at 15:20:39, Brian Richardson wrote:

>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.

Can you please post at what outdated hardware you tested that?




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