glHint(3G)		       OpenGL Reference			    glHint(3G)



NAME
     glHint - specify implementation-specific hints


C SPECIFICATION
     void glHint( GLenum target,
		  GLenum mode )


PARAMETERS
     target  Specifies a symbolic constant indicating the behavior to be
	     controlled.  GL_FOG_HINT,	GL_LINE_SMOOTH_HINT,
	     GL_PERSPECTIVE_CORRECTION_HINT, GL_POINT_SMOOTH_HINT, and
	     GL_POLYGON_SMOOTH_HINT are	accepted.

     mode    Specifies a symbolic constant indicating the desired behavior.
	     GL_FASTEST, GL_NICEST, and	GL_DONT_CARE are accepted.

DESCRIPTION
     Certain aspects of	GL behavior, when there	is room	for interpretation,
     can be  controlled	with hints.  A hint is specified with two arguments.
     target is a symbolic constant indicating the behavior to be controlled,
     and mode is another symbolic constant indicating the desired behavior.
     mode can be one of	the following:

     GL_FASTEST		 The most efficient option should be chosen.

     GL_NICEST		 The most correct, or highest quality, option should
			 be chosen.

     GL_DONT_CARE	 The client doesn't have a preference.

     Though the	implementation aspects that can	be hinted are well defined,
     the interpretation	of the hints depends on	the implementation.  The hint
     aspects that can be specified with	target,	along with suggested
     semantics,	are as follows:

     GL_FOG_HINT	 Indicates the accuracy	of fog calculation.  If	per-
			 pixel fog calculation is not efficiently supported by
			 the GL	implementation,	hinting	GL_DONT_CARE or
			 GL_FASTEST can	result in per-vertex calculation of
			 fog effects.

     GL_LINE_SMOOTH_HINT Indicates the sampling	quality	of antialiased lines.
			 Hinting GL_NICEST can result in more pixel fragments
			 being generated during	rasterization, if a larger
			 filter	function is applied.

     GL_PERSPECTIVE_CORRECTION_HINT
			 Indicates the quality of color	and texture coordinate
			 interpolation.	 If perspective-corrected parameter
			 interpolation is not efficiently supported by the GL



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glHint(3G)		       OpenGL Reference			    glHint(3G)



			 implementation, hinting GL_DONT_CARE or GL_FASTEST
			 can result in simple linear interpolation of colors
			 and/or	texture	coordinates.

     GL_POINT_SMOOTH_HINT
			 Indicates the sampling	quality	of antialiased points.
			 Hinting GL_NICEST can result in more pixel fragments
			 being generated during	rasterization, if a larger
			 filter	function is applied.

     GL_POLYGON_SMOOTH_HINT
			 Indicates the sampling	quality	of antialiased
			 polygons.  Hinting GL_NICEST can result in more pixel
			 fragments being generated during rasterization, if a
			 larger	filter function	is applied.

NOTES
     The interpretation	of hints depends on the	implementation.	 glHint	can be
     ignored.

ERRORS
     GL_INVALID_ENUM is	generated if either target or mode is not an accepted
     value.

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





























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