1GLFRONTFACE(3G)                  OpenGL Manual                 GLFRONTFACE(3G)
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NAME

6       glFrontFace - define front- and back-facing polygons
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C SPECIFICATION

9       void glFrontFace(GLenum mode);
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PARAMETERS

12       mode
13           Specifies the orientation of front-facing polygons.  GL_CW and
14           GL_CCW are accepted. The initial value is GL_CCW.
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DESCRIPTION

17       In a scene composed entirely of opaque closed surfaces, back-facing
18       polygons are never visible. Eliminating these invisible polygons has
19       the obvious benefit of speeding up the rendering of the image. To
20       enable and disable elimination of back-facing polygons, call glEnable()
21       and glDisable() with argument GL_CULL_FACE.
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23       The projection of a polygon to window coordinates is said to have
24       clockwise winding if an imaginary object following the path from its
25       first vertex, its second vertex, and so on, to its last vertex, and
26       finally back to its first vertex, moves in a clockwise direction about
27       the interior of the polygon. The polygon's winding is said to be
28       counterclockwise if the imaginary object following the same path moves
29       in a counterclockwise direction about the interior of the polygon.
30       glFrontFace specifies whether polygons with clockwise winding in window
31       coordinates, or counterclockwise winding in window coordinates, are
32       taken to be front-facing. Passing GL_CCW to mode selects
33       counterclockwise polygons as front-facing; GL_CW selects clockwise
34       polygons as front-facing. By default, counterclockwise polygons are
35       taken to be front-facing.
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ERRORS

38       GL_INVALID_ENUM is generated if mode is not an accepted value.
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ASSOCIATED GETS

41       glGet() with argument GL_FRONT_FACE
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SEE ALSO

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

52       opengl.org
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56opengl.org                        06/10/2014                   GLFRONTFACE(3G)
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