C SPECIFICATION

       void glMapGrid1d( GLint un,
                         GLdouble u1,
                         GLdouble u2 )
       void glMapGrid1f( GLint un,
                         GLfloat u1,
                         GLfloat u2 )
       void glMapGrid2d( GLint un,
                         GLdouble u1,
                         GLdouble u2,
                         GLint vn,
                         GLdouble v1,
                         GLdouble v2 )
       void glMapGrid2f( GLint un,
                         GLfloat u1,
                         GLfloat u2,
                         GLint vn,
                         GLfloat v1,
                         GLfloat v2 )

PARAMETERS

       un  Specifies the number of partitions in the grid range interval  [u1,
           u2].  Must be positive.

       u1, u2
           Specify the mappings for integer grid domain values i=0 and i=un.

       vn  Specifies  the number of partitions in the grid range interval [v1,
           v2]
           (glMapGrid2 only).

       v1, v2
           Specify the mappings for integer grid domain values j=0 and j=vn
           (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) float-
       ing-point evaluation  map  coordinates.   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 u1, and integer grid  coordinate  un  maps
       The mappings specified by glMapGrid are used identically by  glEvalMesh
       and glEvalPoint.

ERRORS

       GL_INVALID_VALUE is generated if either un or vn is not positive.

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

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(3G),    glEvalMesh(3G),    glEvalPoint(3G),     glMap1(3G),
       glMap2(3G)



                                                                 GLMAPGRID(3G)