Signature
Parameters
Variables  Description 

plane 
Specifies a clipping plane.
The number of clipping planes depends on the implementation,
but at least six clipping planes are supported.
They are identified by symbolic names of the form
GL_CLIP_PLANE
$\mathit{i}$
where i ranges from 0 to the value of
GL_MAX_CLIP_PLANES
 1.

equation 
Returns four doubleprecision values that are the coefficients of the plane equation of
plane
in eye coordinates.
The initial value is (0, 0, 0, 0).
