Function

CGPathAddRelativeArc

Appends an arc to a mutable graphics path, possibly preceded by a straight line segment.

Declaration

void CGPathAddRelativeArc(CGMutablePathRef path, const CGAffineTransform *matrix, CGFloat x, CGFloat y, CGFloat radius, CGFloat startAngle, CGFloat delta);

Parameters

path

The mutable graphics path to change.

matrix

A pointer to an affine transformation matrix, or NULL if no transformation is needed. If specified, Core Graphics applies the transformation to the arc before it is added to the path.

x

The x-coordinate of the center point of the arc.

y

The y-coordinate of the center point of the arc.

radius

The radius of the arc.

startAngle

The angle (in radians) that determines the starting point of the arc, measured from the x-axis in the current user space.

delta

The distance the arc should travel (in radians). A positive value indicates a counter-clockwise arc in the current user space.

Discussion

The angle to the second endpoint of the arc is calculated by adding the delta to the start angle.

See Also

Modifying Core Graphics Paths

CGPathAddArc

Appends an arc to a mutable graphics path, possibly preceded by a straight line segment.

CGPathAddArcToPoint

Appends an arc to a mutable graphics path, possibly preceded by a straight line segment.

CGPathAddCurveToPoint

Appends a cubic Bézier curve to a mutable graphics path.

CGPathAddLines

Appends an array of new line segments to a mutable graphics path.

CGPathAddLineToPoint

Appends a line segment to a mutable graphics path.

CGPathAddPath

Appends a path to onto a mutable graphics path.

CGPathAddQuadCurveToPoint

Appends a quadratic Bézier curve to a mutable graphics path.

CGPathAddRect

Appends a rectangle to a mutable graphics path.

CGPathAddRects

Appends an array of rectangles to a mutable graphics path.

CGPathAddRoundedRect

Appends a rounded rectangle to a mutable graphics path.

CGPathApply

For each element in a graphics path, calls a custom applier function.

CGPathMoveToPoint

Starts a new subpath at a specified location in a mutable graphics path.

CGPathCloseSubpath

Closes and completes a subpath in a mutable graphics path.

CGPathAddEllipseInRect

Adds to a path an ellipse that fits inside a rectangle.