glShadeModel -- select flat or smooth shading
void glShadeModel(GLenum mode)
Specifies a symbolic value representing a shading technique.
Accepted values are GL_FLAT and GL_SMOOTH.
The default is GL_SMOOTH.
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
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.
Flat and smooth shading are specified by glShadeModel with mode
set to GL_FLAT and GL_SMOOTH, respectively.
GL_INVALID_ENUM is generated if mode is any value other
than GL_FLAT or GL_SMOOTH.
GL_INVALID_OPERATION is generated if glShadeModel is called
between a call to glBegin and the
corresponding call to glEnd.
glGet with argument
back to the OpenGL index page
© 1995 Uwe Behrens. All rights reserved.