# glGetClipPlane.3G man page

glGetClipPlane — return the coefficients of the specified clipping plane

## C Specification

**void glGetClipPlane(GLenum ***plane***, GLdouble * ***equation***);**

## Parameters

*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**i where i ranges from 0 to the value of **GL_MAX_CLIP_PLANES** - 1.

*equation*

Returns four double-precision values that are the coefficients of the plane equation of *plane* in eye coordinates. The initial 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_PLANE**i = **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**()

## Copyright

Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.

## Authors

**opengl.org**