GLULOADSAMPLINGMATRICES
Section: Misc. Reference Manual Pages (3G)
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NAME
gluLoadSamplingMatrices
- load NURBS sampling and culling matrices
C SPECIFICATION
void
gluLoadSamplingMatrices(
GLUnurbs*
nurb,
const GLfloat *model,
const GLfloat *perspective,
const GLint *view )
delim $$
PARAMETERS
- nurb
-
Specifies the NURBS object (created with gluNewNurbsRenderer).
- model
-
Specifies a modelview matrix (as from a glGetFloatv call).
- perspective
-
Specifies a projection matrix (as from a glGetFloatv call).
- view
-
Specifies a viewport (as from a glGetIntegerv call).
DESCRIPTION
gluLoadSamplingMatrices uses
model,
perspective, and
view to recompute the sampling and culling
matrices stored in
nurb.
The sampling matrix determines how finely a NURBS curve or surface
must be tessellated to satisfy the sampling tolerance (as determined by the
GLU_SAMPLING_TOLERANCE property).
The culling matrix is used in deciding if a NURBS curve or surface
should be culled before
rendering (when the
GLU_CULLING property is turned on).
gluLoadSamplingMatrices is necessary only if the GLU_AUTO_LOAD_MATRIX property is turned
off (see gluNurbsProperty).
Although it can be convenient to leave the GLU_AUTO_LOAD_MATRIX
property turned on, there can be a performance penalty for doing so.
(A round trip to the GL server is needed to fetch the current values
of the modelview matrix, projection matrix, and viewport.)
SEE ALSO
gluGetNurbsProperty(3G),
gluNewNurbsRenderer(3G),
gluNurbsProperty(3G)