upstream-man-pages/man2/xhtml/glScale.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>glScale</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glScale"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glScale — multiply the current matrix by a general scaling matrix</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">glScaled</b>(</code></td><td>GLdouble  </td><td><var class="pdparam">x</var>, </td></tr><tr><td> </td><td>GLdouble  </td><td><var class="pdparam">y</var>, </td></tr><tr><td> </td><td>GLdouble  </td><td><var class="pdparam">z</var><code>)</code>;</td></tr></table></div><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">glScalef</b>(</code></td><td>GLfloat  </td><td><var class="pdparam">x</var>, </td></tr><tr><td> </td><td>GLfloat  </td><td><var class="pdparam">y</var>, </td></tr><tr><td> </td><td>GLfloat  </td><td><var class="pdparam">z</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>x</code></em>, </span><span class="term"><em class="parameter"><code>y</code></em>, </span><span class="term"><em class="parameter"><code>z</code></em></span></dt><dd><p>
   4                     Specify scale factors along the <span class="emphasis"><em>x</em></span>, <span class="emphasis"><em>y</em></span>, and <span class="emphasis"><em>z</em></span> axes, respectively.
   5                 </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
   6             <code class="function">glScale</code> produces a nonuniform scaling along the <span class="emphasis"><em>x</em></span>, <span class="emphasis"><em>y</em></span>, and
   7             <span class="emphasis"><em>z</em></span> axes.
   8             The three parameters indicate the desired scale factor along
   9             each of the three axes.
  10         </p><p>
  11             The current matrix
  12             (see <a class="citerefentry" href="glMatrixMode.xml"><span class="citerefentry"><span class="refentrytitle">glMatrixMode</span></span></a>)
  13             is multiplied by this scale matrix,
  14             and the product replaces the current matrix
  15             as if <a class="citerefentry" href="glMultMatrix.xml"><span class="citerefentry"><span class="refentrytitle">glMultMatrix</span></span></a> were called with the following matrix
  16             as its argument:
  17         </p><p>
  18             </p><div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  19
  20                 <mml:mfenced open="(" close=")">
  21                     <mml:mtable>
  22                         <mml:mtr>
  23                             <mml:mtd>
  24                                 <mml:mi mathvariant="italic">x</mml:mi>
  25                             </mml:mtd>
  26                             <mml:mtd>
  27                                 <mml:mn>0</mml:mn>
  28                             </mml:mtd>
  29                             <mml:mtd>
  30                                 <mml:mn>0</mml:mn>
  31                             </mml:mtd>
  32                             <mml:mtd>
  33                                 <mml:mn>0</mml:mn>
  34                             </mml:mtd>
  35                         </mml:mtr>
  36                         <mml:mtr>
  37                             <mml:mtd>
  38                                 <mml:mn>0</mml:mn>
  39                             </mml:mtd>
  40                             <mml:mtd>
  41                                 <mml:mi mathvariant="italic">y</mml:mi>
  42                             </mml:mtd>
  43                             <mml:mtd>
  44                                 <mml:mn>0</mml:mn>
  45                             </mml:mtd>
  46                             <mml:mtd>
  47                                 <mml:mn>0</mml:mn>
  48                             </mml:mtd>
  49                         </mml:mtr>
  50                         <mml:mtr>
  51                             <mml:mtd>
  52                                 <mml:mn>0</mml:mn>
  53                             </mml:mtd>
  54                             <mml:mtd>
  55                                 <mml:mn>0</mml:mn>
  56                             </mml:mtd>
  57                             <mml:mtd>
  58                                 <mml:mi mathvariant="italic">z</mml:mi>
  59                             </mml:mtd>
  60                             <mml:mtd>
  61                                 <mml:mn>0</mml:mn>
  62                             </mml:mtd>
  63                         </mml:mtr>
  64                         <mml:mtr>
  65                             <mml:mtd>
  66                                 <mml:mn>0</mml:mn>
  67                             </mml:mtd>
  68                             <mml:mtd>
  69                                 <mml:mn>0</mml:mn>
  70                             </mml:mtd>
  71                             <mml:mtd>
  72                                 <mml:mn>0</mml:mn>
  73                             </mml:mtd>
  74                             <mml:mtd>
  75                                 <mml:mn>1</mml:mn>
  76                             </mml:mtd>
  77                         </mml:mtr>
  78                     </mml:mtable>
  79                 </mml:mfenced>
  80             </mml:math></div><p>
  81         </p><p>
  82             If the matrix mode is either <code class="constant">GL_MODELVIEW</code> or <code class="constant">GL_PROJECTION</code>,
  83             all objects drawn after <code class="function">glScale</code> is called are scaled.
  84         </p><p>
  85             Use <a class="citerefentry" href="glPushMatrix.xml"><span class="citerefentry"><span class="refentrytitle">glPushMatrix</span></span></a> and <a class="citerefentry" href="glPopMatrix.xml"><span class="citerefentry"><span class="refentrytitle">glPopMatrix</span></span></a> to save and restore
  86             the unscaled coordinate
  87             system.
  88         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
  89             If scale factors other than 1 are applied to the modelview matrix
  90             and lighting is enabled, lighting often appears wrong.
  91             In that case, enable automatic normalization of normals by
  92             calling <a class="citerefentry" href="glEnable.xml"><span class="citerefentry"><span class="refentrytitle">glEnable</span></span></a> with the argument <code class="constant">GL_NORMALIZE</code>.
  93         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>
  94             <code class="constant">GL_INVALID_OPERATION</code> is generated if <code class="function">glScale</code>
  95             is executed between the execution of
  96             <a class="citerefentry" href="glBegin.xml"><span class="citerefentry"><span class="refentrytitle">glBegin</span></span></a>
  97             and the corresponding execution of <a class="citerefentry" href="glEnd.xml"><span class="citerefentry"><span class="refentrytitle">glEnd</span></span></a>.
  98         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p>
  99             <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_MATRIX_MODE</code>
 100         </p><p>
 101             <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_COLOR_MATRIX</code>
 102         </p><p>
 103             <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_MODELVIEW_MATRIX</code>
 104         </p><p>
 105             <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_PROJECTION_MATRIX</code>
 106         </p><p>
 107             <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_TEXTURE_MATRIX</code>
 108         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
 109             <a class="citerefentry" href="glMatrixMode.xml"><span class="citerefentry"><span class="refentrytitle">glMatrixMode</span></span></a>,
 110             <a class="citerefentry" href="glMultMatrix.xml"><span class="citerefentry"><span class="refentrytitle">glMultMatrix</span></span></a>,
 111             <a class="citerefentry" href="glPushMatrix.xml"><span class="citerefentry"><span class="refentrytitle">glPushMatrix</span></span></a>,
 112             <a class="citerefentry" href="glRotate.xml"><span class="citerefentry"><span class="refentrytitle">glRotate</span></span></a>,
 113             <a class="citerefentry" href="glTranslate.xml"><span class="citerefentry"><span class="refentrytitle">glTranslate</span></span></a>
 114         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
 115             Copyright <span class="trademark"></span>© 1991-2006
 116             Silicon Graphics, Inc. This document is licensed under the SGI
 117             Free Software B License. For details, see
 118             <a class="ulink" href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
 119         </p></div></div></body></html>