gluLoadSamplingMatrices.3G - Man Page

void gluLoadSamplingMatrices( GLUnurbs* nurb,

	const GLfloat *model,
	const GLfloat *perspective,
	const GLint *view )

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).

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 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.)

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

gluNurbsProperty.3G(3).