(gl:map-grid-2 opengl nu u1 u2 nv v1 v2)


glMapGrid and glEvalMesh are used together to efficiently generate and evaluate a series of evenly-spaced mapdomain values.  glEvalMesh steps through the integer domain of a one- or two-dimensional grid, whose range isthe 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 coordi-nates, to the u (or u and v) floating-point evaluation map coordinates.  See glMap1 and glMap2 for details ofhow u and v coordinates are evaluated.glMapGrid1  specifies  a  single  linear  mapping such that integer grid coordinate 0 maps exactly to u1, andinteger grid coordinate un maps exactly to u2.  All other integer grid coordinates i are mapped so thatglMapGrid2 specifies two such linear mappings.  One maps integer grid coordinate i=0 exactly to u1, and inte-ger  grid coordinate i=un exactly to u2.  The other maps integer grid coordinate j=0 exactly to v1, and inte-ger grid coordinate j=vn exactly to v2.  Other integer grid coordinates i and j are mapped such that


             v1 -- integer number

             u1 -- integer number

         opengl -- opengl instance

             nu -- integer number

             nv -- integer number

             u2 -- integer number

             v2 -- integer number

Returns: boolean


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