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

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   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>gluUnProject</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="gluUnProject"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>gluUnProject — map window coordinates to object coordinates</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">GLint <b class="fsfunc">gluUnProject</b>(</code></td><td>GLdouble  </td><td><var class="pdparam">winX</var>, </td></tr><tr><td> </td><td>GLdouble  </td><td><var class="pdparam">winY</var>, </td></tr><tr><td> </td><td>GLdouble  </td><td><var class="pdparam">winZ</var>, </td></tr><tr><td> </td><td>const GLdouble *  </td><td><var class="pdparam">model</var>, </td></tr><tr><td> </td><td>const GLdouble *  </td><td><var class="pdparam">proj</var>, </td></tr><tr><td> </td><td>const GLint *  </td><td><var class="pdparam">view</var>, </td></tr><tr><td> </td><td>GLdouble*  </td><td><var class="pdparam">objX</var>, </td></tr><tr><td> </td><td>GLdouble*  </td><td><var class="pdparam">objY</var>, </td></tr><tr><td> </td><td>GLdouble*  </td><td><var class="pdparam">objZ</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>winX</code></em>, </span><span class="term"><em class="parameter"><code>winY</code></em>, </span><span class="term"><em class="parameter"><code>winZ</code></em></span></dt><dd><p>
   4                     Specify the window coordinates to be mapped.
   5                 </p></dd><dt><span class="term"><em class="parameter"><code>model</code></em></span></dt><dd><p>
   6                     Specifies the modelview matrix (as from a <a class="citerefentry" href="glGetDoublev.xml"><span class="citerefentry"><span class="refentrytitle">glGetDoublev</span></span></a> call).
   7                 </p></dd><dt><span class="term"><em class="parameter"><code>proj</code></em></span></dt><dd><p>
   8                     Specifies the projection matrix (as from a <a class="citerefentry" href="glGetDoublev.xml"><span class="citerefentry"><span class="refentrytitle">glGetDoublev</span></span></a> call).
   9                 </p></dd><dt><span class="term"><em class="parameter"><code>view</code></em></span></dt><dd><p>
  10                     Specifies the viewport (as from a <a class="citerefentry" href="glGetIntegerv.xml"><span class="citerefentry"><span class="refentrytitle">glGetIntegerv</span></span></a> call).
  11                 </p></dd><dt><span class="term"><em class="parameter"><code>objX</code></em>, </span><span class="term"><em class="parameter"><code>objY</code></em>, </span><span class="term"><em class="parameter"><code>objZ</code></em></span></dt><dd><p>
  12                     Returns the computed object coordinates.
  13                 </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
  14             <code class="function">gluUnProject</code> maps the specified window coordinates into object
  15             coordinates using <em class="parameter"><code>model</code></em>, <em class="parameter"><code>proj</code></em>, and <em class="parameter"><code>view</code></em>.
  16             The result is stored in <em class="parameter"><code>objX</code></em>, <em class="parameter"><code>objY</code></em>, and <em class="parameter"><code>objZ</code></em>. A return value of
  17             <code class="constant">GLU_TRUE</code> indicates success; a return value of <code class="constant">GLU_FALSE</code>
  18             indicates failure.
  19         </p><p>
  20             To compute the coordinates
  21             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  22
  23                 <mml:mfenced open="(" close=")">
  24                     <mml:mi mathvariant="italic">objX</mml:mi>
  25                     <mml:mi mathvariant="italic">objY</mml:mi>
  26                     <mml:mi mathvariant="italic">objZ</mml:mi>
  27                 </mml:mfenced>
  28             </mml:math>,
  29             <code class="function">gluUnProject</code> multiplies the normalized device coordinates by the inverse of
  30             <em class="parameter"><code>model</code></em> * <em class="parameter"><code>proj</code></em> as follows:
  31         </p><p>
  32             </p><div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  33
  34                 <mml:mrow>
  35                     <mml:mfenced open="(" close=")">
  36                         <mml:mtable>
  37                             <mml:mtr><mml:mtd>
  38                                 <mml:mi mathvariant="italic">objX</mml:mi>
  39                             </mml:mtd></mml:mtr>
  40                             <mml:mtr><mml:mtd>
  41                                 <mml:mi mathvariant="italic">objY</mml:mi>
  42                             </mml:mtd></mml:mtr>
  43                             <mml:mtr><mml:mtd>
  44                                 <mml:mi mathvariant="italic">objZ</mml:mi>
  45                             </mml:mtd></mml:mtr>
  46                             <mml:mtr><mml:mtd>
  47                                 <mml:mi mathvariant="italic">W</mml:mi>
  48                             </mml:mtd></mml:mtr>
  49                         </mml:mtable>
  50                     </mml:mfenced>
  51                     <mml:mo>=</mml:mo>
  52                     <mml:mrow>
  53                         <mml:mrow>
  54                             <mml:mi mathvariant="italic">INV</mml:mi>
  55                             <mml:mo>⁡</mml:mo>
  56                             <mml:mfenced open="(" close=")">
  57                                 <mml:mrow>
  58                                     <mml:mi mathvariant="italic">P</mml:mi>
  59                                     <mml:mo>⁢</mml:mo>
  60                                     <mml:mi mathvariant="italic">M</mml:mi>
  61                                 </mml:mrow>
  62                             </mml:mfenced>
  63                         </mml:mrow>
  64                         <mml:mo>⁢</mml:mo>
  65                         <mml:mfenced open="(" close=")">
  66                             <mml:mtable>
  67                                 <mml:mtr><mml:mtd>
  68                                     <mml:mrow>
  69                                         <mml:mfrac>
  70                                             <mml:mfenced open="" close="">
  71                                                 <mml:mrow>
  72                                                     <mml:mn>2</mml:mn>
  73                                                     <mml:mo>⁡</mml:mo>
  74                                                     <mml:mfenced open="(" close=")">
  75                                                         <mml:mrow>
  76                                                             <mml:mi mathvariant="italic">winX</mml:mi>
