upstream-doc/man3/xhtml/glGetTexParameter.xml

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   4 <?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" /><link rel="stylesheet" type="text/css" href="opengl-man.css" /><title>glGetTexParameter - OpenGL 3.3 Reference Pages</title><meta name="generator" content="DocBook XSL Stylesheets V1.69.1" /></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 class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">glGetTexParameterIiv</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 class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">glGetTexParameterIuiv</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>GLuint *  </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>
   5                     Specifies the symbolic name of the target texture.
   6                     <code class="constant">GL_TEXTURE_1D</code>,
   7                     <code class="constant">GL_TEXTURE_2D</code>,
   8                     <code class="constant">GL_TEXTURE_1D_ARRAY</code>,
   9                     <code class="constant">GL_TEXTURE_2D_ARRAY</code>,
  10                     <code class="constant">GL_TEXTURE_3D</code>,
  11                     <code class="constant">GL_TEXTURE_RECTANGLE</code>, and
  12                     <code class="constant">GL_TEXTURE_CUBE_MAP</code>
  13                     are accepted.
  14                 </p></dd><dt><span class="term"><em class="parameter"><code>pname</code></em></span></dt><dd><p>
  15                     Specifies the symbolic name of a texture parameter.
  16                     <code class="constant">GL_TEXTURE_BASE_LEVEL</code>,
  17                     <code class="constant">GL_TEXTURE_BORDER_COLOR</code>,
  18                     <code class="constant">GL_TEXTURE_COMPARE_MODE</code>,
  19                     <code class="constant">GL_TEXTURE_COMPARE_FUNC</code>,
  20                     <code class="constant">GL_TEXTURE_LOD_BIAS</code>,
  21                     <code class="constant">GL_TEXTURE_MAG_FILTER</code>,
  22                     <code class="constant">GL_TEXTURE_MAX_LEVEL</code>,
  23                     <code class="constant">GL_TEXTURE_MAX_LOD</code>,
  24                     <code class="constant">GL_TEXTURE_MIN_FILTER</code>,
  25                     <code class="constant">GL_TEXTURE_MIN_LOD</code>,
  26                     <code class="constant">GL_TEXTURE_SWIZZLE_R</code>,
  27                     <code class="constant">GL_TEXTURE_SWIZZLE_G</code>,
  28                     <code class="constant">GL_TEXTURE_SWIZZLE_B</code>,
  29                     <code class="constant">GL_TEXTURE_SWIZZLE_A</code>,
  30                     <code class="constant">GL_TEXTURE_SWIZZLE_RGBA</code>,
  31                     <code class="constant">GL_TEXTURE_WRAP_S</code>,
  32                     <code class="constant">GL_TEXTURE_WRAP_T</code>, and
  33                     <code class="constant">GL_TEXTURE_WRAP_R</code>
  34                     are accepted.
  35                 </p></dd><dt><span class="term"><em class="parameter"><code>params</code></em></span></dt><dd><p>
  36                     Returns the texture parameters.
  37                 </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
  38             <code class="function">glGetTexParameter</code> returns in <em class="parameter"><code>params</code></em> the value or values of the texture parameter
  39             specified as <em class="parameter"><code>pname</code></em>.
  40             <em class="parameter"><code>target</code></em> defines the target texture.
  41             <code class="constant">GL_TEXTURE_1D</code>,
  42             <code class="constant">GL_TEXTURE_2D</code>,
  43             <code class="constant">GL_TEXTURE_3D</code>,
  44             <code class="constant">GL_TEXTURE_1D_ARRAY</code>,
  45             <code class="constant">GL_TEXTURE_2D_ARRAY</code>,
  46             <code class="constant">GL_TEXTURE_RECTANGLE</code>, and
  47             <code class="constant">GL_TEXTURE_CUBE_MAP</code>
  48             specify one-, two-, or three-dimensional, one-dimensional array, two-dimensional array, rectangle or cube-mapped texturing, respectively.
  49             <em class="parameter"><code>pname</code></em> accepts the same symbols as <a href="glTexParameter.xml"><span class="citerefentry"><span class="refentrytitle">glTexParameter</span></span></a>,
  50             with the same interpretations:
  51         </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_TEXTURE_MAG_FILTER</code></span></dt><dd><p>
  52                         Returns the single-valued texture magnification filter,
  53                         a symbolic constant. The initial value is <code class="constant">GL_LINEAR</code>.
  54                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_MIN_FILTER</code></span></dt><dd><p>
  55                         Returns the single-valued texture minification filter,
  56                         a symbolic constant. The initial value is <code class="constant">GL_NEAREST_MIPMAP_LINEAR</code>.
