1GLMAPGRID(3G)                    OpenGL Manual                   GLMAPGRID(3G)
2
3
4

NAME

6       glMapGrid - define a one- or two-dimensional mesh
7

C SPECIFICATION

9       void glMapGrid1d(GLint un, GLdouble u1, GLdouble u2);
10
11       void glMapGrid1f(GLint un, GLfloat u1, GLfloat u2);
12
13       void glMapGrid2d(GLint un, GLdouble u1, GLdouble u2, GLint vn,
14                        GLdouble v1, GLdouble v2);
15
16       void glMapGrid2f(GLint un, GLfloat u1, GLfloat u2, GLint vn,
17                        GLfloat v1, GLfloat v2);
18

PARAMETERS

20       un
21           Specifies the number of partitions in the grid range interval [u1,
22           u2]. Must be positive.
23
24       u1, u2
25           Specify the mappings for integer grid domain values i = 0 and i =
26           un.
27
28       vn
29           Specifies the number of partitions in the grid range interval [v1,
30           v2] (glMapGrid2 only).
31
32       v1, v2
33           Specify the mappings for integer grid domain values j = 0 and j =
34           vn (glMapGrid2 only).
35

DESCRIPTION

37       glMapGrid and glEvalMesh() are used together to efficiently generate
38       and evaluate a series of evenly-spaced map domain values.  glEvalMesh()
39       steps through the integer domain of a one- or two-dimensional grid,
40       whose range is the domain of the evaluation maps specified by glMap1()
41       and glMap2().
42
43       glMapGrid1 and glMapGrid2 specify the linear grid mappings between the
44       i (or i and j) integer grid coordinates, to the u (or u and v)
45       floating-point evaluation map coordinates. See glMap1() and glMap2()
46       for details of how u and v coordinates are evaluated.
47
48       glMapGrid1 specifies a single linear mapping such that integer grid
49       coordinate 0 maps exactly to u1, and integer grid coordinate un maps
50       exactly to u2. All other integer grid coordinates i are mapped so that
51
52       u = i ⁡ u2 - u1 un + u1
53
54       glMapGrid2 specifies two such linear mappings. One maps integer grid
55       coordinate i = 0 exactly to u1, and integer grid coordinate i = un
56       exactly to u2. The other maps integer grid coordinate j = 0 exactly to
57       v1, and integer grid coordinate j = vn exactly to v2. Other integer
58       grid coordinates i and j are mapped such that
59
60       u = i ⁡ u2 - u1 un + u1
61
62       v = j ⁡ v2 - v1 vn + v1
63
64       The mappings specified by glMapGrid are used identically by
65       glEvalMesh() and glEvalPoint().
66

ERRORS

68       GL_INVALID_VALUE is generated if either un or vn is not positive.
69
70       GL_INVALID_OPERATION is generated if glMapGrid is executed between the
71       execution of glBegin() and the corresponding execution of glEnd().
72

ASSOCIATED GETS

74       glGet() with argument GL_MAP1_GRID_DOMAIN
75
76       glGet() with argument GL_MAP2_GRID_DOMAIN
77
78       glGet() with argument GL_MAP1_GRID_SEGMENTS
79
80       glGet() with argument GL_MAP2_GRID_SEGMENTS
81

SEE ALSO

83       glEvalCoord(), glEvalMesh(), glEvalPoint(), glMap1(), glMap2()
84

86       Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed
87       under the SGI Free Software B License. For details, see
88       http://oss.sgi.com/projects/FreeB/.
89

AUTHORS

91       opengl.org
92
93
94
95opengl.org                        06/10/2014                     GLMAPGRID(3G)
Impressum