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GLFRONTFACE(3G)                                                                              GLFRONTFACE(3G)



NAME
       glFrontFace - define front- and back-facing polygons


C SPECIFICATION
       void glFrontFace( GLenum mode )


PARAMETERS
       mode  Specifies  the  orientation of front-facing polygons.  GL_CW and GL_CCW are accepted.  The ini-tial initial
             tial value is GL_CCW.

DESCRIPTION
       In a scene composed entirely of opaque closed  surfaces,  back-facing  polygons  are  never  visible.
       Eliminating  these  invisible  polygons  has  the obvious benefit of speeding up the rendering of the
       image.  To enable and disable elimination of back-facing polygons, call glEnable and  glDisable  with
       argument GL_CULL_FACE.

       The  projection  of a polygon to window coordinates is said to have clockwise winding if an imaginary
       object following the path from its first vertex, its second vertex, and so on, to  its  last  vertex,
       and  finally back to its first vertex, moves in a clockwise direction about the interior of the poly-gon. polygon.
       gon.  The polygon's winding is said to be counterclockwise if the imaginary object following the same
       path  moves in a counterclockwise direction about the interior of the polygon.  glFrontFace specifies
       whether polygons with clockwise winding in window coordinates, or counterclockwise winding in  window
       coordinates,  are taken to be front-facing.  Passing GL_CCW to mode selects counterclockwise polygons
       as front-facing; GL_CW selects clockwise polygons  as  front-facing.   By  default,  counterclockwise
       polygons are taken to be front-facing.

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

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

ASSOCIATED GETS
       glGet with argument GL_FRONT_FACE

SEE ALSO
       glCullFace(3G), glLightModel(3G)




                                                                                             GLFRONTFACE(3G)