  57                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_MIN_LOD</code></span></dt><dd><p>
  58                         Returns the single-valued texture minimum level-of-detail value.  The
  59                         initial value is
  60                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  61
  62                             <mml:mn>-1000</mml:mn>
  63                         </mml:math>.
  64                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_MAX_LOD</code></span></dt><dd><p>
  65                         Returns the single-valued texture maximum level-of-detail value. The
  66                         initial value is 1000.
  67                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_BASE_LEVEL</code></span></dt><dd><p>
  68                         Returns the single-valued base texture mipmap level.  The initial value is 0.
  69                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_MAX_LEVEL</code></span></dt><dd><p>
  70                         Returns the single-valued maximum texture mipmap array level.  The initial
  71                         value is 1000.
  72                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_SWIZZLE_R</code></span></dt><dd><p>
  73                         Returns the red component swizzle. The initial value is <code class="constant">GL_RED</code>.
  74                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_SWIZZLE_G</code></span></dt><dd><p>
  75                         Returns the green component swizzle. The initial value is <code class="constant">GL_GREEN</code>.
  76                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_SWIZZLE_B</code></span></dt><dd><p>
  77                         Returns the blue component swizzle. The initial value is <code class="constant">GL_BLUE</code>.
  78                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_SWIZZLE_A</code></span></dt><dd><p>
  79                         Returns the alpha component swizzle. The initial value is <code class="constant">GL_ALPHA</code>.
  80                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_SWIZZLE_RGBA</code></span></dt><dd><p>
  81                         Returns the component swizzle for all channels in a single query.
  82                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_WRAP_S</code></span></dt><dd><p>
  83                         Returns the single-valued wrapping function for texture coordinate
  84                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>,
  85                         a symbolic constant. The initial value is <code class="constant">GL_REPEAT</code>.
  86                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_WRAP_T</code></span></dt><dd><p>
  87                         Returns the single-valued wrapping function for texture coordinate
  88                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">t</mml:mi></mml:math>,
  89                         a symbolic constant. The initial value is <code class="constant">GL_REPEAT</code>.
  90                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_WRAP_R</code></span></dt><dd><p>
  91                         Returns the single-valued wrapping function for texture coordinate
  92                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">r</mml:mi></mml:math>,
  93                         a symbolic constant. The initial value is <code class="constant">GL_REPEAT</code>.
  94                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_BORDER_COLOR</code></span></dt><dd><p>
  95                         Returns four integer or floating-point numbers that comprise the RGBA color
  96                         of the texture border.
  97                         Floating-point values are returned in the range
  98                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  99
 100                             <mml:mfenced open="[" close="]">
 101                                 <mml:mn>0</mml:mn>
 102                                 <mml:mn>1</mml:mn>
 103                             </mml:mfenced>
 104                         </mml:math>.
 105                         Integer values are returned as a linear mapping of the internal floating-point
 106                         representation such that 1.0 maps to the most positive representable
 107                         integer and
 108                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 109
 110                             <mml:mn>-1.0</mml:mn>
 111                         </mml:math>
 112                         maps to the most negative representable
 113                         integer. The initial value is (0, 0, 0, 0).
 114                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_COMPARE_MODE</code></span></dt><dd><p>
 115                         Returns a single-valued texture comparison mode, a symbolic constant.  The
 116                         initial value is <code class="constant">GL_NONE</code>. See <a href="glTexParameter.xml"><span class="citerefentry"><span class="refentrytitle">glTexParameter</span></span></a>.
 117                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_COMPARE_FUNC</code></span></dt><dd><p>
 118                         Returns a single-valued texture comparison function, a symbolic constant.  The
 119                         initial value is <code class="constant">GL_LEQUAL</code>. See <a href="glTexParameter.xml"><span class="citerefentry"><span class="refentrytitle">glTexParameter</span></span></a>.
 120                     </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
 121             If an error is generated,
 122             no change is made to the contents of <em class="parameter"><code>params</code></em>.
 123         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>
 124             <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
 125             accepted value.
 126         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
 127             <a href="glTexParameter.xml"><span class="citerefentry"><span class="refentrytitle">glTexParameter</span></span></a>
 128         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
 129             Copyright <span class="trademark"></span>© 1991-2006
 130             Silicon Graphics, Inc. Copyright <span class="trademark"></span>© 2010
 131             Khronos Group. This document is licensed under the SGI
 132             Free Software B License. For details, see
 133             <a href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
 134         </p></div></div></body></html>