GLULOADSAMPLINGMATRMachTen Programmer’s GLULOADSAMPLINGMATRICES()

NAME
gluLoadSamplingMatrices - load NURBS sampling and culling
matrices

C SPECIFICATION
void gluLoadSamplingMatrices( GLUnurbs* nurb,
const GLfloat *model,
const GLfloat *perspective,
const GLint *view )

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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 gluNurb-
sProperty). 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 mod-
elview matrix, projection matrix, and viewport.)

SEE ALSO
gluGetNurbsProperty, gluNewNurbsRenderer, gluNurbsProperty

MachTen 1