gluLoadSamplingMatrices - load NURBS sampling and culling
matrices
C SPECIFICATION
void gluLoadSamplingMatrices( GLUnurbs* nurb,
const GLfloat *model,
const GLfloat *perspective,
const GLint *view )
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 sam-
pling 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, gluNewNurbsRenderer, gluNurbsProperty
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