upstream-man-pages/man3/glGetTexParameter.xml

   1 <?xml version="1.0" encoding="UTF-8"?>
   2 <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN"
   3               "http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd">
   4 <refentry id="glGetTexParameter">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>1991-2006</year>
   9                 <holder>Silicon Graphics, Inc.</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>glGetTexParameter</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>glGetTexParameter</refname>
  17         <refpurpose>return texture parameter values</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>C Specification</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>void <function>glGetTexParameterfv</function></funcdef>
  23                 <paramdef>GLenum <parameter>target</parameter></paramdef>
  24                 <paramdef>GLenum <parameter>pname</parameter></paramdef>
  25                 <paramdef>GLfloat * <parameter>params</parameter></paramdef>
  26             </funcprototype>
  27         </funcsynopsis>
  28         <funcsynopsis>
  29             <funcprototype>
  30                 <funcdef>void <function>glGetTexParameteriv</function></funcdef>
  31                 <paramdef>GLenum <parameter>target</parameter></paramdef>
  32                 <paramdef>GLenum <parameter>pname</parameter></paramdef>
  33                 <paramdef>GLint * <parameter>params</parameter></paramdef>
  34             </funcprototype>
  35         </funcsynopsis>
  36         <funcsynopsis>
  37             <funcprototype>
  38                 <funcdef>void <function>glGetTexParameterIiv</function></funcdef>
  39                 <paramdef>GLenum <parameter>target</parameter></paramdef>
  40                 <paramdef>GLenum <parameter>pname</parameter></paramdef>
  41                 <paramdef>GLint * <parameter>params</parameter></paramdef>
  42             </funcprototype>
  43         </funcsynopsis>
  44         <funcsynopsis>
  45             <funcprototype>
  46                 <funcdef>void <function>glGetTexParameterIuiv</function></funcdef>
  47                 <paramdef>GLenum <parameter>target</parameter></paramdef>
  48                 <paramdef>GLenum <parameter>pname</parameter></paramdef>
  49                 <paramdef>GLuint * <parameter>params</parameter></paramdef>
  50             </funcprototype>
  51         </funcsynopsis>
  52     </refsynopsisdiv>
  53     <!-- eqn: ignoring delim $$ -->
  54     <refsect1 id="parameters"><title>Parameters</title>
  55         <variablelist>
  56         <varlistentry>
  57             <term><parameter>target</parameter></term>
  58             <listitem>
  59                 <para>
  60                     Specifies the symbolic name of the target texture.
  61                     <constant>GL_TEXTURE_1D</constant>,
  62                     <constant>GL_TEXTURE_2D</constant>,
  63                     <constant>GL_TEXTURE_1D_ARRAY</constant>,
  64                     <constant>GL_TEXTURE_2D_ARRAY</constant>,
  65                     <constant>GL_TEXTURE_3D</constant>,
  66                     <constant>GL_TEXTURE_RECTANGLE</constant>, and
  67                     <constant>GL_TEXTURE_CUBE_MAP</constant>
  68                     are accepted.
  69                 </para>
  70             </listitem>
  71         </varlistentry>
  72         <varlistentry>
  73             <term><parameter>pname</parameter></term>
  74             <listitem>
  75                 <para>
  76                     Specifies the symbolic name of a texture parameter.
  77                     <constant>GL_TEXTURE_BASE_LEVEL</constant>,
  78                     <constant>GL_TEXTURE_BORDER_COLOR</constant>,
  79                     <constant>GL_TEXTURE_COMPARE_MODE</constant>,
  80                     <constant>GL_TEXTURE_COMPARE_FUNC</constant>,
  81                     <constant>GL_TEXTURE_LOD_BIAS</constant>,
  82                     <constant>GL_TEXTURE_MAG_FILTER</constant>,
  83                     <constant>GL_TEXTURE_MAX_LEVEL</constant>,
  84                     <constant>GL_TEXTURE_MAX_LOD</constant>,
  85                     <constant>GL_TEXTURE_MIN_FILTER</constant>,
  86                     <constant>GL_TEXTURE_MIN_LOD</constant>,
  87                     <constant>GL_TEXTURE_SWIZZLE_R</constant>,
  88                     <constant>GL_TEXTURE_SWIZZLE_G</constant>,
  89                     <constant>GL_TEXTURE_SWIZZLE_B</constant>,
  90                     <constant>GL_TEXTURE_SWIZZLE_A</constant>,
  91                     <constant>GL_TEXTURE_SWIZZLE_RGBA</constant>,
  92                     <constant>GL_TEXTURE_WRAP_S</constant>,
  93                     <constant>GL_TEXTURE_WRAP_T</constant>, and
  94                     <constant>GL_TEXTURE_WRAP_R</constant>
  95                     are accepted.
