- define a one- or two-dimensional mesh



C SPECIFICATION


PARAMETERS

       _param1  Specifies  the  number  of partitions in the grid
                range interval [_param2, _param3].  Must be posi-
                tive.

       _param2, _param3
                Specify the mappings for integer grid domain val-
                ues i=0 and i=_eqnparam1.

       _param4  Specifies the number of partitions  in  the  grid
                range interval [_param5, _param6]
                (glMapGrid2 only).

       _param5, _param6
                Specify the mappings for integer grid domain val-
                ues j=0 and j=_eqnparam4
                (glMapGrid2 only).


DESCRIPTION

       glMapGrid and glEvalMesh are used together to  efficiently
       generate and evaluate a series of evenly-spaced map domain
       values.  glEvalMesh steps through the integer domain of  a
       one- or two-dimensional grid, whose range is the domain of
       the evaluation maps specified by glMap1 and glMap2.

       glMapGrid1 and glMapGrid2 specify the linear grid mappings
       between  the  i  (or i and j) integer grid coordinates, to
       the u (or u and v) floating-point evaluation  map  coordi-
       nates.   See  glMap1 and glMap2 for details of how u and v
       coordinates are evaluated.

       glMapGrid1 specifies a single  linear  mapping  such  that
       integer  grid  coordinate  0  maps exactly to _param2, and
       integer grid coordinate _param1 maps exactly  to  _param3.
       All other integer grid coordinates i are mapped so that

            u=i(_eqnparam3-_eqnparam2)/_eqnparam1+_eqnparam2

       glMapGrid2  specifies  two such linear mappings.  One maps
       integer grid coordinate i=0 exactly to _param2, and  inte-
       ger  grid coordinate i=_eqnparam1 exactly to _param3.  The
       other maps integer grid coordinate j=0 exactly to _param5,
       and   integer  grid  coordinate  j=_eqnparam4  exactly  to
       _param6.  Other integer  grid  coordinates  i  and  j  are
       mapped such that

            u=i(_eqnparam3-_eqnparam2)/_eqnparam1+_eqnparam2

       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, glEvalPoint, glMap1, glMap2



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