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 92391ebd2d7db4243ed14f76ff7253fa2c9a963f..f8f62e045de587631fa10c5c1caceee3a3fdecd0 100644 (file)
--- a/src/ttt-board.c
+++ b/src/ttt-board.c
@@ -94,31 +94,67 @@ ttt_board_write (ttt_board_t *board, FILE *file)
  *  3|4|5
  *  6|7|8
  *
- * Returns: 1 if a move is made succesfully. O if a move is invalid
- * (the given cell is not empty).
- *
- * Bugs: Currently this function always places X for all moves. So,
- * yeah, we'll need to fix that.
+ * 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_t ttt_board_make_move (ttt_board_t *board, int move)
 {  
-    if (board->cells[move] != '_')
+    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.
+ * 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;
+}