Index for Section 3G

Alphabetical listing for G

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glFrontFace(3G)
NAME
  glFrontFace - define front- and back-facing polygons

SYNOPSIS
  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.

  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(3), glLightModel(3)

Index for Section 3G

Alphabetical listing for G

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