gluBeginSurface()gluBeginSurface()NAME
gluBeginSurface, gluEndSurface - delimit a NURBS surface definition
SYNOPSIS
void gluBeginSurface(
GLUnurbs* nurb ); void gluEndSurface(
GLUnurbs* nurb );
PARAMETERS
Specifies the NURBS object (created with gluNewNurbsRenderer).
DESCRIPTION
Use gluBeginSurface() to mark the beginning of a NURBS surface defini‐
tion. After calling gluBeginSurface(), make one or more calls to
gluNurbsSurface() to define the attributes of the surface. Exactly one
of these calls to gluNurbsSurface() must have a surface type of
GL_MAP2_VERTEX_3 or GL_MAP2_VERTEX_4. To mark the end of the NURBS sur‐
face definition, call gluEndSurface().
Trimming of NURBS surfaces is supported with gluBeginTrim(), gluPwl‐
Curve(), gluNurbsCurve(), and gluEndTrim(). See the gluBeginTrim() ref‐
erence page for details.
GL evaluators are used to render the NURBS surface as a set of poly‐
gons. Evaluator state is preserved during rendering with glPushAt‐
trib()(GL_EVAL_BIT) and glPopAttrib()(). See the glPushAttrib() refer‐
ence page for details on exactly what state these calls preserve.
EXAMPLE
The following commands render a textured NURBS surface with normals;
the texture coordinates and normals are also described as NURBS sur‐
faces: gluBeginSurface(nobj);
gluNurbsSurface(nobj, ..., GL_MAP2_TEXTURE_COORD_2);
gluNurbsSurface(nobj, ..., GL_MAP2_NORMAL);
gluNurbsSurface(nobj, ..., GL_MAP2_VERTEX_4); gluEndSurface(nobj);
SEE ALSOgluBeginCurve(3), gluBeginTrim(3), gluNewNurbsRenderer(3), gluNurb‐
sCurve(3), gluNurbsSurface(3), gluPwlCurve(3)gluBeginSurface()