GLdouble *equation )

PARAMETERS
       plane     Specifies a clipping plane.  The number of clipping planes de‐
                 pends on the implementation, but at least six clipping  planes
                 are  supported.   They are identified by symbolic names of the
                 form GL_CLIP_PLANEi where 0 ≤ i < GL_MAX_CLIP_PLANES.

       equation  Returns four double-precision values that are the coefficients
                 of  the  plane equation of plane in eye coordinates.  The ini‐
                 tial value is (0, 0, 0, 0).

DESCRIPTION
       glGetClipPlane returns in equation the four coefficients  of  the  plane
       equation for plane.

NOTES
       It is always the case that GL_CLIP_PLANEi = GL_CLIP_PLANE0 + i.

       If an error is generated, no change is made to the contents of equation.

ERRORS
       GL_INVALID_ENUM is generated if plane is not an accepted value.

       GL_INVALID_OPERATION  is generated if glGetClipPlane is executed between
       the execution of glBegin and the corresponding execution of glEnd.

SEE ALSO
       glClipPlane

                                                             GLGETCLIPPLANE(3G)