Author: Robert Hyatt
Date: 05:53:12 12/06/99
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On December 05, 1999 at 22:47:06, KarinsDad wrote: >On December 05, 1999 at 11:00:19, Robert Hyatt wrote: > >[snip] >> >> >>you need 256 entries because that is the number of possible states of any rank >>or diagonal. > >Hmmmm. I'll have to think about this for a while. Seems wasteful on the surface. > >> >>As far as 64 bits goes, within 5 years that is _all_ we will have. Better to >>plan for the future. It is almost the present. :) > >Heck, I cannot even get the present working. ;) > >KarinsDad :) Think about this: you want a 64 bit value, which has 1 bits set for each square the piece in question attacks. For sliding pieces, look at a rank. The rank can have exactly 256 different states when each square is represented by 1 bit, with 0=empty and 1=occupied. You grab the rank contents and use that as an index into this 256 element array to instantly look up the squares the piece attacks along that rank.
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