upstream-man-pages/man2/xhtml/glGetTexParameter.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>glGetTexParameter</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glGetTexParameter"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glGetTexParameter — return texture parameter values</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">glGetTexParameterfv</b>(</code></td><td>GLenum  </td><td><var class="pdparam">target</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">glGetTexParameteriv</b>(</code></td><td>GLenum  </td><td><var class="pdparam">target</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>target</code></em></span></dt><dd><p>
   4                     Specifies the symbolic name of the target texture.
   5                     <code class="constant">GL_TEXTURE_1D</code>,
   6                     <code class="constant">GL_TEXTURE_2D</code>,
   7                     <code class="constant">GL_TEXTURE_3D</code>, and
   8                     <code class="constant">GL_TEXTURE_CUBE_MAP</code>
   9                     are accepted.
  10                 </p></dd><dt><span class="term"><em class="parameter"><code>pname</code></em></span></dt><dd><p>
  11                     Specifies the symbolic name of a texture parameter.
  12                     <code class="constant">GL_TEXTURE_MAG_FILTER</code>,
  13                     <code class="constant">GL_TEXTURE_MIN_FILTER</code>,
  14                     <code class="constant">GL_TEXTURE_MIN_LOD</code>,
  15                     <code class="constant">GL_TEXTURE_MAX_LOD</code>,
  16                     <code class="constant">GL_TEXTURE_BASE_LEVEL</code>,
  17                     <code class="constant">GL_TEXTURE_MAX_LEVEL</code>,
  18                     <code class="constant">GL_TEXTURE_WRAP_S</code>,
  19                     <code class="constant">GL_TEXTURE_WRAP_T</code>,
  20                     <code class="constant">GL_TEXTURE_WRAP_R</code>,
  21                     <code class="constant">GL_TEXTURE_BORDER_COLOR</code>,
  22                     <code class="constant">GL_TEXTURE_PRIORITY</code>,
  23                     <code class="constant">GL_TEXTURE_RESIDENT</code>,
  24                     <code class="constant">GL_TEXTURE_COMPARE_MODE</code>,
  25                     <code class="constant">GL_TEXTURE_COMPARE_FUNC</code>,
  26                     <code class="constant">GL_DEPTH_TEXTURE_MODE</code>, and
  27                     <code class="constant">GL_GENERATE_MIPMAP</code>
  28                     are accepted.
  29                 </p></dd><dt><span class="term"><em class="parameter"><code>params</code></em></span></dt><dd><p>
  30                     Returns the texture parameters.
  31                 </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
  32             <code class="function">glGetTexParameter</code> returns in <em class="parameter"><code>params</code></em> the value or values of the texture parameter
  33             specified as <em class="parameter"><code>pname</code></em>.
  34             <em class="parameter"><code>target</code></em> defines the target texture,
  35             either <code class="constant">GL_TEXTURE_1D</code>, <code class="constant">GL_TEXTURE_2D</code>, <code class="constant">GL_TEXTURE_3D</code>, or <code class="constant">GL_TEXTURE_CUBE_MAP</code>,
  36             to specify one-, two-, or three-dimensional or cube-mapped texturing.
  37             <em class="parameter"><code>pname</code></em> accepts the same symbols as <a class="citerefentry" href="glTexParameter.xml"><span class="citerefentry"><span class="refentrytitle">glTexParameter</span></span></a>,
  38             with the same interpretations:
  39         </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_TEXTURE_MAG_FILTER</code></span></dt><dd><p>
  40                         Returns the single-valued texture magnification filter,
  41                         a symbolic constant. The initial value is <code class="constant">GL_LINEAR</code>.
  42                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_MIN_FILTER</code></span></dt><dd><p>
  43                         Returns the single-valued texture minification filter,
  44                         a symbolic constant. The initial value is <code class="constant">GL_NEAREST_MIPMAP_LINEAR</code>.
  45                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_MIN_LOD</code></span></dt><dd><p>
  46                         Returns the single-valued texture minimum level-of-detail value.  The
  47                         initial value is
  48                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  49
  50                             <mml:mn>-1000</mml:mn>
  51                         </mml:math>.
  52                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_MAX_LOD</code></span></dt><dd><p>
  53                         Returns the single-valued texture maximum level-of-detail value. The
  54                         initial value is 1000.
  55                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_BASE_LEVEL</code></span></dt><dd><p>
  56                         Returns the single-valued base texture mipmap level.  The initial value is 0.
  57                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_MAX_LEVEL</code></span></dt><dd><p>
  58                         Returns the single-valued maximum texture mipmap array level.  The initial
  59                         value is 1000.
  60                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_WRAP_S</code></span></dt><dd><p>
  61                         Returns the single-valued wrapping function for texture coordinate
  62                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>,
  63                         a symbolic constant. The initial value is <code class="constant">GL_REPEAT</code>.
  64                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_WRAP_T</code></span></dt><dd><p>
  65                         Returns the single-valued wrapping function for texture coordinate
  66                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">t</mml:mi></mml:math>,
  67                         a symbolic constant. The initial value is <code class="constant">GL_REPEAT</code>.
  68                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_WRAP_R</code></span></dt><dd><p>
  69                         Returns the single-valued wrapping function for texture coordinate
  70                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">r</mml:mi></mml:math>,
  71                         a symbolic constant. The initial value is <code class="constant">GL_REPEAT</code>.
  72                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_BORDER_COLOR</code></span></dt><dd><p>
  73                         Returns four integer or floating-point numbers that comprise the RGBA color
  74                         of the texture border.
