upstream-doc/man2/gluPwlCurve.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="gluPwlCurve">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>1991-2006</year>
   9                 <holder>Silicon Graphics, Inc.</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>gluPwlCurve</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>gluPwlCurve</refname>
  17         <refpurpose>describe a piecewise linear NURBS trimming curve</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>C Specification</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>void <function>gluPwlCurve</function></funcdef>
  23                 <paramdef>GLUnurbs* <parameter>nurb</parameter></paramdef>
  24                 <paramdef>GLint <parameter>count</parameter></paramdef>
  25                 <paramdef>GLfloat* <parameter>data</parameter></paramdef>
  26                 <paramdef>GLint <parameter>stride</parameter></paramdef>
  27                 <paramdef>GLenum <parameter>type</parameter></paramdef>
  28             </funcprototype>
  29         </funcsynopsis>
  30     </refsynopsisdiv>
  31     <!-- eqn: ignoring delim $$ -->
  32     <refsect1 id="parameters"><title>Parameters</title>
  33         <variablelist>
  34         <varlistentry>
  35             <term><parameter>nurb</parameter></term>
  36             <listitem>
  37                 <para>
  38                     Specifies the NURBS object (created with <citerefentry><refentrytitle>gluNewNurbsRenderer</refentrytitle></citerefentry>).
  39                 </para>
  40             </listitem>
  41         </varlistentry>
  42         <varlistentry>
  43             <term><parameter>count</parameter></term>
  44             <listitem>
  45                 <para>
  46                     Specifies the number of points on the curve.
  47                 </para>
  48             </listitem>
  49         </varlistentry>
  50         <varlistentry>
  51             <term><parameter>data</parameter></term>
  52             <listitem>
  53                 <para>
  54                     Specifies an array containing the curve points.
  55                 </para>
  56             </listitem>
  57         </varlistentry>
  58         <varlistentry>
  59             <term><parameter>stride</parameter></term>
  60             <listitem>
  61                 <para>
  62                     Specifies the offset (a number of single-precision floating-point values)
  63                     between points on the curve.
  64                 </para>
  65             </listitem>
  66         </varlistentry>
  67         <varlistentry>
  68             <term><parameter>type</parameter></term>
  69             <listitem>
  70                 <para>
  71                     Specifies the type of curve.
  72                     Must be either <constant>GLU_MAP1_TRIM_2</constant> or <constant>GLU_MAP1_TRIM_3</constant>.
  73                 </para>
  74             </listitem>
  75         </varlistentry>
  76         </variablelist>
  77     </refsect1>
  78     <refsect1 id="description"><title>Description</title>
  79         <para>
  80             <function>gluPwlCurve</function> describes a piecewise linear trimming curve for a NURBS surface.
  81             A piecewise linear curve consists of a list of
  82             coordinates of points in the parameter space for the
  83             NURBS surface to be trimmed. These points are connected
  84             with line segments to form a curve. If the curve is
  85             an approximation to a curve that is not piecewise linear,
  86             the points should be close enough in parameter space that the
  87             resulting path appears curved at the resolution used in the application.
  88         </para>
  89         <para>
  90             If <parameter>type</parameter> is
  91             <constant>GLU_MAP1_TRIM_2</constant>, then it describes a curve in two-dimensional (<emphasis>u</emphasis>
  92             and <emphasis>v</emphasis>) parameter space. If it is <constant>GLU_MAP1_TRIM_3</constant>, then it
  93             describes a curve in two-dimensional homogeneous (<emphasis>u</emphasis>, <emphasis>v</emphasis>,
  94             and <emphasis>w</emphasis>) parameter space.
  95             See the <citerefentry><refentrytitle>gluBeginTrim</refentrytitle></citerefentry> reference page for more information
  96             about trimming curves.
  97         </para>
  98     </refsect1>
  99     <refsect1 id="notes"><title>Notes</title>
 100         <para>
 101             To describe a trim curve that closely follows the contours of a NURBS
 102             surface, call <citerefentry><refentrytitle>gluNurbsCurve</refentrytitle></citerefentry>.
 103         </para>
 104     </refsect1>
 105     <refsect1 id="seealso"><title>See Also</title>
 106         <para>
 107             <citerefentry><refentrytitle>gluBeginCurve</refentrytitle></citerefentry>,
 108             <citerefentry><refentrytitle>gluBeginTrim</refentrytitle></citerefentry>,
 109             <citerefentry><refentrytitle>gluNewNurbsRenderer</refentrytitle></citerefentry>,
 110             <citerefentry><refentrytitle>gluNurbsCurve</refentrytitle></citerefentry>
 111         </para>
 112     </refsect1>
 113     <refsect1 id="Copyright"><title>Copyright</title>
 114         <para>
 115             Copyright <trademark class="copyright"></trademark> 1991-2006
 116             Silicon Graphics, Inc. This document is licensed under the SGI
 117             Free Software B License. For details, see
 118             <ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>.
 119         </para>
 120     </refsect1>
 121 </refentry>