glEvalPoint(3G)		       OpenGL Reference		       glEvalPoint(3G)



NAME
     glEvalPoint1, glEvalPoint2	- generate and evaluate	a single point in a
     mesh


C SPECIFICATION
     void glEvalPoint1(	GLint i	)
     void glEvalPoint2(	GLint i,
			GLint j	)


PARAMETERS
     i	Specifies the integer value for	grid domain variable i.

     j	Specifies the integer value for	grid domain variable j (glEvalPoint2
	only).

DESCRIPTION
     glMapGrid and glEvalMesh are used in tandem to efficiently	generate and
     evaluate a	series of evenly spaced	map domain values.  glEvalPoint	can be
     used to evaluate a	single grid point in the same gridspace	that is
     traversed by glEvalMesh.  Calling glEvalPoint1 is equivalent to calling

				glEvalCoord1(i.Wu + u );
						     1
				      where

				  Wu = (u -u )/n
					 2  1

     and n, u ,	and u  are the arguments to the	most recent glMapGrid1
     command.1 The one absolute	numeric	requirement is that if i = n, then the
     value computed from i.Wu +	u  is exactly u	.
				 1	       2
     In	the two-dimensional case, glEvalPoint2,	let

				   Wu=(u -u )/n
					2  1
				   Wv=(v -v )/m
					2  1
     where n, u	, u , m, v , and v  are	the arguments to the most recent
     glMapGrid21command.  Then the2glEvalPoint2	command	is equivalent to
     calling

			  glEvalCoord2(i.Wu + u	, j.Wv + v );
					       1	  1
     The only absolute numeric requirements are	that if	i = n, then the	value
     computed from i.Wu	+ u  is	exactly	u , and	if j = m, then the value
     computed from j.Wv	+ v1 is	exactly	v2.
			   1		 2





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glEvalPoint(3G)		       OpenGL Reference		       glEvalPoint(3G)



ASSOCIATED GETS
     glGet with	argument GL_MAP1_GRID_DOMAIN
     glGet with	argument GL_MAP2_GRID_DOMAIN
     glGet with	argument GL_MAP1_GRID_SEGMENTS
     glGet with	argument GL_MAP2_GRID_SEGMENTS


MACHINE	DEPENDENCIES
     RealityEngine, RealityEngine2, and	VTX systems do not handle 1D maps for
     colors correctly.


SEE ALSO
     glEvalCoord, glEvalMesh, glMap1, glMap2, glMapGrid









































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