The center of the ellipse is the center of the bounding rectangle specified by x1, y1, x2, and y2, or lpRect. The ellipse is drawn with the current pen, and its interior is filled with the current brush.
The figure drawn by this function extends up to, but does not include, the right and bottom coordinates. This means that the height of the figure is y2 – y1 and the width of the figure is x2 – x1.
If either the width or the height of the bounding rectangle is 0, no ellipse is drawn.