- define a one- or two-dimensional mesh
C SPECIFICATION
PARAMETERS
_param1 Specifies the number of partitions in the grid
range interval [_param2, _param3]. Must be posi-
tive.
_param2, _param3
Specify the mappings for integer grid domain val-
ues i=0 and i=_eqnparam1.
_param4 Specifies the number of partitions in the grid
range interval [_param5, _param6]
(glMapGrid2 only).
_param5, _param6
Specify the mappings for integer grid domain val-
ues j=0 and j=_eqnparam4
(glMapGrid2 only).
DESCRIPTION
glMapGrid and glEvalMesh are used together to efficiently
generate and evaluate a series of evenly-spaced map domain
values. glEvalMesh steps through the integer domain of a
one- or two-dimensional grid, whose range is the domain of
the evaluation maps specified by glMap1 and glMap2.
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 coordi-
nates. 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 _param2, and
integer grid coordinate _param1 maps exactly to _param3.
All other integer grid coordinates i are mapped so that
u=i(_eqnparam3-_eqnparam2)/_eqnparam1+_eqnparam2
glMapGrid2 specifies two such linear mappings. One maps
integer grid coordinate i=0 exactly to _param2, and inte-
ger grid coordinate i=_eqnparam1 exactly to _param3. The
other maps integer grid coordinate j=0 exactly to _param5,
and integer grid coordinate j=_eqnparam4 exactly to
_param6. Other integer grid coordinates i and j are
mapped such that
u=i(_eqnparam3-_eqnparam2)/_eqnparam1+_eqnparam2
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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