/**
* Helper method for walk()
*
* @param dir
* @return true if there is no wall in this direction
*/
private boolean checkMove(int dir) {
// obtain appropriate index for direction (CW_BOT, CW_TOP ...)
// for given direction parameter
int a = angle / 90;
if (dir == -1) a = (a + 2) & 3;
// check if cell has walls in this direction
// returns true if there are no walls in this direction
return mazecells.hasMaskedBitsFalse(px, py, Constants.MASKS[a]);
}
