gluBeginCurve(3G) OpenGL Reference gluBeginCurve(3G)NAME
gluBeginCurve, gluEndCurve - delimit a NURBS curve definition
C SPECIFICATION
void gluBeginCurve( GLUnurbs* nurb )
void gluEndCurve( GLUnurbs* nurb )
PARAMETERS
nurb Specifies the NURBS object (created with gluNewNurbsRenderer).
DESCRIPTION
Use gluBeginCurve to mark the beginning of a NURBS curve definition.
After calling gluBeginCurve, make one or more calls to gluNurbsCurve to
define the attributes of the curve. Exactly one of the calls to
gluNurbsCurve must have a curve type of GL_MAP1_VERTEX_3 or
GL_MAP1_VERTEX_4. To mark the end of the NURBS curve definition, call
gluEndCurve.
GL evaluators are used to render the NURBS curve as a series of line
segments. Evaluator state is preserved during rendering with
glPushAttrib(GL_EVAL_BIT) and glPopAttrib(). See the glPushAttrib
reference page for details on exactly what state these calls preserve.
EXAMPLE
The following commands render a textured NURBS curve with normals;
texture coordinates and normals are also specified as NURBS curves:
gluBeginCurve(nobj);
gluNurbsCurve(nobj, ..., GL_MAP1_TEXTURE_COORD_2);
gluNurbsCurve(nobj, ..., GL_MAP1_NORMAL);
gluNurbsCurve(nobj, ..., GL_MAP1_VERTEX_4);
gluEndCurve(nobj);
SEE ALSO
gluBeginSurface, gluBeginTrim, gluNewNurbsRenderer, gluNurbsCurve,
glPopAttrib, glPushAttrib
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