rect(x, y, width, height) {
		this.moveTo(x, y);
		this.lineTo(x + width, y);

		this.moveTo(x + width, y);
		this.lineTo(x + width, y + height);

		this.moveTo(x + width, y + height);
		this.lineTo(x, y + height);

		this.moveTo(x, y + height);
		this.lineTo(x, y);

		this.isDirty = true;
	}
creates a path for a rectangle at position (x, y) with a size that is determined by width and height.
@param {number} x - the x-axis coordinate of the rectangle's starting point.
@param {number} y - the y-axis coordinate of the rectangle's starting point.
@param {number} width - the rectangle's width. Positive values are to the right, and negative to the left.
@param {number} height - the rectangle's height. Positive values are down, and negative are up.