upstream-man-pages/man4/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 4 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>,
  12                     <code class="constant">GL_TEXTURE_CUBE_MAP</code>, and
  13                     <code class="constant">GL_TEXTURE_CUBE_MAP_ARRAY</code>
  14                     are accepted.
  15                 </p></dd><dt><span class="term"><em class="parameter"><code>pname</code></em></span></dt><dd><p>
  16                     Specifies the symbolic name of a texture parameter.
  17                     <code class="constant">GL_DEPTH_STENCIL_TEXTURE_MODE</code>,
  18                     <code class="constant">GL_TEXTURE_BASE_LEVEL</code>,
  19                     <code class="constant">GL_TEXTURE_BORDER_COLOR</code>,
  20                     <code class="constant">GL_TEXTURE_COMPARE_MODE</code>,
  21                     <code class="constant">GL_TEXTURE_COMPARE_FUNC</code>,
  22                     <code class="constant">GL_TEXTURE_IMMUTABLE_FORMAT</code>,
  23                     <code class="constant">GL_TEXTURE_IMMUTABLE_LEVELS</code>,
  24                     <code class="constant">GL_TEXTURE_LOD_BIAS</code>,
  25                     <code class="constant">GL_TEXTURE_MAG_FILTER</code>,
  26                     <code class="constant">GL_TEXTURE_MAX_LEVEL</code>,
  27                     <code class="constant">GL_TEXTURE_MAX_LOD</code>,
  28                     <code class="constant">GL_TEXTURE_MIN_FILTER</code>,
  29                     <code class="constant">GL_TEXTURE_MIN_LOD</code>,
  30                     <code class="constant">GL_TEXTURE_SWIZZLE_R</code>,
  31                     <code class="constant">GL_TEXTURE_SWIZZLE_G</code>,
  32                     <code class="constant">GL_TEXTURE_SWIZZLE_B</code>,
  33                     <code class="constant">GL_TEXTURE_SWIZZLE_A</code>,
  34                     <code class="constant">GL_TEXTURE_SWIZZLE_RGBA</code>,
  35                     <code class="constant">GL_TEXTURE_VIEW_MIN_LAYER</code>,
  36                     <code class="constant">GL_TEXTURE_VIEW_MIN_LEVEL</code>,
  37                     <code class="constant">GL_TEXTURE_VIEW_NUM_LAYERS</code>,
  38                     <code class="constant">GL_TEXTURE_VIEW_NUM_LEVELS</code>,
  39                     <code class="constant">GL_TEXTURE_WRAP_S</code>,
  40                     <code class="constant">GL_TEXTURE_WRAP_T</code>, and
  41                     <code class="constant">GL_TEXTURE_WRAP_R</code>
  42                     are accepted.
  43                 </p></dd><dt><span class="term"><em class="parameter"><code>params</code></em></span></dt><dd><p>
  44                     Returns the texture parameters.
  45                 </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
  46             <code class="function">glGetTexParameter</code> returns in <em class="parameter"><code>params</code></em> the value or values of the texture parameter
  47             specified as <em class="parameter"><code>pname</code></em>.
  48             <em class="parameter"><code>target</code></em> defines the target texture.
  49             <code class="constant">GL_TEXTURE_1D</code>,
  50             <code class="constant">GL_TEXTURE_2D</code>,
  51             <code class="constant">GL_TEXTURE_3D</code>,
  52             <code class="constant">GL_TEXTURE_1D_ARRAY</code>,
  53             <code class="constant">GL_TEXTURE_2D_ARRAY</code>,
  54             <code class="constant">GL_TEXTURE_RECTANGLE</code>,
  55             <code class="constant">GL_TEXTURE_CUBE_MAP</code>,
  56             <code class="constant">GL_TEXTURE_CUBE_MAP_ARRAY</code>
  57             specify one-, two-, or three-dimensional, one-dimensional array, two-dimensional array, rectangle, cube-mapped or cube-mapped array texturing, respectively.
  58             <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>,
  59             with the same interpretations:
  60         </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_DEPTH_STENCIL_TEXTURE_MODE</code></span></dt><dd><p>
  61                         Returns the single-value depth stencil texture mode, a symbolic constant.
  62                         The initial value is <code class="constant">GL_DEPTH_COMPONENT</code>.
  63                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_MAG_FILTER</code></span></dt><dd><p>
  64                         Returns the single-valued texture magnification filter,
  65                         a symbolic constant. The initial value is <code class="constant">GL_LINEAR</code>.