  96                 </para>
  97             </listitem>
  98         </varlistentry>
  99         <varlistentry>
 100             <term><parameter>params</parameter></term>
 101             <listitem>
 102                 <para>
 103                     Returns the texture parameters.
 104                 </para>
 105             </listitem>
 106         </varlistentry>
 107         </variablelist>
 108     </refsect1>
 109     <refsect1 id="description"><title>Description</title>
 110         <para>
 111             <function>glGetTexParameter</function> returns in <parameter>params</parameter> the value or values of the texture parameter
 112             specified as <parameter>pname</parameter>.
 113             <parameter>target</parameter> defines the target texture.
 114             <constant>GL_TEXTURE_1D</constant>,
 115             <constant>GL_TEXTURE_2D</constant>,
 116             <constant>GL_TEXTURE_3D</constant>,
 117             <constant>GL_TEXTURE_1D_ARRAY</constant>,
 118             <constant>GL_TEXTURE_2D_ARRAY</constant>,
 119             <constant>GL_TEXTURE_RECTANGLE</constant>, and
 120             <constant>GL_TEXTURE_CUBE_MAP</constant>
 121             specify one-, two-, or three-dimensional, one-dimensional array, two-dimensional array, rectangle or cube-mapped texturing, respectively.
 122             <parameter>pname</parameter> accepts the same symbols as <citerefentry><refentrytitle>glTexParameter</refentrytitle></citerefentry>,
 123             with the same interpretations:
 124         </para>
 125         <variablelist>
 126             <varlistentry>
 127                 <term><constant>GL_TEXTURE_MAG_FILTER</constant></term>
 128                 <listitem>
 129                     <para>
 130                         Returns the single-valued texture magnification filter,
 131                         a symbolic constant. The initial value is <constant>GL_LINEAR</constant>.
 132                     </para>
 133                 </listitem>
 134             </varlistentry>
 135             <varlistentry>
 136                 <term><constant>GL_TEXTURE_MIN_FILTER</constant></term>
 137                 <listitem>
 138                     <para>
 139                         Returns the single-valued texture minification filter,
 140                         a symbolic constant. The initial value is <constant>GL_NEAREST_MIPMAP_LINEAR</constant>.
 141                     </para>
 142                 </listitem>
 143             </varlistentry>
 144             <varlistentry>
 145                 <term><constant>GL_TEXTURE_MIN_LOD</constant></term>
 146                 <listitem>
 147                     <para>
 148                         Returns the single-valued texture minimum level-of-detail value.  The
 149                         initial value is
 150                         <inlineequation><mml:math>
 151                             <!-- eqn: -1000: -->
 152                             <mml:mn>-1000</mml:mn>
 153                         </mml:math></inlineequation>.
 154                     </para>
 155                 </listitem>
 156             </varlistentry>
 157             <varlistentry>
 158                 <term><constant>GL_TEXTURE_MAX_LOD</constant></term>
 159                 <listitem>
 160                     <para>
 161                         Returns the single-valued texture maximum level-of-detail value. The
 162                         initial value is 1000.
 163                     </para>
 164                 </listitem>
 165             </varlistentry>
 166             <varlistentry>
 167                 <term><constant>GL_TEXTURE_BASE_LEVEL</constant></term>
 168                 <listitem>
 169                     <para>
 170                         Returns the single-valued base texture mipmap level.  The initial value is 0.
 171                     </para>
 172                 </listitem>
 173             </varlistentry>
 174             <varlistentry>
 175                 <term><constant>GL_TEXTURE_MAX_LEVEL</constant></term>
 176                 <listitem>
 177                     <para>
 178                         Returns the single-valued maximum texture mipmap array level.  The initial
 179                         value is 1000.
 180                     </para>
 181                 </listitem>
 182             </varlistentry>
 183             <varlistentry>
 184                 <term><constant>GL_TEXTURE_SWIZZLE_R</constant></term>
 185                 <listitem>
 186                     <para>
 187                         Returns the red component swizzle. The initial value is <constant>GL_RED</constant>.
 188                     </para>
 189                 </listitem>
 190             </varlistentry>
 191             <varlistentry>
 192                 <term><constant>GL_TEXTURE_SWIZZLE_G</constant></term>
 193                 <listitem>
 194                     <para>
 195                         Returns the green component swizzle. The initial value is <constant>GL_GREEN</constant>.
 196                     </para>
 197                 </listitem>
 198             </varlistentry>
 199             <varlistentry>
 200                 <term><constant>GL_TEXTURE_SWIZZLE_B</constant></term>
 201                 <listitem>
 202                     <para>
 203                         Returns the blue component swizzle. The initial value is <constant>GL_BLUE</constant>.
 204                     </para>
 205                 </listitem>
 206             </varlistentry>
 207             <varlistentry>
 208                 <term><constant>GL_TEXTURE_SWIZZLE_A</constant></term>
 209                 <listitem>
 210                     <para>
 211                         Returns the alpha component swizzle. The initial value is <constant>GL_ALPHA</constant>.
 212                     </para>
 213                 </listitem>
 214             </varlistentry>
 215             <varlistentry>
 216                 <term><constant>GL_TEXTURE_SWIZZLE_RGBA</constant></term>
 217                 <listitem>
 218                     <para>
 219                         Returns the component swizzle for all channels in a single query.
 220                     </para>
 221                 </listitem>
 222             </varlistentry>
 223             <varlistentry>
 224                 <term><constant>GL_TEXTURE_WRAP_S</constant></term>
 225                 <listitem>
 226                     <para>
 227                         Returns the single-valued wrapping function for texture coordinate
 228                         <inlineequation><mml:math><mml:mi mathvariant="italic">s</mml:mi></mml:math></inlineequation>,
 229                         a symbolic constant. The initial value is <constant>GL_REPEAT</constant>.
