const GLdouble*equation)

**eqn not supported**

*plane*- Specifies which clipping plane is being
positioned. Symbolic names of the form
**GL_CLIP_PLANE***i*, where*i*is an integer between 0 and**GL_MAX_CLIP_PLANES**$^-^1$, are accepted. *equation*- Specifies the address of an array of four double-precision floating-point values. These values are interpreted as a plane equation.

**glClipPlane** specifies a
half-space using a four-component plane equation. When **glClipPlane** is called,
*equation* is transformed by the inverse of the modelview matrix and stored
in the resulting eye coordinates. Subsequent changes to the modelview matrix
have no effect on the stored plane-equation components. If the dot product
of the eye coordinates of a vertex with the stored plane equation components
is positive or zero, the vertex is *in* with respect to that clipping plane.
Otherwise, it is *out*.

To enable and disable clipping planes, call **glEnable**
and **glDisable** with the argument **GL_CLIP_PLANE***i*, where *i* is the plane
number.

All clipping planes are initially defined as (0, 0, 0, 0) in eye coordinates and are disabled.

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