Source/GoGame.m
author Jens Alfke <jens@mooseyard.com>
Sun Mar 16 15:06:47 2008 -0700 (2008-03-16)
changeset 7 428a194e3e59
parent 6 af9b2b929b03
child 10 6c78cc6bd7a6
permissions -rw-r--r--
Game class now tracks board state and moves, as strings, and can step through its history.
Fixed another bug in Go (you could drag your captured stones back to the board!)
     1 /*  This code is based on Apple's "GeekGameBoard" sample code, version 1.0.
     2     http://developer.apple.com/samplecode/GeekGameBoard/
     3     Copyright © 2007 Apple Inc. Copyright © 2008 Jens Alfke. All Rights Reserved.
     4 
     5     Redistribution and use in source and binary forms, with or without modification, are permitted
     6     provided that the following conditions are met:
     7 
     8     * Redistributions of source code must retain the above copyright notice, this list of conditions
     9       and the following disclaimer.
    10     * Redistributions in binary form must reproduce the above copyright notice, this list of
    11       conditions and the following disclaimer in the documentation and/or other materials provided
    12       with the distribution.
    13 
    14     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
    15     IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 
    16     FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRI-
    17     BUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
    18     (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 
    19     PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
    20     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF 
    21     THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    22 */
    23 #import "GoGame.h"
    24 #import "Grid.h"
    25 #import "Piece.h"
    26 #import "Dispenser.h"
    27 #import "Stack.h"
    28 #import "QuartzUtils.h"
    29 #import "GGBUtils.h"
    30 
    31 
    32 @implementation GoGame
    33 
    34 
    35 - (id) initWithBoard: (GGBLayer*)board
    36 {
    37     self = [super initWithBoard: board];
    38     if (self != nil) {
    39         [self setNumberOfPlayers: 2];
    40         [(Player*)[_players objectAtIndex: 0] setName: @"Red"];
    41         [(Player*)[_players objectAtIndex: 1] setName: @"White"];
    42         
    43         CGSize size = board.bounds.size;
    44         CGFloat boardSide = MIN(size.width,size.height);
    45         RectGrid *grid = [[RectGrid alloc] initWithRows: 9 columns: 9 
    46                                                   frame: CGRectMake(floor((size.width-boardSide)/2),
    47                                                                     floor((size.height-boardSide)/2),
    48                                                                     boardSide,boardSide)];
    49         _grid = grid;
    50         grid.backgroundColor = GetCGPatternNamed(@"Wood.jpg");
    51         grid.borderColor = kTranslucentLightGrayColor;
    52         grid.borderWidth = 2;
    53         grid.lineColor = kTranslucentGrayColor;
    54         grid.cellClass = [GoSquare class];
    55         [grid addAllCells];
    56         ((GoSquare*)[grid cellAtRow: 2 column: 2]).dotted = YES;
    57         ((GoSquare*)[grid cellAtRow: 6 column: 6]).dotted = YES;
    58         ((GoSquare*)[grid cellAtRow: 2 column: 6]).dotted = YES;
    59         ((GoSquare*)[grid cellAtRow: 6 column: 2]).dotted = YES;
    60         grid.usesDiagonals = grid.allowsMoves = grid.allowsCaptures = NO;
    61         [board addSublayer: grid];
    62         [grid release];
    63         
    64         CGRect gridFrame = grid.frame;
    65         CGFloat pieceSize = (int)grid.spacing.width & ~1;  // make sure it's even
    66         CGFloat captureHeight = gridFrame.size.height-4*pieceSize;
    67         _captured[0] = [[Stack alloc] initWithStartPos: CGPointMake(2*pieceSize,0)
    68                                                spacing: CGSizeMake(0,pieceSize)
    69                                           wrapInterval: floor(captureHeight/pieceSize)
    70                                            wrapSpacing: CGSizeMake(-pieceSize,0)];
    71         _captured[0].frame = CGRectMake(CGRectGetMinX(gridFrame)-3*pieceSize, 
