Author: Dan Honeycutt
Date: 01:37:15 08/27/05
Go up one level in this thread
On August 27, 2005 at 03:27:16, Tony Werten wrote: >On August 26, 2005 at 17:01:16, Robert Hyatt wrote: > >>On August 26, 2005 at 16:55:28, Dan Honeycutt wrote: >> >>>On August 26, 2005 at 16:36:47, Dan Honeycutt wrote: >>> >>>>On August 26, 2005 at 16:15:47, Robert Hyatt wrote: >>>> >>>>>On August 26, 2005 at 16:11:53, Dan Honeycutt wrote: >>>>> >>>>>>Run the lowest bits down the a or h file and you can do pawn captures without >>>>>>having to mask those files. >>>>>> >>>>>>Best >>>>>>Dan H. >>>>> >>>>> >>>>>How would you avoid masking? Otherwise the pawn at h2 would still wrap to a3 on >>>>>a shift... >>>> >>>>h8 = bit 0 >>>>h7 = bit 1 >>>>: >>>>a1 = bit 63 >>>> >>>>If I ran that the right way, the out of bounds bits are lost and 0's are shifted >>>>in on the other side. >>>> >>>>Best >>>>Dan H. >>> >>>Looking at it, I think that's right. Take white pawns on g4 and h4 with >>>captures to the right. g4 is bit 12 and h4 is bit 4. My shift is 9 left, so g4 >>>lands on h5 (bit 3) and h4 is discarded. >>> >>>Best >>>Dan H. >> >> >>The problem is that all 64 squares are represented by one bit. So no matter >>what you do, a pawn on the edge is going to wrap around to the other side of the >>board... Because all 64 bits are shifted at once... >> >>Are we talking about the same thing here??? > >The idea is to limit the wrapping around to pawns on the 1st or the 8th rank. >Big change nothing will wrap around :) > >Tony Actually, to prevent pawns on the a file from wrapping to the h file, and vice versa, but, yes. Best Dan H.
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.