CGPathAddArc是否包含圆的中心像素？

Question

I use CGPathAddArc to create a circle, if the radius is 5 pixel, will the whole circle end up with 10 pixels width or 11 pixels?

It's also confusing if it does end up with 10 pixels. In that case, what does it mean that center of a radius?

The CGPathAddArc defined here:

void CGPathAddArc (
CGMutablePathRef path,
const CGAffineTransform *m,
CGFloat x,
CGFloat y,
CGFloat radius,
CGFloat startAngle,
CGFloat endAngle,
bool clockwise
);

Answer 1

It does end up with 10 pixels as the diameter, which includes the center point. As the Apple reference doc says:

When you call this function, you provide the center point, radius, and two angles in radians. Quartz uses this information to determine the end points of the arc

The end points are determined 'including' the center point, so that the entire diameter is 10.