X-Git-Url: https://git.cworth.org/git?p=ttt;a=blobdiff_plain;f=src%2Fttt-board.c;h=bafa0fd56fae79a0873daee57cf06152b4f93f2a;hp=dd068b5850285110f84e5436f2fa99c960b2910d;hb=81fa711bc04271a8c0a0926e6c198f91e797f59a;hpb=b95a33abda8faac3638691dde70de0d59fadb30f

diff --git a/src/ttt-board.c b/src/ttt-board.c
index dd068b5..bafa0fd 100644
--- a/src/ttt-board.c
+++ b/src/ttt-board.c
@@ -19,7 +19,9 @@
  * Author: Carl Worth <cworth@cworth.org>
  */
 
+#include <stdio.h>
 #include "ttt-board.h"
+#include "ttt-error.h"
 
 /* Initialize an empty board. */
 void
@@ -30,6 +32,7 @@ ttt_board_init (ttt_board_t *board)
     {
 	board->cells[i] = TTT_CELL_EMPTY;
     }
+    board->current_player = TTT_CELL_X;
 }
 
 /* Initialize a board from its string representation.
@@ -41,9 +44,21 @@ void
 ttt_board_init_from_string (ttt_board_t *board,
 			    const char  *s)
 {
-    /* XXX: NYI */
+    int i, j;
+    j = 0;
+    for (i = 0; i < strlen (s); i++)
+    {
+	if ((s[i] == 'X') |
+	    (s[i] == 'O') |
+	    (s[i] == '_'))
+	{
+	    board->cells[j] = s[i];
+	    j++;
+	}
+    }
 }
 
+
 /* Return the string representation of a board.
  *
  * The return value is a malloc()ed string that should be free()ed
@@ -82,3 +97,83 @@ ttt_board_write (ttt_board_t *board, FILE *file)
     free (s);
 }
 
+/* Makes a new move in the given board.
+ *
+ * The move value is a number from 0 to 9 giving the position to be
+ * moved as follows:
+ * 
+ *  0|1|2
+ *  3|4|5
+ *  6|7|8
+ *
+ * Returns: TTT_ERROR_NONE if a move is made
+ * succesfully. TTT_ERROR_NOT_VALID_MOVE if a move is invalid (the
+ * given cell is not empty). TTT_ERROR_NOT_GRID if the move is
+ * impossible (user input 'a' or '9' etc.)
+ */
+
+ttt_error_t ttt_board_make_move (ttt_board_t *board, int move)
+{  
+    if (move < 0 || move > 8)
+	return TTT_ERROR_NOT_GRID;
+    
+    if (board->cells[move] != TTT_CELL_EMPTY)
+	return TTT_ERROR_NOT_VALID_MOVE;
+    
+    board->cells[move] = board->current_player;
+    
+    if (board->current_player == TTT_CELL_X)
+	board->current_player = TTT_CELL_O;	
+    else
+	board->current_player = TTT_CELL_X;
+    return TTT_ERROR_NONE;
+}
+
+/* Checks to see if a player has won the game and should be called
+ * after every move.
+ * 
+ * Returns: TTT_CELL_X if X's win. TTT_CELL_O if O's
+ * win. TTT_CELL_EMPTY if no win.  The game can then check the value
+ * of the return and declare the winner.
+ */
+
+ttt_cell_t ttt_board_is_won (ttt_board_t *board)
+{
+    int i;
+
+    /* Loop over rows and columns looking for a win. */
+    for (i = 0; i < 3; i++)
+    {
+	/* Check the current column */
+	if (board->cells[i] != TTT_CELL_EMPTY &&
+	    board->cells[i] == board->cells[i + 3] &&
+	    board->cells[i] == board->cells[i + 6])
+	{
+	    return board->cells[i];
+	}
+	
+	/* Check the current row */
+	if (board->cells[i * 3] != TTT_CELL_EMPTY &&
+	    board->cells[i * 3] == board->cells[(i * 3) + 1] &&
+	    board->cells[i * 3] == board->cells[(i * 3) + 2])
+	{
+	    return board->cells[i * 3];
+	}
+    }
+
+    if (board->cells[0] != TTT_CELL_EMPTY &&
+	board->cells[0] == board->cells[4] &&
+	board->cells[0] == board->cells[8])
+    {
+    	return board->cells[0];
+    }
+
+    if (board->cells[2] != TTT_CELL_EMPTY &&
+	board->cells[2] == board->cells[4] &&
+	board->cells[2] == board->cells[6])
+    {
+    	return board->cells[2];
+    }
+
+    return TTT_CELL_EMPTY;
+}