gluLoadSamplingMatrices(3)

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 decid-
       ing 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 con-
       venient 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,  projec-
       tion matrix, and viewport.)

SEE ALSO

       gluGetNurbsProperty(3G), gluNewNurbsRenderer(3G), gluNurbsProperty(3G)

                                                   GLULOADSAMPLINGMATRICES(3G)