void glFrontFace(GLenum mode)
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 frontfacing. By default, counterclockwise polygons are taken to be frontfacing.
GL_INVALID_OPERATION is generated if glFrontFace is called between a call to glBegin and the corresponding call to glEnd.
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© 1995 Uwe Behrens. All rights reserved.