  66                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_MIN_FILTER</code></span></dt><dd><p>
  67                         Returns the single-valued texture minification filter,
  68                         a symbolic constant. The initial value is <code class="constant">GL_NEAREST_MIPMAP_LINEAR</code>.
  69                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_MIN_LOD</code></span></dt><dd><p>
  70                         Returns the single-valued texture minimum level-of-detail value.  The
  71                         initial value is
  72                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  73
  74                             <mml:mn>-1000</mml:mn>
  75                         </mml:math>.
  76                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_MAX_LOD</code></span></dt><dd><p>
  77                         Returns the single-valued texture maximum level-of-detail value. The
  78                         initial value is 1000.
  79                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_BASE_LEVEL</code></span></dt><dd><p>
  80                         Returns the single-valued base texture mipmap level.  The initial value is 0.
  81                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_MAX_LEVEL</code></span></dt><dd><p>
  82                         Returns the single-valued maximum texture mipmap array level.  The initial
  83                         value is 1000.
  84                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_SWIZZLE_R</code></span></dt><dd><p>
  85                         Returns the red component swizzle. The initial value is <code class="constant">GL_RED</code>.
  86                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_SWIZZLE_G</code></span></dt><dd><p>
  87                         Returns the green component swizzle. The initial value is <code class="constant">GL_GREEN</code>.
  88                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_SWIZZLE_B</code></span></dt><dd><p>
  89                         Returns the blue component swizzle. The initial value is <code class="constant">GL_BLUE</code>.
  90                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_SWIZZLE_A</code></span></dt><dd><p>
  91                         Returns the alpha component swizzle. The initial value is <code class="constant">GL_ALPHA</code>.
  92                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_SWIZZLE_RGBA</code></span></dt><dd><p>
  93                         Returns the component swizzle for all channels in a single query.
  94                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_WRAP_S</code></span></dt><dd><p>
  95                         Returns the single-valued wrapping function for texture coordinate
  96                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>,
  97                         a symbolic constant. The initial value is <code class="constant">GL_REPEAT</code>.
  98                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_WRAP_T</code></span></dt><dd><p>
  99                         Returns the single-valued wrapping function for texture coordinate
 100                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">t</mml:mi></mml:math>,
 101                         a symbolic constant. The initial value is <code class="constant">GL_REPEAT</code>.
 102                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_WRAP_R</code></span></dt><dd><p>
 103                         Returns the single-valued wrapping function for texture coordinate
 104                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">r</mml:mi></mml:math>,
 105                         a symbolic constant. The initial value is <code class="constant">GL_REPEAT</code>.
 106                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_BORDER_COLOR</code></span></dt><dd><p>
 107                         Returns four integer or floating-point numbers that comprise the RGBA color
 108                         of the texture border.
 109                         Floating-point values are returned in the range
 110                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 111
 112                             <mml:mfenced open="[" close="]">
 113                                 <mml:mn>0</mml:mn>
 114                                 <mml:mn>1</mml:mn>
 115                             </mml:mfenced>
 116                         </mml:math>.
 117                         Integer values are returned as a linear mapping of the internal floating-point
 118                         representation such that 1.0 maps to the most positive representable
 119                         integer and
 120                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 121
 122                             <mml:mn>-1.0</mml:mn>
 123                         </mml:math>
 124                         maps to the most negative representable
 125                         integer. The initial value is (0, 0, 0, 0).
 126                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_COMPARE_MODE</code></span></dt><dd><p>
 127                         Returns a single-valued texture comparison mode, a symbolic constant.  The
 128                         initial value is <code class="constant">GL_NONE</code>. See <a href="glTexParameter.xml"><span class="citerefentry"><span class="refentrytitle">glTexParameter</span></span></a>.
 129                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_COMPARE_FUNC</code></span></dt><dd><p>
 130                         Returns a single-valued texture comparison function, a symbolic constant.  The
 131                         initial value is <code class="constant">GL_LEQUAL</code>. See <a href="glTexParameter.xml"><span class="citerefentry"><span class="refentrytitle">glTexParameter</span></span></a>.
