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NAMEglFrontFace - define front- and back-facing polygons
C SPECIFICATIONvoid f3glFrontFacefP( GLenum fImodefP )
DESCRIPTIONIn 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 %f3glEnablefP and %f3glDisablefP with argument %f3GL_CULL_FACEfP. 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. %f3glFrontFacefP specifies whether polygons with clockwise winding in window coordinates, or counterclockwise winding in window coordinates, are taken to be front-facing. Passing %f3GL_CCWfP to f2modefP selects counterclockwise polygons as front-facing; %f3GL_CWfP selects clockwise polygons as front-facing. By default, counterclockwise polygons are taken to be front-facing.
ERRORS%f3GL_INVALID_ENUMfP is generated if f2modefP is not an accepted value. %f3GL_INVALID_OPERATIONfP is generated if %f3glFrontFacefP is executed between the execution of %f3glBeginfP and the corresponding execution of %f3glEndfP.
ASSOCIATED GETS%f3glGetfP with argument %f3GL_FRONT_FACEfP
SEE ALSO%f3glCullFace(3G)fP, %f3glLightModel(3G)fP