Index for Section 3G

Alphabetical listing for G

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glShadeModel(3G)
NAME
  glShadeModel - select flat or smooth shading

SYNOPSIS
  void glShadeModel(
	  GLenum mode );

PARAMETERS
  mode
      Specifies a symbolic value representing a shading technique. Accepted
      values are GL_FLAT and GL_SMOOTH. The initial value 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. Starting when
  glBegin() is issued and counting vertices and primitives from 1, the GL
  gives each flat-shaded line segment i the computed color of vertex i + 1,
  its second vertex. Counting similarly from 1, the GL gives each flat-shaded
  polygon 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.

  _____________________________________
  Primitive Type of Polygon i	Vertex
  _____________________________________
  Single polygon ( i == 1 )	1
  Triangle strip		i + 2
  Triangle fan			i + 2
  Independent triangle		 3 i
  Quad strip			2 i + 2
  Independent quad		 4 i
  _____________________________________

  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.

  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(3), glColor(3), glLight(3), glLightModel(3)

Index for Section 3G

Alphabetical listing for G

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