  75                         Floating-point values are returned in the range
  76                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  77
  78                             <mml:mfenced open="[" close="]">
  79                                 <mml:mn>0</mml:mn>
  80                                 <mml:mn>1</mml:mn>
  81                             </mml:mfenced>
  82                         </mml:math>.
  83                         Integer values are returned as a linear mapping of the internal floating-point
  84                         representation such that 1.0 maps to the most positive representable
  85                         integer and
  86                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  87
  88                             <mml:mn>-1.0</mml:mn>
  89                         </mml:math>
  90                         maps to the most negative representable
  91                         integer. The initial value is (0, 0, 0, 0).
  92                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_PRIORITY</code></span></dt><dd><p>
  93                         Returns the residence priority of the target texture (or the named
  94                         texture bound to it). The initial value is 1.
  95                         See <a class="citerefentry" href="glPrioritizeTextures.xml"><span class="citerefentry"><span class="refentrytitle">glPrioritizeTextures</span></span></a>.
  96                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_RESIDENT</code></span></dt><dd><p>
  97                         Returns the residence status of the target texture.
  98                         If the value returned in <em class="parameter"><code>params</code></em> is <code class="constant">GL_TRUE</code>, the texture is
  99                         resident in texture memory.
 100                         See <a class="citerefentry" href="glAreTexturesResident.xml"><span class="citerefentry"><span class="refentrytitle">glAreTexturesResident</span></span></a>.
 101                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_COMPARE_MODE</code></span></dt><dd><p>
 102                         Returns a single-valued texture comparison mode, a symbolic constant.  The
 103                         initial value is <code class="constant">GL_NONE</code>. See <a class="citerefentry" href="glTexParameter.xml"><span class="citerefentry"><span class="refentrytitle">glTexParameter</span></span></a>.
 104                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_COMPARE_FUNC</code></span></dt><dd><p>
 105                         Returns a single-valued texture comparison function, a symbolic constant.  The
 106                         initial value is <code class="constant">GL_LEQUAL</code>. See <a class="citerefentry" href="glTexParameter.xml"><span class="citerefentry"><span class="refentrytitle">glTexParameter</span></span></a>.
 107                     </p></dd><dt><span class="term"><code class="constant">GL_DEPTH_TEXTURE_MODE</code></span></dt><dd><p>
 108                         Returns a single-valued texture format indicating how the depth values
 109                         should be converted into color components.  The initial value is
 110                         <code class="constant">GL_LUMINANCE</code>.  See <a class="citerefentry" href="glTexParameter.xml"><span class="citerefentry"><span class="refentrytitle">glTexParameter</span></span></a>.
 111                     </p></dd><dt><span class="term"><code class="constant">GL_GENERATE_MIPMAP</code></span></dt><dd><p>
 112                         Returns a single boolean value indicating if automatic mipmap level updates
 113                         are enabled.
 114                         See <a class="citerefentry" href="glTexParameter.xml"><span class="citerefentry"><span class="refentrytitle">glTexParameter</span></span></a>.
 115                     </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
 116             <code class="constant">GL_TEXTURE_PRIORITY</code> and <code class="constant">GL_TEXTURE_RESIDENT</code> are
 117             available only if the GL version is 1.1 or greater.
 118         </p><p>
 119             <code class="constant">GL_TEXTURE_3D</code>,
 120             <code class="constant">GL_TEXTURE_MIN_LOD</code>, <code class="constant">GL_TEXTURE_MAX_LOD</code>, <code class="constant">GL_TEXTURE_BASE_LEVEL</code>,
 121             <code class="constant">GL_TEXTURE_MAX_LEVEL</code>, and <code class="constant">GL_TEXTURE_WRAP_R</code> are available only
 122             if the GL version is 1.2 or greater.
 123         </p><p>
 124             <code class="constant">GL_TEXTURE_COMPARE_MODE</code>, <code class="constant">GL_TEXTURE_COMPARE_FUNC</code>, and
 125             <code class="constant">GL_GENERATE_MIPMAP</code> is available only if the GL version is 1.4 or
 126             greater.
 127         </p><p>
 128             If an error is generated,
 129             no change is made to the contents of <em class="parameter"><code>params</code></em>.
 130         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>
 131             <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>target</code></em> or <em class="parameter"><code>pname</code></em> is not an
 132             accepted value.
 133         </p><p>
 134             <code class="constant">GL_INVALID_OPERATION</code> is generated if <code class="function">glGetTexParameter</code>
 135             is executed between the execution of <a class="citerefentry" href="glBegin.xml"><span class="citerefentry"><span class="refentrytitle">glBegin</span></span></a>
 136             and the corresponding execution of <a class="citerefentry" href="glEnd.xml"><span class="citerefentry"><span class="refentrytitle">glEnd</span></span></a>.
 137         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
 138             <a class="citerefentry" href="glAreTexturesResident.xml"><span class="citerefentry"><span class="refentrytitle">glAreTexturesResident</span></span></a>,
 139             <a class="citerefentry" href="glPrioritizeTextures.xml"><span class="citerefentry"><span class="refentrytitle">glPrioritizeTextures</span></span></a>,
 140             <a class="citerefentry" href="glTexParameter.xml"><span class="citerefentry"><span class="refentrytitle">glTexParameter</span></span></a>
 141         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
 142             Copyright <span class="trademark"></span>© 1991-2006
 143             Silicon Graphics, Inc. This document is licensed under the SGI
 144             Free Software B License. For details, see
 145             <a class="ulink" href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
 146         </p></div></div></body></html>