1GLMAPGRID(3G)                                                    GLMAPGRID(3G)
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NAME

6       glMapGrid1d,  glMapGrid1f,  glMapGrid2d, glMapGrid2f - define a one- or
7       two-dimensional mesh
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C SPECIFICATION

11       void glMapGrid1d( GLint un,
12                         GLdouble u1,
13                         GLdouble u2 )
14       void glMapGrid1f( GLint un,
15                         GLfloat u1,
16                         GLfloat u2 )
17       void glMapGrid2d( GLint un,
18                         GLdouble u1,
19                         GLdouble u2,
20                         GLint vn,
21                         GLdouble v1,
22                         GLdouble v2 )
23       void glMapGrid2f( GLint un,
24                         GLfloat u1,
25                         GLfloat u2,
26                         GLint vn,
27                         GLfloat v1,
28                         GLfloat v2 )
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PARAMETERS

32       un  Specifies the number of partitions in the grid range interval  [u1,
33           u2].  Must be positive.
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35       u1, u2
36           Specify the mappings for integer grid domain values i=0 and i=un.
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38       vn  Specifies  the number of partitions in the grid range interval [v1,
39           v2]
40           (glMapGrid2 only).
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42       v1, v2
43           Specify the mappings for integer grid domain values j=0 and j=vn
44           (glMapGrid2 only).
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DESCRIPTION

47       glMapGrid and glEvalMesh are used together to efficiently generate  and
48       evaluate a series of evenly-spaced map domain values.  glEvalMesh steps
49       through the integer domain of a one-  or  two-dimensional  grid,  whose
50       range  is  the  domain  of  the evaluation maps specified by glMap1 and
51       glMap2.
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53       glMapGrid1 and glMapGrid2 specify the linear grid mappings between  the
54       i  (or  i and j) integer grid coordinates, to the u (or u and v) float‐
55       ing-point evaluation  map  coordinates.   See  glMap1  and  glMap2  for
56       details of how u and v coordinates are evaluated.
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58       glMapGrid1  specifies  a  single  linear mapping such that integer grid
59       coordinate 0 maps exactly to u1, and integer grid  coordinate  un  maps
60       exactly to u2.  All other integer grid coordinates i are mapped so that
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62                                  u=i(u2−u1)/un+u1
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64       glMapGrid2  specifies  two such linear mappings.  One maps integer grid
65       coordinate i=0 exactly to u1, and integer grid coordinate i=un  exactly
66       to  u2.   The other maps integer grid coordinate j=0 exactly to v1, and
67       integer grid coordinate j=vn exactly to v2.  Other integer grid coordi‐
68       nates i and j are mapped such that
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70                                  u=i(u2−u1)/un+u1
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72                                  v=j(v2−v1)/vn+v1
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74       The  mappings specified by glMapGrid are used identically by glEvalMesh
75       and glEvalPoint.
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ERRORS

78       GL_INVALID_VALUE is generated if either un or vn is not positive.
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80       GL_INVALID_OPERATION is generated if glMapGrid is executed between  the
81       execution of glBegin and the corresponding execution of glEnd.
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ASSOCIATED GETS

84       glGet with argument GL_MAP1_GRID_DOMAIN
85       glGet with argument GL_MAP2_GRID_DOMAIN
86       glGet with argument GL_MAP1_GRID_SEGMENTS
87       glGet with argument GL_MAP2_GRID_SEGMENTS
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SEE ALSO

90       glEvalCoord(3G),     glEvalMesh(3G),    glEvalPoint(3G),    glMap1(3G),
91       glMap2(3G)
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95                                                                 GLMAPGRID(3G)