GLULOADSAMPLINGMATRICES(3gl)GLULOADSAMPLINGMATRICES(3gl)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 gluNewNurbsRen‐
derer).
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_TOL‐
ERANCE 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 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, gluNewNurbsRenderer, gluNurbsProperty
15 Mar 97 GLULOADSAMPLINGMATRICES(3gl)