terminal-chess: src/rules/pawn.c@7ffd66591afe

     1 /*

     2  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.

     3  *

     4  * Copyright 2014 Mike Becker. All rights reserved.

     5  *

     6  * Redistribution and use in source and binary forms, with or without

     7  * modification, are permitted provided that the following conditions are met:

     8  *

     9  *   1. Redistributions of source code must retain the above copyright

    10  *      notice, this list of conditions and the following disclaimer.

    11  *

    12  *   2. Redistributions in binary form must reproduce the above copyright

    13  *      notice, this list of conditions and the following disclaimer in the

    14  *      documentation and/or other materials provided with the distribution.

    15  *

    16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

    17  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

    18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

    19  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE

    20  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

    21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

    22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

    23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

    24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

    25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

    26  * POSSIBILITY OF SUCH DAMAGE.

    27  *

    28  */

    30 #include "pawn.h"

    32 _Bool pawn_chkrules(Board board, Move *move) {

    33     int8_t d = ((move->piece & COLOR_MASK) == WHITE ? -1 : 1);

    34     if (move->capture) {

    35         if (move->fromrow == move->torow + d && (

    36             move->fromfile == move->tofile + 1 ||

    37             move->fromfile == move->tofile - 1)) {

    39             return mdst(board,move)

    40                 || (board[move->fromrow][move->tofile] & ENPASSANT_THREAT);

    41         } else {

    42             return FALSE;

    43         }

    44     } else {

    45         if (move->fromfile == move->tofile) {

    46             return (move->fromrow == move->torow + d) ||

    47                 (move->fromrow == (d < 0 ? 1 : 6) && /* advanced first move */

    48                 move->fromrow == move->torow + d*2);

    49         } else {

    50             return FALSE;

    51         }

    52     }

    53 }

    55 _Bool pawn_isblocked(Board board, Move *move) {

    56     return mdst(board,move) && !move->capture;

    57 }

    59 _Bool pawn_getlocation(Board board, Move *move) {

    60     int8_t d = ((move->piece & COLOR_MASK) == WHITE ? -1 : 1);

    62     if (move->fromfile == POS_UNSPECIFIED) {

    63         move->fromfile = move->tofile;

    64     }

    65     move->fromrow = move->torow + d;

    66     if (move->fromrow > 6) {

    67         return FALSE;

    68     } else {

    69         /* advanced first move */

    70         if (move->fromrow == (d < 0 ? 2 : 5) &&

    71             msrc(board,move) != move->piece) {

    73             move->fromrow += d;

    74             if (move->fromrow > 6) {

    75                 return FALSE;

    76             }

    77         }

    78     }

    79     return TRUE;

    80 }

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