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GLCLIPPLANE(3G)                                                                              GLCLIPPLANE(3G)



NAME
       glClipPlane - specify a plane against which all geometry is clipped


C SPECIFICATION
       void glClipPlane( GLenum plane,
                         const GLdouble *equation )


PARAMETERS
       plane     Specifies   which  clipping  plane  is  being  positioned.   Symbolic  names  of  the  form
                 GL_CLIP_PLANEi, where i is an integer between 0 and GL_MAX_CLIP_PLANES-1, are accepted.

       equation  Specifies the address of an array of four double-precision  floating-point  values.   These
                 values are interpreted as a plane equation.

DESCRIPTION
       Geometry is always clipped against the boundaries of a six-plane frustum in x, y, and z.  glClipPlane
       allows the specification of additional planes, not necessarily perpendicular to the x, y, or z  axis,
       against  which  all  geometry  is  clipped.   To  determine the maximum number of additional clipping
       planes, call glGetIntegerv with argument GL_MAX_CLIP_PLANES. All implementations support at least six
       such clipping planes.  Because the resulting clipping region is the intersection of the defined half-spaces, halfspaces,
       spaces, it is always convex.

       glClipPlane specifies a half-space using  a  four-component  plane  equation.   When  glClipPlane  is
       called,  equation  is  transformed by the inverse of the modelview matrix and stored in the resulting
       eye coordinates.  Subsequent changes to the modelview matrix have no effect on the stored plane-equa-tion plane-equation
       tion  components.   If the dot product of the eye coordinates of a vertex with the stored plane equa-tion equation
       tion components is positive or zero, the vertex is in with respect to that  clipping  plane.   Other-wise, Otherwise,
       wise, it is out.

       To  enable and disable clipping planes, call glEnable and glDisable with the argument GL_CLIP_PLANEi,
       where i is the plane number.

       All clipping planes are initially defined as (0, 0, 0, 0) in eye coordinates and are disabled.

NOTES
       It is always the case that GL_CLIP_PLANEi = GL_CLIP_PLANE0+i.

ERRORS
       GL_INVALID_ENUM is generated if plane is not an accepted value.

       GL_INVALID_OPERATION is generated if glClipPlane is executed between the execution of glBegin and the
       corresponding execution of glEnd.

ASSOCIATED GETS
       glGetClipPlane
       glIsEnabled with argument GL_CLIP_PLANEi

SEE ALSO
       glEnable(3G)




                                                                                             GLCLIPPLANE(3G)