ps_circle
说明
bool ps_circle ( resource psdoc, float x, float y, float radius )Draws a circle with its middle point at (x, y). The circle starts and ends at position (x+radius, y). If this function is called outside a path it will start a new path. If it is called within a path it will add the circle as a subpath. If the last drawing operation does not end in point (x+radius, y) then there will be a gap in the path.