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GLGETMAP(3G)                                                                                    GLGETMAP(3G)



NAME
       glGetMapdv, glGetMapfv, glGetMapiv - return evaluator parameters


C SPECIFICATION
       void glGetMapdv( GLenum target,
                        GLenum query,
                        GLdouble *v )
       void glGetMapfv( GLenum target,
                        GLenum query,
                        GLfloat *v )
       void glGetMapiv( GLenum target,
                        GLenum query,
                        GLint *v )


PARAMETERS
       target  Specifies  the  symbolic  name of a map.  Accepted values are GL_MAP1_COLOR_4, GL_MAP1_INDEX,
               GL_MAP1_NORMAL,  GL_MAP1_TEXTURE_COORD_1,  GL_MAP1_TEXTURE_COORD_2,  GL_MAP1_TEXTURE_COORD_3,
               GL_MAP1_TEXTURE_COORD_4,  GL_MAP1_VERTEX_3, GL_MAP1_VERTEX_4, GL_MAP2_COLOR_4, GL_MAP2_INDEX,
               GL_MAP2_NORMAL,  GL_MAP2_TEXTURE_COORD_1,  GL_MAP2_TEXTURE_COORD_2,  GL_MAP2_TEXTURE_COORD_3,
               GL_MAP2_TEXTURE_COORD_4, GL_MAP2_VERTEX_3, and GL_MAP2_VERTEX_4.

       query   Specifies  which  parameter  to return.  Symbolic names GL_COEFF, GL_ORDER, and GL_DOMAIN are
               accepted.

       v       Returns the requested data.

DESCRIPTION
       glMap1 and glMap2 define evaluators.  glGetMap returns evaluator parameters.  target chooses  a  map,
       query selects a specific parameter, and v points to storage where the values will be returned.

       The  acceptable  values  for  the  target  parameter are described in the glMap1 and glMap2 reference
       pages.

       query can assume the following values:

       GL_COEFF       v returns the control points for the evaluator function.   One-dimensional  evaluators
                      return  order  control  points,  and two-dimensional evaluators return uorder * vorder
                      control points.  Each control point consists of one, two, three, or four integer, sin-gle-precision single-precision
                      gle-precision  floating-point, or double-precision floating-point values, depending on
                      the type of the evaluator.  The GL returns two-dimensional control points in row-major
                      order,  incrementing  the  uorder  index  quickly and the vorder index after each row.
                      Integer values, when requested, are computed by rounding the  internal  floating-point
                      values to the nearest integer values.

       GL_ORDER       v  returns  the  order of the evaluator function.  One-dimensional evaluators return a
                      single value, order. The initial value is 1.  Two-dimensional  evaluators  return  two
                      values, uorder and vorder. The initial value is 1,1.

       GL_DOMAIN      v  returns  the  linear u and v mapping parameters.  One-dimensional evaluators return
                      two values, u1 and u2, as specified by glMap1.  Two-dimensional evaluators return four
                      values  (u1,  u2, v1, and v2) as specified by glMap2.  Integer values, when requested,
                      are computed by rounding the internal floating-point values  to  the  nearest  integer
                      values.

NOTES
       If an error is generated, no change is made to the contents of v.

ERRORS
       GL_INVALID_ENUM is generated if either target or query is not an accepted value.

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

SEE ALSO
       glEvalCoord(3G), glMap1(3G), glMap2(3G)




                                                                                                GLGETMAP(3G)