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     <STRONG>NAME</STRONG>
	  <STRONG>glPolygonOffset</STRONG> - set	the scale and units used to calculate
	  depth	values


     <STRONG>C</STRONG> <STRONG>SPECIFICATION</STRONG>
	  void <STRONG>glPolygonOffset</STRONG>(	GLfloat	<EM>factor</EM>,
				GLfloat	<EM>units</EM> )


     <STRONG>PARAMETERS</STRONG>
	  <EM>factor</EM>  Specifies a scale factor that	is used	to create a
		  variable depth offset	for each polygon. The initial
		  value	is 0.

	  <EM>units</EM>	  Is multiplied	by an implementation-specific value to
		  create a constant depth offset. The initial value is
		  0.

     <STRONG>DESCRIPTION</STRONG>
	  When <STRONG>GL_POLYGON_OFFSET</STRONG> is enabled, each fragment's <EM>depth</EM>
	  value	will be	offset after it	is interpolated	from the <EM>depth</EM>
	  values of the	appropriate vertices.  The value of the	offset
	  is factor * DZ  +  r * units,	where DZ  is a measurement of
	  the change in	depth relative to the screen area of the
	  polygon, and r is the	smallest value that is guaranteed to
	  produce a resolvable offset for a given implementation.  The
	  offset is added before the depth test	is performed and
	  before the value is written into the depth buffer.

	  <STRONG>glPolygonOffset</STRONG> is useful for	rendering hidden-line images,
	  for applying decals to surfaces, and for rendering solids
	  with highlighted edges.

     <STRONG>NOTES</STRONG>
	  <STRONG>glPolygonOffset</STRONG> is available only if the GL version is 1.1
	  or greater.

	  <STRONG>glPolygonOffset</STRONG> has no effect	on depth coordinates placed in
	  the feedback buffer.

	  <STRONG>glPolygonOffset</STRONG> has no effect	on selection.

     <STRONG>ERRORS</STRONG>
	  <STRONG>GL_INVALID_OPERATION</STRONG> is generated if <STRONG>glPolygonOffset</STRONG> is
	  executed between the execution of <STRONG>glBegin</STRONG> and	the
	  corresponding	execution of <STRONG>glEnd</STRONG>.

     <STRONG>ASSOCIATED</STRONG>	<STRONG>GETS</STRONG>
	  <STRONG>glIsEnabled</STRONG> with argument <STRONG>GL_POLYGON_OFFSET_FILL</STRONG>,
	  <STRONG>GL_POLYGON_OFFSET_LINE</STRONG>, or <STRONG>GL_POLYGON_OFFSET_POINT</STRONG>.

	  <STRONG>glGet</STRONG>	with argument <STRONG>GL_POLYGON_OFFSET_FACTOR</STRONG> or
	  <STRONG>GL_POLYGON_OFFSET_UNITS</STRONG>.

     <STRONG>SEE</STRONG> <STRONG>ALSO</STRONG>
	  <STRONG>glDepthFunc</STRONG>, <STRONG>glDisable</STRONG>, <STRONG>glEnable</STRONG>, <STRONG>glGet</STRONG>, <STRONG>glIsEnabled</STRONG>,
	  <STRONG>glLineWidth</STRONG>, <STRONG>glStencilOp</STRONG>, <STRONG>glTexEnv</STRONG>














































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