OpenGL man pages
glGetClipPlane - return the coefficients of the specified clipping plane
void glGetClipPlane( GLenum plane,
GLdouble *equation )
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_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.
glGetClipPlane 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 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.
Fri Dec 6 11:18:03 EST 1996
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