addArc

addArc is a method in the Android graphics library that appends an arc segment to an existing Path object. The arc is defined by the bounds of an oval and by two angles that determine its start point and sweep length within that oval.

The method signature commonly appears as addArc(RectF oval, float startAngle, float sweepAngle), with an overloaded form that accepts individual left, top, right, bottom coordinates for the oval. The parameters are as follows: oval (a RectF describing the oval’s bounds), startAngle (the starting angle in degrees), and sweepAngle (the arc’s length in degrees). Angles are measured in degrees with 0 degrees at the 3 o’clock position, and positive values sweeping clockwise. A negative sweepAngle draws counterclockwise.

In use, addArc builds a portion of an ellipse defined by the specified oval and places it into the Path as a contiguous segment. This method is frequently used in custom drawing on Android canvases where paths are rendered with a Paint object. It is common to combine addArc with other Path methods to create complex shapes, such as rounded rectangles, spokes, or circular arcs for charts and diagrams.

Example: path.addArc(new RectF(0, 0, 100, 100), 0, 90) adds a quarter-circle arc starting at the rightmost point of the oval and sweeping to the bottom point.

See also: android.graphics.Path, Canvas, RectF.