I'm writing a Swing implementation of Reversi for APCS. My implementation will only click in legal spots, but it doesn't flip the tiles in between. Why is this and how do I fix it?
Here are the relevant sections of code:
private int[][] directions = new int[][] {{0, 1}, {1, 1}, {1, 0}, {1, -1}, {0, -1}, {-1, -1}, {-1, 0}, {-1, 1}};
public void handleTileClick(int x, int y, MouseEvent e) {
if (player == Tile.EMPTY) return;
boolean d = false;
for (int[] dir : directions) {
int dx = dir[0], dy = dir[1];
int curX = x, curY = y;
boolean c = false;
while (tiles[curX+=dx][curY+=dy].getState() == Tile.opposite(player)) c = true;
if (c && tiles[curX][curY].getState() == player) {
while ((curX -= dx) != x && (curY -= dy) != y) {
tiles[curX][curY].setState(player);
}
tiles[x][y].setState(player);
d = true;
}
}
if (d) swapTurn();
}
For completeness, I've made a gist with all the code here
The loop where you flip tiles was not being entered: This should work better:
if (c && tiles[curX][curY].getState() == player) {
do {
curX -= dx;
curY -= dy;
tiles[curX][curY].setState(player);
} while (curX != x || curY != y);
tiles[x][y].setState(player);
d = true;
}
There is also a problem as you approach the edges of the game (i.e. boundary conditions). The current logic will allow curX and curY to be invalid array indices. The following seems to work; change as you see fit:
public void handleTileClick(int x, int y, MouseEvent e) {
if (player == Tile.EMPTY)
return;
boolean d = false;
for (int[] dir : directions) {
int dx = dir[0], dy = dir[1];
int curX = x, curY = y;
boolean c = false;
while (true) {
curX += dx;
curY += dy;
if (curX > 0 && curX < 8 && curY > 0 && curY < 8 && tiles[curX][curY].getState() == Tile.opposite(player))
c = true;
else {
break;
}
}
if (c && curX > 0 && curX < 8 && curY > 0 && curY < 8 && tiles[curX][curY].getState() == player) {
do {
curX -= dx;
curY -= dy;
tiles[curX][curY].setState(player);
} while (curX != x || curY != y);
tiles[x][y].setState(player);
d = true;
}
}
if (d)
swapTurn();
}