    72                                           CGRectGetMinY(gridFrame)+3*pieceSize,
    73                                           2*pieceSize, captureHeight);
    74         _captured[0].zPosition = kPieceZ+1;
    75         [board addSublayer: _captured[0]];
    76         [_captured[0] release];
    77         
    78         _captured[1] = [[Stack alloc] initWithStartPos: CGPointMake(0,captureHeight)
    79                                                spacing: CGSizeMake(0,-pieceSize)
    80                                           wrapInterval: floor(captureHeight/pieceSize)
    81                                            wrapSpacing: CGSizeMake(pieceSize,0)];
    82         _captured[1].frame = CGRectMake(CGRectGetMaxX(gridFrame)+pieceSize, 
    83                                           CGRectGetMinY(gridFrame)+pieceSize,
    84                                           2*pieceSize, captureHeight);
    85         _captured[1].zPosition = kPieceZ+1;
    86         [board addSublayer: _captured[1]];
    87         [_captured[1] release];
    88 
    89         [self nextPlayer];
    90         PreloadSound(@"Pop");
    91 }
    92     return self;
    93 }
    94 
    95 
    96 - (Bit*) bitToPlaceInHolder: (id<BitHolder>)holder
    97 {
    98     if( holder.bit != nil || ! [holder isKindOfClass: [GoSquare class]] )
    99         return nil;
   100     NSString *imageName = self.currentPlayer.index ?@"White Ball.png" :@"Red Ball.png";
   101     CGFloat pieceSize = (int)(_grid.spacing.width * 0.9) & ~1;  // make sure it's even
   102     Piece *stone = [[Piece alloc] initWithImageNamed: imageName scale: pieceSize];
   103     stone.owner = self.currentPlayer;
   104     return [stone autorelease];
   105 }
   106 
   107 
   108 - (BOOL) canBit: (Bit*)bit moveFrom: (id<BitHolder>)srcHolder
   109 {
   110     return (srcHolder==nil);
   111 }
   112 
   113 
   114 - (BOOL) canBit: (Bit*)bit moveFrom: (id<BitHolder>)srcHolder to: (id<BitHolder>)dstHolder
   115 {
   116     if( srcHolder!=nil || ! [dstHolder isKindOfClass: [Square class]] )
   117         return NO;
   118     Square *dst=(Square*)dstHolder;
   119     
   120     // There should be a check here for a "ko" (repeated position) ... exercise for the reader!
   121     
   122     // Check for suicidal move. First an easy check for an empty adjacent space:
   123     NSArray *neighbors = dst.neighbors;
   124     for( GridCell *c in neighbors )
   125         if( c.empty )
   126             return YES;                     // there's an empty space
   127     // If the piece is surrounded, check the neighboring groups' liberties:
   128     for( GridCell *c in neighbors ) {
   129         int nLiberties;
   130         [c getGroup: &nLiberties];
   131         if( c.bit.unfriendly ) {
   132             if( nLiberties <= 1 )
   133                 return YES;             // the move captures, so it's not suicidal
   134         } else {
   135             if( nLiberties > 1 )
   136                 return YES;             // the stone joins a group with other liberties
   137         }
   138     }
   139     return NO;
   140 }
   141 
   142 
   143 - (void) bit: (Bit*)bit movedFrom: (id<BitHolder>)srcHolder to: (id<BitHolder>)dstHolder
   144 {
   145     Square *dst=(Square*)dstHolder;
   146     int curIndex = _currentPlayer.index;
   147     // Check for captured enemy groups:
   148     BOOL captured = NO;
   149     for( GridCell *c in dst.neighbors )
   150         if( c.bit.unfriendly ) {
   151             int nLiberties;
   152             NSSet *group = [c getGroup: &nLiberties];
   153             if( nLiberties == 0 ) {
   154                 captured = YES;
   155                 for( GridCell *capture in group )
   156                     [_captured[curIndex] addBit: capture.bit];  // Moves piece to POW camp!
   157             }
   158         }
   159     if( captured )
   160         PlaySound(@"Pop");
   161         
   162     [self nextPlayer];
   163 }
   164 
   165 
   166 // This sample code makes no attempt to detect the end of the game, or count score,
   167 // both of which are rather complex to decide in Go.
   168 
   169 
   170 @end