 132                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_VIEW_MIN_LEVEL</code></span></dt><dd><p>
 133                         Returns a single-valued base level of a texture view relative to its parent.  The
 134                         initial value is 0. See <a href="glTextureView.xml"><span class="citerefentry"><span class="refentrytitle">glTextureView</span></span></a>.
 135                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_VIEW_NUM_LEVELS</code></span></dt><dd><p>
 136                         Returns a single-valued number of levels of detail of a texture view.
 137                         See <a href="glTextureView.xml"><span class="citerefentry"><span class="refentrytitle">glTextureView</span></span></a>.
 138                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_VIEW_MIN_LAYER</code></span></dt><dd><p>
 139                         Returns a single-valued first level of a texture array view relative to its parent.
 140                         See <a href="glTextureView.xml"><span class="citerefentry"><span class="refentrytitle">glTextureView</span></span></a>.
 141                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_VIEW_NUM_LAYERS</code></span></dt><dd><p>
 142                         Returns a single-valued number of layers in a texture array view.
 143                         See <a href="glTextureView.xml"><span class="citerefentry"><span class="refentrytitle">glTextureView</span></span></a>.
 144                     </p></dd><dt><span class="term"><code class="constant">GL_TEXTURE_IMMUTABLE_LEVELS</code></span></dt><dd><p>
 145                         Returns a single-valued number of immutable texture levels in a texture view.
 146                         See <a href="glTextureView.xml"><span class="citerefentry"><span class="refentrytitle">glTextureView</span></span></a>.
 147                     </p></dd></dl></div><p>
 148         In addition to the parameters that may be set with <a href="glTexParameter.xml"><span class="citerefentry"><span class="refentrytitle">glTexParameter</span></span></a>,
 149         <code class="function">glGetTexParameter</code> accepts the following read-only parameters:
 150     </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_TEXTURE_IMMUTABLE_FORMAT</code></span></dt><dd><p>
 151                         Returns non-zero if the texture has an immutable format. Textures become
 152                         immutable if their storage is specified with <a href="glTexStorage1D.xml"><span class="citerefentry"><span class="refentrytitle">glTexStorage1D</span></span></a>,
 153                         <a href="glTexStorage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexStorage2D</span></span></a> or <a href="glTexStorage3D.xml"><span class="citerefentry"><span class="refentrytitle">glTexStorage3D</span></span></a>.
 154                         The initial value is <code class="constant">GL_FALSE</code>.
 155                     </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
 156             If an error is generated,
 157             no change is made to the contents of <em class="parameter"><code>params</code></em>.
 158         </p><p>
 159             <code class="constant">GL_DEPTH_STENCIL_TEXTURE_MODE</code>, <code class="constant">GL_TEXTURE_VIEW_MIN_LEVEL</code>,
 160             <code class="constant">GL_TEXTURE_VIEW_NUM_LEVELS</code>, <code class="constant">GL_TEXTURE_VIEW_MIN_LAYER</code>,
 161             <code class="constant">GL_TEXTURE_VIEW_NUM_LAYERS</code> and <code class="constant">GL_TEXTURE_IMMUTABLE_LEVELS</code> are available only if the GL version is 4.3 or greater.
 162         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>
 163             <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
 164             accepted value.
 165         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
 166             <a href="glTexParameter.xml"><span class="citerefentry"><span class="refentrytitle">glTexParameter</span></span></a>,
 167             <a href="glTexStorage1D.xml"><span class="citerefentry"><span class="refentrytitle">glTexStorage1D</span></span></a>,
 168             <a href="glTexStorage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexStorage2D</span></span></a>,
 169             <a href="glTexStorage3D.xml"><span class="citerefentry"><span class="refentrytitle">glTexStorage3D</span></span></a>,
 170             <a href="glTextureView.xml"><span class="citerefentry"><span class="refentrytitle">glTextureView</span></span></a>
 171         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
 172             Copyright <span class="trademark"></span>© 1991-2006
 173             Silicon Graphics, Inc. Copyright <span class="trademark"></span>© 2010-2012
 174             Khronos Group. This document is licensed under the SGI
 175             Free Software B License. For details, see
 176             <a href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
 177         </p></div></div></body></html>