upstream-man-pages/man2/xhtml/glGetTexGen.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>glGetTexGen</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glGetTexGen"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glGetTexGen — return texture coordinate generation parameters</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">glGetTexGendv</b>(</code></td><td>GLenum  </td><td><var class="pdparam">coord</var>, </td></tr><tr><td> </td><td>GLenum  </td><td><var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>GLdouble *  </td><td><var class="pdparam">params</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">glGetTexGenfv</b>(</code></td><td>GLenum  </td><td><var class="pdparam">coord</var>, </td></tr><tr><td> </td><td>GLenum  </td><td><var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>GLfloat *  </td><td><var class="pdparam">params</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">glGetTexGeniv</b>(</code></td><td>GLenum  </td><td><var class="pdparam">coord</var>, </td></tr><tr><td> </td><td>GLenum  </td><td><var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>GLint *  </td><td><var class="pdparam">params</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>coord</code></em></span></dt><dd><p>
   4                     Specifies a texture coordinate.
   5                     Must be
   6                     <code class="constant">GL_S</code>,
   7                     <code class="constant">GL_T</code>,
   8                     <code class="constant">GL_R</code>, or
   9                     <code class="constant">GL_Q</code>.
  10                 </p></dd><dt><span class="term"><em class="parameter"><code>pname</code></em></span></dt><dd><p>
  11                     Specifies the symbolic name of the value(s) to be returned.
  12                     Must be either <code class="constant">GL_TEXTURE_GEN_MODE</code>
  13                     or the name of one of the texture generation plane equations:
  14                     <code class="constant">GL_OBJECT_PLANE</code> or <code class="constant">GL_EYE_PLANE</code>.
  15                 </p></dd><dt><span class="term"><em class="parameter"><code>params</code></em></span></dt><dd><p>
  16                     Returns the requested data.
  17                 </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
  18             <code class="function">glGetTexGen</code> returns in <em class="parameter"><code>params</code></em> selected parameters of a texture coordinate
  19             generation function that was specified using <a class="citerefentry" href="glTexGen.xml"><span class="citerefentry"><span class="refentrytitle">glTexGen</span></span></a>.
  20             <em class="parameter"><code>coord</code></em> names one of the (<span class="emphasis"><em>s</em></span>, <span class="emphasis"><em>t</em></span>, <span class="emphasis"><em>r</em></span>, <span class="emphasis"><em>q</em></span>)
  21             texture coordinates,
  22             using the symbolic constant
  23             <code class="constant">GL_S</code>,
  24             <code class="constant">GL_T</code>,
  25             <code class="constant">GL_R</code>, or
  26             <code class="constant">GL_Q</code>.
  27         </p><p>
  28             <em class="parameter"><code>pname</code></em> specifies one of three symbolic names:
  29         </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_TEXTURE_GEN_MODE</code></span></dt><dd><p>
  30                         <em class="parameter"><code>params</code></em> returns the single-valued texture generation function,
  31                         a symbolic constant. The initial value is <code class="constant">GL_EYE_LINEAR</code>.
  32                     </p></dd><dt><span class="term"><code class="constant">GL_OBJECT_PLANE</code></span></dt><dd><p>
  33                         <em class="parameter"><code>params</code></em> returns the four plane equation coefficients that specify
  34                         object linear-coordinate generation.
  35                         Integer values, when requested,
  36                         are mapped directly from the internal floating-point representation.
  37                     </p></dd><dt><span class="term"><code class="constant">GL_EYE_PLANE</code></span></dt><dd><p>
  38                         <em class="parameter"><code>params</code></em> returns the four plane equation coefficients that specify
  39                         eye linear-coordinate generation.
  40                         Integer values,
  41                         when requested,
  42                         are mapped directly from the internal floating-point representation.
  43                         The returned values are those maintained in eye coordinates.
  44                         They are not equal to the values specified using <a class="citerefentry" href="glTexGen.xml"><span class="citerefentry"><span class="refentrytitle">glTexGen</span></span></a>,
  45                         unless the modelview matrix was identity when <a class="citerefentry" href="glTexGen.xml"><span class="citerefentry"><span class="refentrytitle">glTexGen</span></span></a> was called.
  46                     </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
  47             If an error is generated,
  48             no change is made to the contents of <em class="parameter"><code>params</code></em>.
  49         </p><p>
  50             For OpenGL versions 1.3 and greater, or when the <code class="code">ARB_multitexture</code> extension is supported, <code class="function">glGetTexGen</code> returns
  51             the texture coordinate generation parameters for the active texture unit.
  52         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>
  53             <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>coord</code></em> or <em class="parameter"><code>pname</code></em> is not an
  54             accepted value.
  55         </p><p>
  56             <code class="constant">GL_INVALID_OPERATION</code> is generated if <code class="function">glGetTexGen</code>
  57             is executed between the execution of <a class="citerefentry" href="glBegin.xml"><span class="citerefentry"><span class="refentrytitle">glBegin</span></span></a>
  58             and the corresponding execution of <a class="citerefentry" href="glEnd.xml"><span class="citerefentry"><span class="refentrytitle">glEnd</span></span></a>.
  59         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
  60             <a class="citerefentry" href="glActiveTexture.xml"><span class="citerefentry"><span class="refentrytitle">glActiveTexture</span></span></a>,
  61             <a class="citerefentry" href="glTexGen.xml"><span class="citerefentry"><span class="refentrytitle">glTexGen</span></span></a>
  62         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
  63             Copyright <span class="trademark"></span>© 1991-2006
  64             Silicon Graphics, Inc. This document is licensed under the SGI
  65             Free Software B License. For details, see
  66             <a class="ulink" href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
  67         </p></div></div></body></html>