upstream-man-pages/man2/xhtml/gluPartialDisk.xml

   1 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "xhtml1-transitional.dtd">
   2 <!-- saved from url=(0013)about:internet -->
   3 <?xml-stylesheet type="text/xsl" href="mathml.xsl"?><html xmlns="http://www.w3.org/1999/xhtml" xmlns:pref="http://www.w3.org/2002/Math/preference" pref:renderer="mathplayer-dl"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>gluPartialDisk</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="gluPartialDisk"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>gluPartialDisk — draw an arc of a disk</p></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">gluPartialDisk</b>(</code></td><td>GLUquadric*  </td><td><var class="pdparam">quad</var>, </td></tr><tr><td> </td><td>GLdouble  </td><td><var class="pdparam">inner</var>, </td></tr><tr><td> </td><td>GLdouble  </td><td><var class="pdparam">outer</var>, </td></tr><tr><td> </td><td>GLint  </td><td><var class="pdparam">slices</var>, </td></tr><tr><td> </td><td>GLint  </td><td><var class="pdparam">loops</var>, </td></tr><tr><td> </td><td>GLdouble  </td><td><var class="pdparam">start</var>, </td></tr><tr><td> </td><td>GLdouble  </td><td><var class="pdparam">sweep</var><code>)</code>;</td></tr></table></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="parameters"></a><h2>Parameters</h2><div class="variablelist"><dl><dt><span class="term"><em class="parameter"><code>quad</code></em></span></dt><dd><p>
   4                     Specifies a quadrics object (created with <a class="citerefentry" href="gluNewQuadric.xml"><span class="citerefentry"><span class="refentrytitle">gluNewQuadric</span></span></a>).
   5                 </p></dd><dt><span class="term"><em class="parameter"><code>inner</code></em></span></dt><dd><p>
   6                     Specifies the inner radius of the partial disk (can be 0).
   7                 </p></dd><dt><span class="term"><em class="parameter"><code>outer</code></em></span></dt><dd><p>
   8                     Specifies the outer radius of the partial disk.
   9                 </p></dd><dt><span class="term"><em class="parameter"><code>slices</code></em></span></dt><dd><p>
  10                     Specifies the number of subdivisions around the <span class="emphasis"><em>z</em></span> axis.
  11                 </p></dd><dt><span class="term"><em class="parameter"><code>loops</code></em></span></dt><dd><p>
  12                     Specifies the number of concentric rings about the origin into which
  13                     the partial disk is subdivided.
  14                 </p></dd><dt><span class="term"><em class="parameter"><code>start</code></em></span></dt><dd><p>
  15                     Specifies the starting angle, in degrees, of the disk portion.
  16                 </p></dd><dt><span class="term"><em class="parameter"><code>sweep</code></em></span></dt><dd><p>
  17                     Specifies the sweep angle, in degrees, of the disk portion.
  18                 </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
  19             <code class="function">gluPartialDisk</code> renders a partial disk on the
  20             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  21
  22                 <mml:mrow>
  23                     <mml:mi mathvariant="italic">z</mml:mi>
  24                     <mml:mo>=</mml:mo>
  25                     <mml:mn>0</mml:mn>
  26                 </mml:mrow>
  27             </mml:math>
  28             plane. A partial disk is
  29             similar to a full disk, except that only the subset of the disk from
  30             <em class="parameter"><code>start</code></em> through <em class="parameter"><code>start</code></em> + <em class="parameter"><code>sweep</code></em> is included (where 0 degrees is along the
  31             +\f2y\f axis,
  32             90 degrees along the +<span class="emphasis"><em>x</em></span> axis, 180 degrees along the \-<span class="emphasis"><em>y</em></span> axis, and
  33             270 degrees along the \-<span class="emphasis"><em>x</em></span> axis).
  34         </p><p>
  35             The partial disk has a radius of
  36             <em class="parameter"><code>outer</code></em> and contains a concentric circular hole with a radius
  37             of <em class="parameter"><code>inner</code></em>. If <em class="parameter"><code>inner</code></em> is 0, then no hole is generated. The partial disk is
  38             subdivided around the <span class="emphasis"><em>z</em></span> axis into slices (like pizza slices) and also
  39             about the <span class="emphasis"><em>z</em></span> axis into rings
  40             (as specified by <em class="parameter"><code>slices</code></em> and <em class="parameter"><code>loops</code></em>, respectively).
  41         </p><p>
  42             With respect to orientation, the +<span class="emphasis"><em>z</em></span>
  43             side of the partial disk is considered to
  44             be outside (see <a class="citerefentry" href="gluQuadricOrientation.xml"><span class="citerefentry"><span class="refentrytitle">gluQuadricOrientation</span></span></a>).
  45             This means that if the
  46             orientation is set to <code class="constant">GLU_OUTSIDE</code>, then any normals generated
  47             point along the +<span class="emphasis"><em>z</em></span> axis. Otherwise, they point along the \-<span class="emphasis"><em>z</em></span>
  48             axis.
  49         </p><p>
  50             If texturing is turned on (with <a class="citerefentry" href="gluQuadricTexture.xml"><span class="citerefentry"><span class="refentrytitle">gluQuadricTexture</span></span></a>), texture
  51             coordinates are generated
  52             linearly such that where
  53             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  54
  55                 <mml:mrow>
  56                     <mml:mi mathvariant="italic">r</mml:mi>
  57                     <mml:mo>=</mml:mo>
  58                     <mml:mi mathvariant="italic">outer</mml:mi>
  59                 </mml:mrow>
  60             </mml:math>,
  61             the value at (<span class="emphasis"><em>r</em></span>, 0, 0) is
  62             (1.0, 0.5), at (0, <span class="emphasis"><em>r</em></span>, 0) it is (0.5, 1.0), at (\-<span class="emphasis"><em>r</em></span>, 0, 0)
  63             it is (0.0, 0.5), and
  64             at (0, \-<span class="emphasis"><em>r</em></span>, 0) it is (0.5, 0.0).
  65         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
  66             <a class="citerefentry" href="gluCylinder.xml"><span class="citerefentry"><span class="refentrytitle">gluCylinder</span></span></a>,
  67             <a class="citerefentry" href="gluDisk.xml"><span class="citerefentry"><span class="refentrytitle">gluDisk</span></span></a>,
  68             <a class="citerefentry" href="gluNewQuadric.xml"><span class="citerefentry"><span class="refentrytitle">gluNewQuadric</span></span></a>,
  69             <a class="citerefentry" href="gluQuadricOrientation.xml"><span class="citerefentry"><span class="refentrytitle">gluQuadricOrientation</span></span></a>,
  70             <a class="citerefentry" href="gluQuadricTexture.xml"><span class="citerefentry"><span class="refentrytitle">gluQuadricTexture</span></span></a>,
  71             <a class="citerefentry" href="gluSphere.xml"><span class="citerefentry"><span class="refentrytitle">gluSphere</span></span></a>
  72         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
  73             Copyright <span class="trademark"></span>© 1991-2006
  74             Silicon Graphics, Inc. This document is licensed under the SGI
  75             Free Software B License. For details, see
  76             <a class="ulink" href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
  77         </p></div></div></body></html>