move(x, y) {
		this.moveTo(this.pos.x + x, this.pos.y + y);
	}
move the camera upper-left position by the specified offset.
@see {@link focusOn}
@param {number} x - horizontal offset
@param {number} y - vertical offset
@example
// Move the camera up by four pixels
me.game.viewport.move(0, -4);