Diagonal Mirroring
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Home * Chess * Position * Diagonal Mirroring
Diagonal mirroring mirrors all pieces along the main diagonal or main anti-diagonal. It is applicable in pawn-less endgames with castling no longer possible. Along with horizontal and/or vertical flipping, diagonal mirroring is used in pawn-less endgame tablebases to restrict a white king to the 10 squares of the a1-d4-d1 triangle of the board.
Mirroring an 8x8 Board
An 8x8 Board with a rank-file mapping needs to swap rank and file. A pure 8x8 Board may be mirrored along the main diagonal that way in C:
int board[64], f, r, sm, sq, s; for (f = 1; f < 8; ++f) for (r = 0; r < f; ++r) { sq = 8*r + f; sm = 8*f + r; s = board[sq]; board[sq] = board[sm]; board[sm] = s; }
Sample Position
Original | Diagonal Mirror | Anti-Diagonal Mirror | |||
---|---|---|---|---|---|
|
|
| |||
k7/8/NK2B3/8/8/8/8/8 w - - | 8/8/8/5B2/8/8/5K2/5N1k w - - | k1N5/2K5/8/8/2B5/8/8/8 w - - |
See also
External Links
- Mirror from Wikipedia
- Mirroring (psychology) from Wikipedia
- Reflection (mathematics) from Wikipedia
- Reflection (physics) from Wikipedia
- Reflection symmetry from Wikipedia