src/chess/king.c

Wed, 28 May 2014 15:47:57 +0200

author
Mike Becker <universe@uap-core.de>
date
Wed, 28 May 2014 15:47:57 +0200
changeset 47
d726e4b46c33
parent 25
3ab0c2e1a4e2
child 55
54ea19938d57
permissions
-rw-r--r--

refactoring of getlocation mechanism for better short algebraic notation support (does now respect pinned pieces) + fixed a bug where a pawn could advance through a piece (e.g. e2e4 could jump over a piece on e3)

universe@10 1 /*
universe@10 2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
universe@10 3 *
universe@10 4 * Copyright 2014 Mike Becker. All rights reserved.
universe@10 5 *
universe@10 6 * Redistribution and use in source and binary forms, with or without
universe@10 7 * modification, are permitted provided that the following conditions are met:
universe@10 8 *
universe@10 9 * 1. Redistributions of source code must retain the above copyright
universe@10 10 * notice, this list of conditions and the following disclaimer.
universe@10 11 *
universe@10 12 * 2. Redistributions in binary form must reproduce the above copyright
universe@10 13 * notice, this list of conditions and the following disclaimer in the
universe@10 14 * documentation and/or other materials provided with the distribution.
universe@10 15 *
universe@10 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
universe@10 17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
universe@10 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
universe@10 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
universe@10 20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
universe@10 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
universe@10 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
universe@10 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
universe@10 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
universe@10 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
universe@10 26 * POSSIBILITY OF SUCH DAMAGE.
universe@10 27 *
universe@10 28 */
universe@10 29
universe@16 30 #include "rules.h"
universe@10 31 #include "king.h"
universe@25 32 #include <stdlib.h>
universe@10 33
universe@25 34 static _Bool king_castling_chkmoved(GameState *gamestate,
universe@25 35 uint8_t row, uint8_t file) {
universe@25 36
universe@25 37 MoveList *ml = gamestate->movelist;
universe@25 38 while (ml) {
universe@25 39 if (ml->move.fromfile == file && ml->move.fromrow == row) {
universe@25 40 return 1;
universe@25 41 }
universe@25 42 ml = ml->next;
universe@25 43 }
universe@25 44
universe@19 45 return 0;
universe@10 46 }
universe@10 47
universe@25 48 _Bool king_chkrules(GameState *gamestate, Move* move) {
universe@25 49 if (abs(move->torow - move->fromrow) <= 1 &&
universe@25 50 abs(move->tofile - move->fromfile) <= 1) {
universe@25 51 return 1;
universe@25 52 } else {
universe@25 53 /* castling */
universe@25 54 if (move->fromrow == move->torow &&
universe@25 55 move->fromrow == ((move->piece&COLOR_MASK) == WHITE ? 0 : 7) &&
universe@25 56 move->fromfile == fileidx('e') &&
universe@25 57 (move->tofile == fileidx('c') || move->tofile == fileidx('g'))) {
universe@25 58
universe@25 59 return !king_castling_chkmoved(gamestate,
universe@25 60 move->fromrow, move->fromfile) &&
universe@25 61 !king_castling_chkmoved(gamestate, move->fromrow,
universe@25 62 move->tofile == fileidx('c') ? 0 : 7);
universe@25 63 } else {
universe@25 64 return 0;
universe@25 65 }
universe@25 66 }
universe@25 67 }
universe@25 68
universe@23 69 _Bool king_isblocked(GameState *gamestate, Move *move) {
universe@25 70
universe@25 71 uint8_t opponent_color = opponent_color(move->piece&COLOR_MASK);
universe@25 72
universe@47 73 // being in check does not "block" the king, so don't test it here
universe@47 74 _Bool blocked = 0;
universe@47 75
universe@47 76 // just test, if castling move is blocked
universe@25 77 if (abs(move->tofile - move->fromfile) == 2) {
universe@25 78 if (move->tofile == fileidx('c')) {
universe@25 79 blocked |= gamestate->board[move->torow][fileidx('b')];
universe@25 80 }
universe@25 81 uint8_t midfile = (move->tofile+move->fromfile)/2;
universe@25 82 blocked |= gamestate->lastmove->move.check ||
universe@25 83 gamestate->board[move->torow][midfile] ||
universe@25 84 is_covered(gamestate, move->torow, midfile, opponent_color);
universe@25 85 }
universe@25 86
universe@25 87 return blocked;
universe@10 88 }

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