Holding structure for a number of track rendering parameters.
Calculates path taking into account the parameters.
NOTE: Magnetic field direction convention is inverted.
This is decoupled from REveTrack/REveTrackList to allow sharing of the Propagator among several instances. Back references are kept so the tracks can be recreated when the parameters change.
REveTrackList has Get/Set methods for RnrStlye.
Enum EProjTrackBreaking_e and member fProjTrackBreaking specify whether 2D projected tracks get broken into several segments when the projected space consists of separate domains (like Rho-Z). The track-breaking is enabled by default.