Class ThinLens

source code

ThinLens class.

This class represents thin lenses, which are specified only by their focal
lengths, diameter, position and orientation. Only the initializer and the
printing distinguishes thin lenses (in implementation) from other lenses.

Actions:
    * T on HR: 0
    * R on HR: + 1
    * T on AR: 0
    * R on AR: + 1

*=== Additional attributes with respect to the Optic class ===*

Focal: focal length of the lens  as given in initializer. [float]

*=== Name ===*

ThinLens

**Note**: the curvature of any surface is positive for a concave surface
(coating inside the sphere).
Thus kurv*HRNorm/|kurv| always points to the center
of the sphere of the surface, as is the convention for the lineSurfInter of
geometry module. Same for AR.

*******     HRK > 0 and ARK > 0     *******           HRK > 0 and ARK < 0
 *****                               ********         and |ARK| > |HRK|
 H***A                               H*********A
 *****                               ********
*******                             *******