HP b2600 Reference Manual page 284

M
glMapGrid
glMapGrid1 and glMapGrid2 specify the linear grid mappings between the i (or i and j)
integer grid coordinates, to the u (or u and v) floating-point evaluation map coordinates.
See glMap1 and glMap2 for details of how u and v coordinates are evaluated.
glMapGrid1 specifies a single linear mapping such that integer grid coordinate 0 maps
exactly to u1, and integer grid coordinate un maps exactly to u2. All other integer grid
coordinates i are mapped so that
u = i (u2 u1) / un + u1
glMapGrid2 specifies two such linear mappings. One maps integer grid coordinate i=0
exactly to u1, and integer grid coordinate i=un exactly to u2. The other maps integer grid
coordinate j=0 exactly to v1, and integer grid coordinate j=vn exactly to v2. Other integer
grid coordinates i and j are mapped such that
u = i (u2 u1) / un + u1
v = j (v2 v1) / vn + v1
The mappings specified by glMapGrid are used identically by glEvalMesh and
glEvalPoint.
Errors
•
•
Associated Gets
glGet with argument GL_MAP1_GRID_DOMAIN
glGet with argument GL_MAP2_GRID_DOMAIN
glGet with argument GL_MAP1_GRID_SEGMENTS
glGet with argument GL_MAP2_GRID_SEGMENTS
See Also
glEvalCoord,
glEvalMesh,
glEvalPoint,
glMap1,
glMap2
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GL_INVALID_VALUE is generated if either un or vn is not positive.
GL_INVALID_OPERATION is generated if glMapGrid is executed between the
execution of glBegin and the corresponding execution of glEnd.
Chapter 11