glGetClipPlane Subroutine

OpenGL 1.2 for AIX: Reference Manual

Returns the coefficients of the clipping plane.

OpenGL C bindings library: libGL.a

void glGetClipPlane(GLenum Plane, 
        GLdouble *Equation)

The glGetClipPlane subroutine returns in Equation the four coefficients of the plane equation for Plane.

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.

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.