SbDPLine(3) on Linux
The text 55cae70e90d6, as Debian 6.0 (Squeeze) shipped it.
The SbDPLine class represents a line in 3D space. SbDPLine is used by many other classes in Coin. It provides a way of specifying a directed line (also known as a ray) through a specified point (origin) and a direction in 3D space. Note that the line is infinite in both directions from its definition point.