HP Workstation zx2000 OpenGL 1.1 Reference for HP-UX 11.x - Page 187

G glXGetClipPlane glXGetClipPlane glGetClipPlane: return the coefficients of the specified clipping plane. C Specification void glGetClipPlane( GLenum plane, GLdouble *equation) Parameters plane equation 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. 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_PLANEi = 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 Chapter 7 187