GLULOADSAMPLINGMATRICUNIXGProgrammer'sGLULOADSAMPLINGMATRICES(3G)
NAME
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 glGet-
Floatv call).
perspective Specifies a projection matrix (as from a glGet-
Floatv 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 toler-
ance (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 model-
view matrix, projection matrix, and viewport.)
SEE ALSO
gluGetNurbsProperty(3G), gluNewNurbsRenderer(3G),
gluNurbsProperty(3G)
MirBSD #10-current Printed 2021-12-07 1