private boolean collision(int xa, int ya) {
        int xt;
        int yt;

        for (int c = 0; c < 4; c++) {
            xt = ((x + xa) + c % 2 * 12 - 7) >> 4;
            yt = ((y + ya) + c % 2 * 14 + 3) >> 4;
            if (level.getTile(xt, yt).solid()) {
                return true;
            }
        }
        //else
        return false;

    }