upstream-man-pages/man2/gluBeginCurve.xml

   1 <?xml version="1.0" encoding="UTF-8"?>
   2 <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN"
   3               "http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd">
   4 <refentry id="gluBeginCurve">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>1991-2006</year>
   9                 <holder>Silicon Graphics, Inc.</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>gluBeginCurve</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>gluBeginCurve</refname>
  17         <refpurpose>delimit a NURBS curve definition</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>C Specification</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>void <function>gluBeginCurve</function></funcdef>
  23                 <paramdef>GLUnurbs* <parameter>nurb</parameter></paramdef>
  24             </funcprototype>
  25         </funcsynopsis>
  26     </refsynopsisdiv>
  27     <refsynopsisdiv><title>C Specification</title>
  28         <funcsynopsis>
  29             <funcprototype>
  30                 <funcdef>void <function>gluEndCurve</function></funcdef>
  31                 <paramdef>GLUnurbs* <parameter>nurb</parameter></paramdef>
  32             </funcprototype>
  33         </funcsynopsis>
  34     </refsynopsisdiv>
  35     <!-- eqn: ignoring delim $$ -->
  36     <refsect1 id="parameters"><title>Parameters</title>
  37         <variablelist>
  38         <varlistentry>
  39             <term><parameter>nurb</parameter></term>
  40             <listitem>
  41                 <para>
  42                     Specifies the NURBS object (created with <citerefentry><refentrytitle>gluNewNurbsRenderer</refentrytitle></citerefentry>).
  43                 </para>
  44             </listitem>
  45         </varlistentry>
  46         </variablelist>
  47     </refsect1>
  48     <refsect1 id="description"><title>Description</title>
  49         <para>
  50             Use <function>gluBeginCurve</function> to mark the beginning of a NURBS
  51             curve definition.
  52             After
  53             calling <function>gluBeginCurve</function>, make one or more calls to
  54             <citerefentry><refentrytitle>gluNurbsCurve</refentrytitle></citerefentry> to define the attributes of the curve.
  55             Exactly one of the calls to <citerefentry><refentrytitle>gluNurbsCurve</refentrytitle></citerefentry> must have
  56             a curve type of <constant>GLU_MAP1_VERTEX_3</constant> or <constant>GLU_MAP1_VERTEX_4</constant>.
  57             To mark the end of the NURBS curve definition, call <citerefentry><refentrytitle>gluEndCurve</refentrytitle></citerefentry>.
  58         </para>
  59         <para>
  60             GL evaluators are used to render the NURBS curve as a series of line
  61             segments.
  62             Evaluator state is preserved during rendering
  63             with <citerefentry><refentrytitle>glPushAttrib</refentrytitle></citerefentry>(<constant>GLU_EVAL_BIT</constant>) and
  64             <citerefentry><refentrytitle>glPopAttrib</refentrytitle></citerefentry>().
  65             See the <citerefentry><refentrytitle>glPushAttrib</refentrytitle></citerefentry> reference page for details on exactly what state
  66             these calls preserve.
  67         </para>
  68     </refsect1>
  69     <refsect1 id="example"><title>Example</title>
  70         <para>
  71             The following commands render a textured NURBS curve with normals;
  72             texture coordinates and normals are also specified as NURBS curves:
  73             <programlisting>
  74 gluBeginCurve(nobj);
  75    gluNurbsCurve(nobj, ..., GL_MAP1_TEXTURE_COORD_2);
  76    gluNurbsCurve(nobj, ..., GL_MAP1_NORMAL);
  77    gluNurbsCurve(nobj, ..., GL_MAP1_VERTEX_4);
  78 gluEndCurve(nobj);
  79             </programlisting>
  80         </para>
  81     </refsect1>
  82     <refsect1 id="seealso"><title>See Also</title>
  83         <para>
  84             <citerefentry><refentrytitle>gluBeginSurface</refentrytitle></citerefentry>,
  85             <citerefentry><refentrytitle>gluBeginTrim</refentrytitle></citerefentry>,
  86             <citerefentry><refentrytitle>gluNewNurbsRenderer</refentrytitle></citerefentry>,
  87             <citerefentry><refentrytitle>gluNurbsCurve</refentrytitle></citerefentry>,
  88             <citerefentry><refentrytitle>glPopAttrib</refentrytitle></citerefentry>,
  89             <citerefentry><refentrytitle>glPushAttrib</refentrytitle></citerefentry>
  90         </para>
  91     </refsect1>
  92     <refsect1 id="Copyright"><title>Copyright</title>
  93         <para>
  94             Copyright <trademark class="copyright"></trademark> 1991-2006
  95             Silicon Graphics, Inc. This document is licensed under the SGI
  96             Free Software B License. For details, see
  97             <ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>.
  98         </para>
  99     </refsect1>
 100 </refentry>