  77                                                             <mml:mo>-</mml:mo>
  78                                                             <mml:mrow>
  79                                                                 <mml:mi mathvariant="italic">view</mml:mi>
  80                                                                 <mml:mo>⁡</mml:mo>
  81                                                                 <mml:mfenced open="[" close="]">
  82                                                                     <mml:mn>0</mml:mn>
  83                                                                 </mml:mfenced>
  84                                                             </mml:mrow>
  85                                                         </mml:mrow>
  86                                                     </mml:mfenced>
  87                                                 </mml:mrow>
  88                                             </mml:mfenced>
  89                                             <mml:mfenced open="" close="">
  90                                                 <mml:mrow>
  91                                                     <mml:mi mathvariant="italic">view</mml:mi>
  92                                                     <mml:mo>⁡</mml:mo>
  93                                                     <mml:mfenced open="[" close="]">
  94                                                         <mml:mn>2</mml:mn>
  95                                                     </mml:mfenced>
  96                                                 </mml:mrow>
  97                                             </mml:mfenced>
  98                                         </mml:mfrac>
  99                                         <mml:mo>-</mml:mo>
 100                                         <mml:mn>1</mml:mn>
 101                                     </mml:mrow>
 102                                 </mml:mtd></mml:mtr>
 103                                 <mml:mtr><mml:mtd>
 104                                     <mml:mrow>
 105                                         <mml:mfrac>
 106                                             <mml:mfenced open="" close="">
 107                                                 <mml:mrow>
 108                                                     <mml:mn>2</mml:mn>
 109                                                     <mml:mo>⁡</mml:mo>
 110                                                     <mml:mfenced open="(" close=")">
 111                                                         <mml:mrow>
 112                                                             <mml:mi mathvariant="italic">winY</mml:mi>
 113                                                             <mml:mo>-</mml:mo>
 114                                                             <mml:mrow>
 115                                                                 <mml:mi mathvariant="italic">view</mml:mi>
 116                                                                 <mml:mo>⁡</mml:mo>
 117                                                                 <mml:mfenced open="[" close="]">
 118                                                                     <mml:mn>1</mml:mn>
 119                                                                 </mml:mfenced>
 120                                                             </mml:mrow>
 121                                                         </mml:mrow>
 122                                                     </mml:mfenced>
 123                                                 </mml:mrow>
 124                                             </mml:mfenced>
 125                                             <mml:mfenced open="" close="">
 126                                                 <mml:mrow>
 127                                                     <mml:mi mathvariant="italic">view</mml:mi>
 128                                                     <mml:mo>⁡</mml:mo>
 129                                                     <mml:mfenced open="[" close="]">
 130                                                         <mml:mn>3</mml:mn>
 131                                                     </mml:mfenced>
 132                                                 </mml:mrow>
 133                                             </mml:mfenced>
 134                                         </mml:mfrac>
 135                                         <mml:mo>-</mml:mo>
 136                                         <mml:mn>1</mml:mn>
 137                                     </mml:mrow>
 138                                 </mml:mtd></mml:mtr>
 139                                 <mml:mtr><mml:mtd>
 140                                     <mml:mrow>
 141                                         <mml:mrow>
 142                                             <mml:mn>2</mml:mn>
 143                                             <mml:mo>⁡</mml:mo>
 144                                             <mml:mfenced open="(" close=")">
 145                                                 <mml:mi mathvariant="italic">winZ</mml:mi>
 146                                             </mml:mfenced>
 147                                         </mml:mrow>
 148                                         <mml:mo>-</mml:mo>
 149                                         <mml:mn>1</mml:mn>
 150                                     </mml:mrow>
 151                                 </mml:mtd></mml:mtr>
 152                                 <mml:mtr><mml:mtd>
 153                                     <mml:mn>1</mml:mn>
 154                                 </mml:mtd></mml:mtr>
 155                             </mml:mtable>
 156                         </mml:mfenced>
 157                     </mml:mrow>
 158                 </mml:mrow>
 159             </mml:math></div><p>
 160             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">INV</mml:mi></mml:math>
 161             denotes matrix inversion.
 162             W is an unused variable, included for consistent matrix notation.
 163         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
 164             <a class="citerefentry" href="gluProject.xml"><span class="citerefentry"><span class="refentrytitle">gluProject</span></span></a>,
 165             <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a>
 166         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
 167             Copyright <span class="trademark"></span>© 1991-2006
 168             Silicon Graphics, Inc. This document is licensed under the SGI
 169             Free Software B License. For details, see
 170             <a class="ulink" href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
 171         </p></div></div></body></html>