create(digCallback) {
        let sx = this._startX;
        let sy = this._startY;
        let dx = this._endX - sx;
        let dy = this._endY - sy;
        let length = 1 + Math.max(Math.abs(dx), Math.abs(dy));
        if (dx) {
            dx = dx / Math.abs(dx);
        }
        if (dy) {
            dy = dy / Math.abs(dy);
        }
        for (let i = 0; i < length; i++) {
            let x = sx + i * dx;
            let y = sy + i * dy;
            digCallback(x, y, 0);
        }
        return true;
    }
@param {function} digCallback Dig callback with a signature (x, y, value). Values: 0 = empty.