1GLGETMAP(3G)                                                      GLGETMAP(3G)
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NAME

6       glGetMapdv, glGetMapfv, glGetMapiv - return evaluator parameters
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C SPECIFICATION

10       void glGetMapdv( GLenum target,
11                        GLenum query,
12                        GLdouble *v )
13       void glGetMapfv( GLenum target,
14                        GLenum query,
15                        GLfloat *v )
16       void glGetMapiv( GLenum target,
17                        GLenum query,
18                        GLint *v )
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PARAMETERS

22       target  Specifies  the  symbolic  name  of  a map.  Accepted values are
23               GL_MAP1_COLOR_4,         GL_MAP1_INDEX,         GL_MAP1_NORMAL,
24               GL_MAP1_TEXTURE_COORD_1,               GL_MAP1_TEXTURE_COORD_2,
25               GL_MAP1_TEXTURE_COORD_3,               GL_MAP1_TEXTURE_COORD_4,
26               GL_MAP1_VERTEX_3,       GL_MAP1_VERTEX_4,      GL_MAP2_COLOR_4,
27               GL_MAP2_INDEX,     GL_MAP2_NORMAL,     GL_MAP2_TEXTURE_COORD_1,
28               GL_MAP2_TEXTURE_COORD_2,               GL_MAP2_TEXTURE_COORD_3,
29               GL_MAP2_TEXTURE_COORD_4,         GL_MAP2_VERTEX_3,          and
30               GL_MAP2_VERTEX_4.
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32       query   Specifies  which parameter to return.  Symbolic names GL_COEFF,
33               GL_ORDER, and GL_DOMAIN are accepted.
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35       v       Returns the requested data.
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DESCRIPTION

38       glMap1 and glMap2 define evaluators.  glGetMap returns evaluator param‐
39       eters.  target chooses a map, query selects a specific parameter, and v
40       points to storage where the values will be returned.
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42       The acceptable values for the target parameter  are  described  in  the
43       glMap1 and glMap2 reference pages.
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45       query can assume the following values:
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47       GL_COEFF       v returns the control points for the evaluator function.
48                      One-dimensional evaluators return order control  points,
49                      and two-dimensional evaluators return uorder×vorder con‐
50                      trol points.  Each control point consists of  one,  two,
51                      three, or four integer, single-precision floating-point,
52                      or double-precision floating-point values, depending  on
53                      the  type  of  the evaluator.  The GL returns two-dimen‐
54                      sional control points in row-major  order,  incrementing
55                      the uorder index quickly and the vorder index after each
56                      row.  Integer values, when requested,  are  computed  by
57                      rounding the internal floating-point values to the near‐
58                      est integer values.
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60       GL_ORDER       v returns the order of  the  evaluator  function.   One-
61                      dimensional evaluators return a single value, order. The
62                      initial value is 1.  Two-dimensional  evaluators  return
63                      two values, uorder and vorder. The initial value is 1,1.
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65       GL_DOMAIN      v  returns  the linear u and v mapping parameters.  One-
66                      dimensional evaluators return two values, u1 and u2,  as
67                      specified  by glMap1.  Two-dimensional evaluators return
68                      four values (u1, u2, v1, and v2) as specified by glMap2.
69                      Integer values, when requested, are computed by rounding
70                      the internal floating-point values to the nearest  inte‐
71                      ger values.
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NOTES

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

77       GL_INVALID_ENUM  is  generated  if  either  target  or  query is not an
78       accepted value.
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80       GL_INVALID_OPERATION is generated if glGetMap is executed  between  the
81       execution of glBegin and the corresponding execution of glEnd.
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SEE ALSO

84       glEvalCoord(3G), glMap1(3G), glMap2(3G)
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88                                                                  GLGETMAP(3G)