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GLEVALPOINT()							 GLEVALPOINT()

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

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

       delim $$

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

       j  Specifies the	integer	value for grid domain  variable	 $j$  (glEval-
	  Point2 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 .	DELTA u	+ u );
				   1
       where

       DELTA u = (u - u	 ) / n
		   2   1

       and n, u	, and u
	       1       2

       are  the	 arguments to the most recent glMapGrid1 command.  The one ab-
       solute numeric requirement is that if $i~=~n$, then the value  computed
       from
       i . DELTA u + u	is exactly u .
		      1		    2

       In the two-dimensional case, glEvalPoint2, let
       DELTA u = (u  - u )/n
		   2	1

       DELTA v = (v  - v )/m
		   2	1

       where n,	u , u ,	m, v , and v
		 1   2	    1	    2

       are the arguments to the	most recent glMapGrid2 command.	 Then the glE-
       valPoint2 command is equivalent to calling

       glEvalCoord2(i .	 DELTA u + u , j . DELTA v + v );
				    1		      1

       The  only  absolute  numeric requirements are that if $i~=~n$, then the
       value computed from

       i . DELTA u + u	is exactly u ,
		      1		    2
       and if $j~=~m$, then the	value computed from

       j cdot DELTA v +	v  is exactly v	.
			 1	       2

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

SEE ALSO
       glEvalCoord, glEvalMesh,	glMap1,	glMap2,	glMapGrid

								 GLEVALPOINT()

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<https://man.freebsd.org/cgi/man.cgi?query=glEvalPoint2&sektion=3&manpath=FreeBSD+Ports+15.0.quarterly>

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