1GLGETMAP(3G)                     OpenGL Manual                    GLGETMAP(3G)
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NAME

6       glGetMap - return evaluator parameters
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C SPECIFICATION

9       void glGetMapdv(GLenum target, GLenum query, GLdouble * v);
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11       void glGetMapfv(GLenum target, GLenum query, GLfloat * v);
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13       void glGetMapiv(GLenum target, GLenum query, GLint * v);
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PARAMETERS

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

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

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

73       GL_INVALID_ENUM is generated if either target or query is not an
74       accepted value.
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76       GL_INVALID_OPERATION is generated if glGetMap is executed between the
77       execution of glBegin() and the corresponding execution of glEnd().
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SEE ALSO

80       glEvalCoord(), glMap1(), glMap2()
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83       Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed
84       under the SGI Free Software B License. For details, see
85       http://oss.sgi.com/projects/FreeB/.
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AUTHORS

88       opengl.org
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92opengl.org                        07/13/2018                      GLGETMAP(3G)
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