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 initial 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 polygon. 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.

ASSOCIATED GETS

       glGet() with argument GL_FRONT_FACE

SEE ALSO

       glCullFace(),

COPYRIGHT

       Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI Free
       Software B License. For details, see http://oss.sgi.com/projects/FreeB/.

AUTHORS

       opengl.org