terminal-chess: src/chess/knight.c@824c9522ce66 (annotated)

src/chess/knight.c@824c9522ce66 (annotated)

src/chess/knight.c

Mon, 31 Mar 2014 15:03:25 +0200

author: Mike Becker <universe@uap-core.de>
date: Mon, 31 Mar 2014 15:03:25 +0200
changeset 23: 824c9522ce66
parent 19: 6a26114297a1
child 47: d726e4b46c33
permissions: -rw-r--r--

introduced game state structure

 /*
  * 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.
  *
  */
 #include "knight.h"
 #include "rules.h"
 #include <stdlib.h>
 _Bool knight_chkrules(Move *move) {
     int dx = abs(move->fromfile - move->tofile);
     int dy = abs(move->fromrow - move->torow);
     return (dx == 2 && dy == 1) || (dx == 1 && dy == 2);
 }
 static int knight_getloc_fixedrow(GameState *gamestate, Move *move) {
     int d = 3 - abs(move->fromrow - move->torow);
     if (d == 1 || d == 2) {
         if (move->tofile < 6 &&
             gamestate->board[move->fromrow][move->tofile + d] == move->piece) {
             if (move->fromfile == POS_UNSPECIFIED) {
                 move->fromfile = move->tofile + d;
                 return VALID_MOVE_SYNTAX;
             } else {
                 return AMBIGUOUS_MOVE;
             }
         }
         if (move->tofile > 1 &&
             gamestate->board[move->fromrow][move->tofile - d] == move->piece) {
             if (move->fromfile == POS_UNSPECIFIED) {
                 move->fromfile = move->tofile - d;
                 return VALID_MOVE_SYNTAX;
             } else {
                 return AMBIGUOUS_MOVE;
             }
         }
     }
     return INVALID_POSITION;
 }
 static int knight_getloc_fixedfile(GameState *gamestate, Move *move) {
     int d = 3 - abs(move->fromfile - move->tofile);
     if (d == 1 || d == 2) {
         if (move->torow < 6 &&
             gamestate->board[move->torow + d][move->fromfile] == move->piece) {
             if (move->fromrow == POS_UNSPECIFIED) {
                 move->fromrow = move->torow + d;
                 return VALID_MOVE_SYNTAX;
             } else {
                 return AMBIGUOUS_MOVE;
             }
         }
         if (move->torow > 1 &&
             gamestate->board[move->torow - d][move->fromfile] == move->piece) {
             if (move->fromrow == POS_UNSPECIFIED) {
                 move->fromrow = move->torow - d;
                 return VALID_MOVE_SYNTAX;
             } else {
                 return AMBIGUOUS_MOVE;
             }
         }
     }
     return INVALID_POSITION;
 }
 int knight_getlocation(GameState *gamestate, Move *move) {
     if (move->fromfile != POS_UNSPECIFIED) {
         return knight_getloc_fixedfile(gamestate, move);
     }
     if (move->fromrow != POS_UNSPECIFIED) {
         return knight_getloc_fixedrow(gamestate, move);
     }
     for (int x = -2 ; x <= 2 ; x++) {
         if (x == 0) {
             continue;
         }
         for (int y = -2 ; y <= 2 ; y++) {
             if (y == 0 || y == x) {
                 continue;
             }
             uint8_t cx = move->tofile + x;
             uint8_t cy = move->torow + y;
             if (isidx(cx) && isidx(cy)
                 && gamestate->board[cy][cx] == move->piece) {
                 if (move->fromfile == POS_UNSPECIFIED
                     && move->fromrow == POS_UNSPECIFIED) {
                     move->fromfile = cx;
                     move->fromrow = cy;
                 } else {
                     return AMBIGUOUS_MOVE;
                 }
             }
         }
     }
     if (move->fromfile == POS_UNSPECIFIED || move->fromrow == POS_UNSPECIFIED) {
         return INVALID_POSITION;
     } else {
         return VALID_MOVE_SYNTAX;
     }
 }

Mercurial > hg > terminal-chess / annotate

src/chess/knight.c@824c9522ce66 (annotated)

src/chess/knight.c