glShadeModel(3G)	       OpenGL Reference		      glShadeModel(3G)



NAME
     glShadeModel - select flat	or smooth shading


C SPECIFICATION
     void glShadeModel(	GLenum mode )


PARAMETERS
     mode  Specifies a symbolic	value representing a shading technique.
	   Accepted values are GL_FLAT and GL_SMOOTH.  The default is
	   GL_SMOOTH.


DESCRIPTION
     GL	primitives can have either flat	or smooth shading.  Smooth shading,
     the default, causes the computed colors of	vertices to be interpolated as
     the primitive is rasterized, typically assigning different	colors to each
     resulting pixel fragment.	Flat shading selects the computed color	of
     just one vertex and assigns it to all the pixel fragments generated by
     rasterizing a single primitive.  In either	case, the computed color of a
     vertex is the result of lighting, if lighting is enabled, or it is	the
     current color at the time the vertex was specified, if lighting is
     disabled.

     Flat and smooth shading are indistinguishable for points.	Counting
     vertices and primitives from one starting when glBegin is issued, each
     flat-shaded line segment i	is given the computed color of vertex i+1, its
     second vertex.  Counting similarly	from one, each flat-shaded polygon is
     given the computed	color of the vertex listed in the following table.
     This is the last vertex to	specify	the polygon in all cases except	single
     polygons, where the first vertex specifies	the flat-shaded	color.

		      ______________________________________
		      |____________________________|________|
		      |Single polygon (i=1)	   |   1    |
		      |Triangle	strip		   |  i+2   |
		      |Triangle	fan		   |  i+2   |
		      |Independent triangle	   |   3i   |
		      |Quad strip		   |  2i+2  |
		      |Independent quad		   |   4i   |
		      |____________________________|________|

     Flat and smooth shading are specified by glShadeModel with	mode set to
     GL_FLAT and GL_SMOOTH, respectively.

ERRORS
     GL_INVALID_ENUM is	generated if mode is any value other than GL_FLAT or
     GL_SMOOTH.






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glShadeModel(3G)	       OpenGL Reference		      glShadeModel(3G)



     GL_INVALID_OPERATION is generated if glShadeModel is executed between the
     execution of glBegin and the corresponding	execution of glEnd.

ASSOCIATED GETS
     glGet with	argument GL_SHADE_MODEL


SEE ALSO
     glBegin, glColor, glLight,	glLightModel














































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