(No version information available, might only be in Git)
Specifies how to render the endpoints of the path when stroking.
The default line cap style is CairoLineCap::BUTT.
CairoLineCap::BUTTStart(stop) the line exactly at the start(end) point
CairoLineCap::ROUNDUse a round ending, the center of the circle is the end point
CairoLineCap::SQUAREUse squared ending, the center of the square is the end point