1GLMAPGRID(3G) GLMAPGRID(3G)
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6 glMapGrid1d, glMapGrid1f, glMapGrid2d, glMapGrid2f - define a one- or
7 two-dimensional mesh
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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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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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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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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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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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90 glEvalCoord(3G), glEvalMesh(3G), glEvalPoint(3G), glMap1(3G),
91 glMap2(3G)
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95 GLMAPGRID(3G)