diff -r 6008840b859e -r 6a26114297a1 src/chess/rules.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/chess/rules.h	Mon Mar 31 11:16:32 2014 +0200
@@ -0,0 +1,154 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
+ *
+ * Copyright 2014 Mike Becker. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   1. Redistributions of source code must retain the above copyright
+ *      notice, this list of conditions and the following disclaimer.
+ *
+ *   2. Redistributions in binary form must reproduce the above copyright
+ *      notice, this list of conditions and the following disclaimer in the
+ *      documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef RULES_H
+#define	RULES_H
+
+#include <stdint.h>
+
+#define VALID_MOVE_SYNTAX   0
+#define INVALID_MOVE_SYNTAX 1
+#define INVALID_POSITION    2
+#define AMBIGUOUS_MOVE      3
+#define NEED_PROMOTION      4
+
+
+#define PIECE_MASK       0x0F
+#define COLOR_MASK       0x30
+#define ENPASSANT_THREAT 0x40
+
+#define WHITE 0x10
+#define BLACK 0x20
+
+#define PAWN   0x01
+#define ROOK   0x02
+#define KNIGHT 0x03
+#define BISHOP 0x04
+#define QUEEN  0x05
+#define KING   0x06
+
+#define WPAWN   (WHITE|PAWN)
+#define WROOK   (WHITE|ROOK)
+#define WKNIGHT (WHITE|KNIGHT)
+#define WBISHOP (WHITE|BISHOP)
+#define WQUEEN  (WHITE|QUEEN)
+#define WKING   (WHITE|KING)
+#define BPAWN   (BLACK|PAWN)
+#define BROOK   (BLACK|ROOK)
+#define BKNIGHT (BLACK|KNIGHT)
+#define BBISHOP (BLACK|BISHOP)
+#define BQUEEN  (BLACK|QUEEN)
+#define BKING   (BLACK|KING)
+
+typedef uint8_t Board[8][8];
+
+typedef struct {
+    uint8_t piece;
+    uint8_t fromfile;
+    uint8_t fromrow;
+    uint8_t tofile;
+    uint8_t torow;
+    uint8_t promotion;
+    _Bool check;
+    _Bool checkmate;
+    _Bool capture;
+} Move;
+
+#define POS_UNSPECIFIED UINT8_MAX
+#define mdst(b,m) b[(m)->torow][(m)->tofile]
+#define msrc(b,m) b[(m)->fromrow][(m)->fromfile]
+
+#define isidx(idx) ((uint8_t)idx < 8)
+
+#define isfile(file) (file >= 'a' && file <= 'h')
+#define isrow(row) (row >= '1' && row <= '8')
+
+#define rowidx(row) (row-'1')
+#define fileidx(file) (file-'a')
+
+#define rowchr(row) (row+'1')
+#define filechr(file) (file+'a')
+
+#define chkidx(move) (isidx((move)->fromfile) && isidx((move)->fromrow) && \
+        isidx((move)->tofile) && isidx((move)->torow))
+
+/* secure versions - use, if index is not checked with isidx() */
+#define fileidx_s(c) (isfile(c)?fileidx(c):POS_UNSPECIFIED)
+#define rowidx_s(c) (isrow(c)?rowidx(c):POS_UNSPECIFIED)
+
+/**
+ * Maps a character to a piece.
+ * 
+ * Does not work for pawns, since they don't have a character.
+ * 
+ * @param c one of R,N,B,Q,K
+ * @return numeric value for the specified piece
+ */
+uint8_t getpiece(char c);
+
+/**
+ * Maps a piece to a character.
+ * 
+ * Does not work for pawns, scince they don't have a character.
+ * 
+ * @param piece one of ROOK, KNIGHT, BISHOP, QUEEN, KING
+ * @return character value for the specified piece
+ */
+char getpiecechr(uint8_t piece);
+
+/**
+ * Evaluates a move syntactically and stores the move data in the specified
+ * object.
+ * 
+ * @param board the current state of the board
+ * @param mycolor the color of the current player
+ * @param mstr the input string to parse
+ * @param move a pointer to object where the move data shall be stored
+ * @return status code (see rules/rules.h for the list of codes)
+ */
+int eval_move(Board board, uint8_t mycolor, char *mstr, Move *move);
+
+/**
+ * Validates move by applying chess rules.
+ * @param board the current board state
+ * @param move the move to validate
+ * @return TRUE, if the move complies to chess rules, FALSE otherwise
+ */
+_Bool validate_move(Board board, Move *move);
+
+/**
+ * Applies a move and deletes captured pieces.
+ * 
+ * @param board the current board state
+ * @param move the move to apply
+ */
+void apply_move(Board board, Move *move);
+
+#endif	/* RULES_H */
+