geometry.h

/*
 *  Board geometry
 */

enum file { fileA, fileB, fileC, fileD, fileE, fileF, fileG, fileH };
enum rank { rank1, rank2, rank3, rank4, rank5, rank6, rank7, rank8 };

#define file(square)       ((square) >> 3)
#define rank(square)       ((square) & 7)
#define square(file, rank) (((file) << 3) + (rank))

enum square {
        a1, a2, a3, a4, a5, a6, a7, a8,
        b1, b2, b3, b4, b5, b6, b7, b8,
        c1, c2, c3, c4, c5, c6, c7, c8,
        d1, d2, d3, d4, d5, d6, d7, d8,
        e1, e2, e3, e4, e5, e6, e7, e8,
        f1, f2, f3, f4, f5, f6, f7, f8,
        g1, g2, g3, g4, g5, g6, g7, g8,
        h1, h2, h3, h4, h5, h6, h7, h8,
        boardSize
};