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 dot DELTA(u) + u1 );
where

              DELTA(u) = ( u2 - u1 ) / n

and n, u1, and u2 are the arguments to the most recent glMapGrid1 command.

The one absolute numeric requirement is that if i=n, then the  value  computed
from i dot DELTA(u) + u1 is exactly u2.

In the two-dimensional case, glEvalPoint2, let

       DELTA(u) = ( u2 - u1 ) / n

       DELTA(v) = ( v2 - v1 ) / m,

where n, u1, u2, m, v1, and v2 are the arguments to the most recent glMapGrid2

command. Then the glEvalPoint2 command is equivalent to calling

       glEvalCoord2( i dot DELTA(u) + u1, j dot DELTA(v) + v1 );
The only absolute numeric requirements are that if i=n, then  the  value  com-
puted  from i dot DELTA(u) + u1 is exactly u2, and if j=m, then the value com-
puted from i dot DELTA(v) + v1 is exactly v2.

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