upstream-man-pages/man2/gluDisk.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="gluDisk">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>1991-2006</year>
   9                 <holder>Silicon Graphics, Inc.</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>gluDisk</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>gluDisk</refname>
  17         <refpurpose>draw a disk</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>C Specification</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>void <function>gluDisk</function></funcdef>
  23                 <paramdef>GLUquadric* <parameter>quad</parameter></paramdef>
  24                 <paramdef>GLdouble <parameter>inner</parameter></paramdef>
  25                 <paramdef>GLdouble <parameter>outer</parameter></paramdef>
  26                 <paramdef>GLint <parameter>slices</parameter></paramdef>
  27                 <paramdef>GLint <parameter>loops</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>quad</parameter></term>
  36             <listitem>
  37                 <para>
  38                     Specifies the quadrics object (created with <citerefentry><refentrytitle>gluNewQuadric</refentrytitle></citerefentry>).
  39                 </para>
  40             </listitem>
  41         </varlistentry>
  42         <varlistentry>
  43             <term><parameter>inner</parameter></term>
  44             <listitem>
  45                 <para>
  46                     Specifies the inner radius of the disk (may be 0).
  47                 </para>
  48             </listitem>
  49         </varlistentry>
  50         <varlistentry>
  51             <term><parameter>outer</parameter></term>
  52             <listitem>
  53                 <para>
  54                     Specifies the outer radius of the disk.
  55                 </para>
  56             </listitem>
  57         </varlistentry>
  58         <varlistentry>
  59             <term><parameter>slices</parameter></term>
  60             <listitem>
  61                 <para>
  62                     Specifies the number of subdivisions around the <emphasis>z</emphasis> axis.
  63                 </para>
  64             </listitem>
  65         </varlistentry>
  66         <varlistentry>
  67             <term><parameter>loops</parameter></term>
  68             <listitem>
  69                 <para>
  70                     Specifies the number of concentric rings about the origin into which
  71                     the disk is subdivided.
  72                 </para>
  73             </listitem>
  74         </varlistentry>
  75         </variablelist>
  76     </refsect1>
  77     <refsect1 id="description"><title>Description</title>
  78         <para>
  79             <function>gluDisk</function> renders a disk on the <emphasis>z</emphasis> = 0 plane. The disk has a radius of
  80             <parameter>outer</parameter> and contains a concentric circular hole with a radius
  81             of <parameter>inner</parameter>. If <parameter>inner</parameter> is 0, then no hole is generated. The disk is
  82             subdivided around the <emphasis>z</emphasis> axis into slices (like pizza slices) and also
  83             about the <emphasis>z</emphasis> axis into rings
  84             (as specified by <parameter>slices</parameter> and <parameter>loops</parameter>, respectively).
  85         </para>
  86         <para>
  87             With respect to orientation, the +<emphasis>z</emphasis> side of the disk is considered to be
  88             ``outside'' (see <citerefentry><refentrytitle>gluQuadricOrientation</refentrytitle></citerefentry>).
  89             This means that if the
  90             orientation is set to <constant>GLU_OUTSIDE</constant>, then any normals generated
  91             point along the +<emphasis>z</emphasis> axis. Otherwise, they point along the \-<emphasis>z</emphasis>
  92             axis.
  93         </para>
  94         <para>
  95             If texturing has been turned on (with <citerefentry><refentrytitle>gluQuadricTexture</refentrytitle></citerefentry>),
  96             texture coordinates are generated
  97             linearly such that where
  98             <inlineequation><mml:math>
  99                 <!-- eqn: r  =  outer:-->
 100                 <mml:mrow>
 101                     <mml:mi mathvariant="italic">r</mml:mi>
 102                     <mml:mo>=</mml:mo>
 103                     <mml:mi mathvariant="italic">outer</mml:mi>
 104                 </mml:mrow>
 105             </mml:math></inlineequation>,
 106             the value at (<emphasis>r</emphasis>, 0, 0) is
 107             (1, 0.5), at (0, <emphasis>r</emphasis>, 0) it is (0.5, 1), at (\-<emphasis>r</emphasis>, 0, 0)
 108             it is (0, 0.5), and
 109             at (0, \-<emphasis>r</emphasis>, 0) it is (0.5, 0).
 110         </para>
 111     </refsect1>
 112     <refsect1 id="seealso"><title>See Also</title>
 113         <para>
 114             <citerefentry><refentrytitle>gluCylinder</refentrytitle></citerefentry>,
 115             <citerefentry><refentrytitle>gluNewQuadric</refentrytitle></citerefentry>,
 116             <citerefentry><refentrytitle>gluPartialDisk</refentrytitle></citerefentry>,
 117             <citerefentry><refentrytitle>gluQuadricOrientation</refentrytitle></citerefentry>,
 118             <citerefentry><refentrytitle>gluQuadricTexture</refentrytitle></citerefentry>,
 119             <citerefentry><refentrytitle>gluSphere</refentrytitle></citerefentry>
 120         </para>
 121     </refsect1>
 122     <refsect1 id="Copyright"><title>Copyright</title>
 123         <para>
 124             Copyright <trademark class="copyright"></trademark> 1991-2006
 125             Silicon Graphics, Inc. This document is licensed under the SGI
 126             Free Software B License. For details, see
 127             <ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>.
 128         </para>
 129     </refsect1>
 130 </refentry>