glGetClipPlane Subroutine

OpenGL 1.1 for AIX: Reference Manual

Returns the coefficients of the clipping plane.

OpenGL C bindings library: libGL.a

void glGetClipPlane(GLenum Plane, 
        GLdouble *Equation)

Plane	Specifies a clipping plane. The number of clipping planes depends on the implementation; however, 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 glGetClipPlane subroutine returns in Equation the four coefficients of the plane equation for Plane.

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.

GL_INVALID_ENUM	Plane is not an accepted value.
GL_INVALID_OPERATION	The glGetClipPlane subroutine is called between a call to glBegin and the corresponding call to glEnd.

/usr/include/GL/gl.h

Contains C language constants, variable type definitions, and ANSI function prototypes for OpenGL.

The glBegin or glEnd subroutine, glClipPlane subroutine.