Adds a circular arc of the given Radius to the current path. The arc is centered at (XC, YC), begins at Angle and proceeds counter-clockwise during Length radians.

XC : X position of the center of the arc.
YC : Y position of the center of the arc.
Radius : the radius of the arc.
Angle : the start angle, in radians.
Length : the arc length, in radians.
Pie : if a pie should be drawn instead of a chord. By default a chord is drawn.

If Length is negative, then the arc is drawn clockwise.

If Angle and Length are not specified, then a full circle is drawn.

If Angle is specified, but not Length, then nothing is drawn, and the current position is set to the point on the circle at the specified Angle.

Angles are measured in radians. An angle of 0.0 is in the direction of the positive X axis (in user space). An angle of π/2.0 radians (90 degrees) is in the direction of the positive Y axis (in user space). Angles increase in the direction from the positive X axis toward the positive Y axis. So with the default transformation matrix, angles increase in a clockwise direction.

To convert from degrees to radians, use the Rad function.

The arc is circular in user space. To achieve an elliptical arc, use the Ellipse method.