NAME    [Toc]    [Back]

       glGetMap,  glGetMapdv,  glGetMapfv,  glGetMapiv  -  return
       evaluator parameters

SYNOPSIS    [Toc]    [Back]

       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    [Toc]    [Back]

       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.  Specifies which  parameter  to  return.
       Symbolic  names  GL_COEFF,  GL_ORDER,  and  GL_DOMAIN  are
       accepted.  Returns the requested data.

DESCRIPTION    [Toc]    [Back]

       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: v returns the  control
  points  for  the evaluator function. One-dimensional
       evaluators return order  control  points,  and  two-dimensional
  evaluators  return  uorder  times  vorder  control
       points. Each control point consists of one, two, three, or
       four  integer, single-precision floating-point, or doubleprecision
 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.  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.  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    [Toc]    [Back]

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

ERRORS    [Toc]    [Back]

       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    [Toc]    [Back]

       glEvalCoord(3), glMap1(3), glMap2(3)



                                                     glGetMap(3G)