public static class PdfCanvasConstants.LineJoinStyle
The line join style specifies the shape to be used at the corners of paths that are stroked. Join styles are significant only at points where consecutive segments of a path connect at an angle; segments that meet or intersect fortuitously receive no special treatment. All documentation for this class is taken from ISO 32000-1, section 18.104.22.168 "Line Join Style".
An arc of a circle with a diameter equal to the line width is drawn around the point where the two segments meet, connecting the outer edges of the strokes for the two segments. This pieslice-shaped figure is filled in, producing a rounded corner.