 230                     </para>
 231                 </listitem>
 232             </varlistentry>
 233             <varlistentry>
 234                 <term><constant>GL_TEXTURE_WRAP_T</constant></term>
 235                 <listitem>
 236                     <para>
 237                         Returns the single-valued wrapping function for texture coordinate
 238                         <inlineequation><mml:math><mml:mi mathvariant="italic">t</mml:mi></mml:math></inlineequation>,
 239                         a symbolic constant. The initial value is <constant>GL_REPEAT</constant>.
 240                     </para>
 241                 </listitem>
 242             </varlistentry>
 243             <varlistentry>
 244                 <term><constant>GL_TEXTURE_WRAP_R</constant></term>
 245                 <listitem>
 246                     <para>
 247                         Returns the single-valued wrapping function for texture coordinate
 248                         <inlineequation><mml:math><mml:mi mathvariant="italic">r</mml:mi></mml:math></inlineequation>,
 249                         a symbolic constant. The initial value is <constant>GL_REPEAT</constant>.
 250                     </para>
 251                 </listitem>
 252             </varlistentry>
 253             <varlistentry>
 254                 <term><constant>GL_TEXTURE_BORDER_COLOR</constant></term>
 255                 <listitem>
 256                     <para>
 257                         Returns four integer or floating-point numbers that comprise the RGBA color
 258                         of the texture border.
 259                         Floating-point values are returned in the range
 260                         <inlineequation><mml:math>
 261                             <!-- eqn: [0,1]: -->
 262                             <mml:mfenced open="[" close="]">
 263                                 <mml:mn>0</mml:mn>
 264                                 <mml:mn>1</mml:mn>
 265                             </mml:mfenced>
 266                         </mml:math></inlineequation>.
 267                         Integer values are returned as a linear mapping of the internal floating-point
 268                         representation such that 1.0 maps to the most positive representable
 269                         integer and
 270                         <inlineequation><mml:math>
 271                             <!-- eqn: -1.0: -->
 272                             <mml:mn>-1.0</mml:mn>
 273                         </mml:math></inlineequation>
 274                         maps to the most negative representable
 275                         integer. The initial value is (0, 0, 0, 0).
 276                     </para>
 277                 </listitem>
 278             </varlistentry>
 279             <varlistentry>
 280                 <term><constant>GL_TEXTURE_COMPARE_MODE</constant></term>
 281                 <listitem>
 282                     <para>
 283                         Returns a single-valued texture comparison mode, a symbolic constant.  The
 284                         initial value is <constant>GL_NONE</constant>. See <citerefentry><refentrytitle>glTexParameter</refentrytitle></citerefentry>.
 285                     </para>
 286                 </listitem>
 287             </varlistentry>
 288             <varlistentry>
 289                 <term><constant>GL_TEXTURE_COMPARE_FUNC</constant></term>
 290                 <listitem>
 291                     <para>
 292                         Returns a single-valued texture comparison function, a symbolic constant.  The
 293                         initial value is <constant>GL_LEQUAL</constant>. See <citerefentry><refentrytitle>glTexParameter</refentrytitle></citerefentry>.
 294                     </para>
 295                 </listitem>
 296             </varlistentry>
 297         </variablelist>
 298     </refsect1>
 299     <refsect1 id="notes"><title>Notes</title>
 300         <para>
 301             If an error is generated,
 302             no change is made to the contents of <parameter>params</parameter>.
 303         </para>
 304     </refsect1>
 305     <refsect1 id="errors"><title>Errors</title>
 306         <para>
 307             <constant>GL_INVALID_ENUM</constant> is generated if <parameter>target</parameter> or <parameter>pname</parameter> is not an
 308             accepted value.
 309         </para>
 310     </refsect1>
 311     <refsect1 id="seealso"><title>See Also</title>
 312         <para>
 313             <citerefentry><refentrytitle>glTexParameter</refentrytitle></citerefentry>
 314         </para>
 315     </refsect1>
 316     <refsect1 id="Copyright"><title>Copyright</title>
 317         <para>
 318             Copyright <trademark class="copyright"></trademark> 1991-2006
 319             Silicon Graphics, Inc. Copyright <trademark class="copyright"></trademark> 2010
 320             Khronos Group. This document is licensed under the SGI
 321             Free Software B License. For details, see
 322             <ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>.
 323         </para>
 324     </refsect1>
 325 </refentry>