2005-12-14 Carl Worth <cworth@cworth.org>

[ttt] / src / ttt-board.c

diff --git a/src/ttt-board.c b/src/ttt-board.c
index c6d36f0b42ba161c6070b01a8c7ef5f8e16826c0..f8f62e045de587631fa10c5c1caceee3a3fdecd0 100644 (file)
--- a/src/ttt-board.c
+++ b/src/ttt-board.c
@@ -104,22 +104,57 @@ ttt_error_t ttt_board_make_move (ttt_board_t *board, int move)
        return TTT_ERROR_NOT_VALID_MOVE;
 
     board->cells[move] = board->current_player;
-
+    
     if (board->current_player == TTT_CELL_X)
-    {
-       ttt_board_is_won (board);
        board->current_player = TTT_CELL_O;     
-    }
     else
-    {
-       ttt_board_is_won (board);
        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.
+ * 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 <= 2; 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;
+}