Adds an arc of a circle to the current path, possibly preceded by a straight line segment

SDKs

- iOS 2.0+
- macOS 10.0+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 2.0+

Framework

- Core Graphics

## Declaration

## Parameters

`c`

A graphics context.

`x`

The x-value, in user space coordinates, for the center of the arc.

`y`

The y-value, in user space coordinates, for the center of the arc.

`radius`

The radius of the arc, in user space coordinates.

`startAngle`

The angle to the starting point of the arc, measured in radians from the positive x-axis.

`endAngle`

The angle to the end point of the arc, measured in radians from the positive x-axis.

`clockwise`

Specify

`1`

to create a clockwise arc or`0`

to create a counterclockwise arc.

## Discussion

This method calculates starting and ending points using the radius and angles you specify, uses a sequence of cubic Bézier curves to approximate a segment of a circle between those points, and then appends those curves to the current path.

The clockwise parameter determines the direction in which the arc is created; the actual direction of the final path is dependent on the current transformation matrix of the graphics context. In a flipped coordinate system (the default for UIView drawing methods in iOS), specifying a clockwise arc results in a counterclockwise arc after the transformation is applied.

If the current path already contains a subpath, this method adds a line connecting the current point to the starting point of the arc. If the current path is empty, his method creates a new subpath whose starting point is the starting point of the arc. The ending point of the arc becomes the new current point of the path.