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'''[[Main Page|Home]] * [[Board Representation]] * [[Bitboards]] * Flipping, Mirroring and Rotating'''
[[FILE:Forever_IV.jpg|border|right|thumb|link=http://www.barbaramittman.com/Site/Fore_4.html|[[Arts#:Category:Barbara Mittman|Barbara Mittman]], Forever IV <ref>[http://www.barbaramittman.com/Site/Figurative_Paintings.html Figurative Paintings] by [[Arts#:Category:Barbara Mittman|Barbara Mittman]]</ref> ]]
'''Flipping, Mirroring and Rotating'''<br/>
<span id="PseudoRotationby45degrees"></span>
==Pseudo-Rotation by 45 degrees==
The chess-board is four-fold symmetry - thus there is no real 45 degree rotation in the mathematical sense. Anyway we may map [[Diagonals|diagonals]] and [[Anti-Diagonals|anti-diagonals]] to [[ranks]], similar to [[Rotated Bitboards|rotated bitboards]].
===Clockwise===
===Anti-Clockwise===
We enumerate the 15 [[Anti-Diagonals|anti-diagonals]] by 7 ^ (file + rank), a [[Nibble|nibble]] wise [[General Setwise Operations#TheTwosComplement|two's complement]] F == -1.
<pre>
0 F E D C B A 9 1 1 1 1 1 1 1 9
'''[[Bitboards|Up one Level]]'''
[[Category:Barbara Mittman]]
[[Category:Simon Phillips]]
[[Category:Lee Ritenour]]
[[Category:Mike Stern]]
