gluBeginSurface — delimit a NURBS surface definition
void gluBeginSurface( | GLUnurbs* | nurb); |
void gluEndSurface( | GLUnurbs* | nurb); |
Use gluBeginSurface to mark the beginning of a NURBS
surface definition. 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 GLU_MAP2_VERTEX_3 or GLU_MAP2_VERTEX_4.
To mark the end of the NURBS surface definition, call
gluEndSurface.
Trimming of NURBS surfaces is supported with gluBeginTrim, gluPwlCurve, gluNurbsCurve, and gluEndTrim. See the gluBeginTrim reference page for details.
GL evaluators are used to render the NURBS surface as a set of polygons.
Evaluator state is preserved during rendering
with glPushAttrib(GLU_EVAL_BIT) and
glPopAttrib.
See the glPushAttrib reference page for details on exactly what state
these calls preserve.
The following commands render a textured NURBS surface with normals; the texture coordinates and normals are also described as NURBS surfaces:
gluBeginSurface(nobj);
gluNurbsSurface(nobj, ..., GL_MAP2_TEXTURE_COORD_2);
gluNurbsSurface(nobj, ..., GL_MAP2_NORMAL);
gluNurbsSurface(nobj, ..., GL_MAP2_VERTEX_4);
gluEndSurface(nobj);
gluBeginCurve, gluBeginTrim, gluNewNurbsRenderer, gluNurbsCurve, gluNurbsSurface, gluPwlCurve, glPushAttrib
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