upstream-man-pages/man2/glAreTexturesResident.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="glAreTexturesResident">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>1991-2006</year>
   9                 <holder>Silicon Graphics, Inc.</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>glAreTexturesResident</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>glAreTexturesResident</refname>
  17         <refpurpose>determine if textures are loaded in texture memory</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>C Specification</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>GLboolean <function>glAreTexturesResident</function></funcdef>
  23                 <paramdef>GLsizei <parameter>n</parameter></paramdef>
  24                 <paramdef>const GLuint * <parameter>textures</parameter></paramdef>
  25                 <paramdef>GLboolean * <parameter>residences</parameter></paramdef>
  26             </funcprototype>
  27         </funcsynopsis>
  28     </refsynopsisdiv>
  29     <refsect1 id="parameters"><title>Parameters</title>
  30         <variablelist>
  31         <varlistentry>
  32             <term><parameter>n</parameter></term>
  33             <listitem>
  34                 <para>
  35                     Specifies the number of textures to be queried.
  36                 </para>
  37             </listitem>
  38         </varlistentry>
  39         <varlistentry>
  40             <term><parameter>textures</parameter></term>
  41             <listitem>
  42                 <para>
  43                     Specifies an array containing the names of the textures to be queried.
  44                 </para>
  45             </listitem>
  46         </varlistentry>
  47         <varlistentry>
  48             <term><parameter>residences</parameter></term>
  49             <listitem>
  50                 <para>
  51                     Specifies an array in which the texture residence status is returned.
  52                     The residence status of a texture named by an element of <parameter>textures</parameter> is
  53                     returned in the corresponding element of <parameter>residences</parameter>.
  54                 </para>
  55             </listitem>
  56         </varlistentry>
  57         </variablelist>
  58     </refsect1>
  59     <refsect1 id="description"><title>Description</title>
  60         <para>
  61             GL establishes
  62             a ``working set'' of textures that are resident in texture memory.
  63             These textures can be bound to a texture target much more efficiently
  64             than textures that are not resident.
  65         </para>
  66         <para>
  67             <function>glAreTexturesResident</function> queries the texture residence status of the <parameter>n</parameter> textures named by
  68             the elements of <parameter>textures</parameter>.
  69             If all the named textures are resident,
  70             <function>glAreTexturesResident</function> returns <constant>GL_TRUE</constant>,
  71             and the contents of <parameter>residences</parameter> are undisturbed.
  72             If not all the named textures are resident, <function>glAreTexturesResident</function> returns <constant>GL_FALSE</constant>,
  73             and detailed status is returned in the <parameter>n</parameter> elements of <parameter>residences</parameter>.
  74             If an element of <parameter>residences</parameter> is <constant>GL_TRUE</constant>, then the texture named by
  75             the corresponding element of <parameter>textures</parameter> is resident.
  76         </para>
  77         <para>
  78             The residence status of a single bound texture may also be queried
  79             by calling
  80             <citerefentry><refentrytitle>glGetTexParameter</refentrytitle></citerefentry> with the <emphasis>target</emphasis> argument set to the
  81             target to which the texture is bound, and the <emphasis>pname</emphasis> argument
  82             set to <constant>GL_TEXTURE_RESIDENT</constant>.
  83             This is the only way that the residence status of a default texture can be
  84             queried.
  85         </para>
  86     </refsect1>
  87     <refsect1 id="notes"><title>Notes</title>
  88         <para>
  89             <function>glAreTexturesResident</function> is available only if the GL version is 1.1 or greater.
  90         </para>
  91         <para>
  92             <function>glAreTexturesResident</function> returns the residency status of the textures at the time of
  93             invocation. It does not guarantee that the textures will remain
  94             resident at any other time.
  95         </para>
  96         <para>
  97             If textures reside in virtual memory (there is no texture memory), they
  98             are considered always resident.
  99         </para>
 100         <para>
 101             Some implementations may not load a texture until the first use of
 102             that texture.
 103         </para>
 104     </refsect1>
 105     <refsect1 id="errors"><title>Errors</title>
 106         <para>
 107             <constant>GL_INVALID_VALUE</constant> is generated if <parameter>n</parameter> is negative.
 108         </para>
 109         <para>
 110             <constant>GL_INVALID_VALUE</constant> is generated if any element in <parameter>textures</parameter>
 111             is 0 or does not name a texture. In that case, the function returns
 112             <constant>GL_FALSE</constant> and the contents of <parameter>residences</parameter> is indeterminate.
 113         </para>
 114         <para>
 115             <constant>GL_INVALID_OPERATION</constant> is generated if <function>glAreTexturesResident</function> is executed
 116             between the execution of <citerefentry><refentrytitle>glBegin</refentrytitle></citerefentry> and the corresponding
 117             execution of <citerefentry><refentrytitle>glEnd</refentrytitle></citerefentry>.
 118         </para>
 119     </refsect1>
 120     <refsect1 id="associatedgets"><title>Associated Gets</title>
 121         <para>
 122             <citerefentry><refentrytitle>glGetTexParameter</refentrytitle></citerefentry> with parameter name <constant>GL_TEXTURE_RESIDENT</constant>
 123             retrieves the residence status of a currently bound texture.
 124         </para>
 125     </refsect1>
 126     <refsect1 id="seealso"><title>See Also</title>
 127         <para>
 128             <citerefentry><refentrytitle>glBindTexture</refentrytitle></citerefentry>,
 129             <citerefentry><refentrytitle>glGetTexParameter</refentrytitle></citerefentry>,
 130             <citerefentry><refentrytitle>glPrioritizeTextures</refentrytitle></citerefentry>,
 131             <citerefentry><refentrytitle>glTexImage1D</refentrytitle></citerefentry>,
 132             <citerefentry><refentrytitle>glTexImage2D</refentrytitle></citerefentry>,
 133             <citerefentry><refentrytitle>glTexImage3D</refentrytitle></citerefentry>,
 134             <citerefentry><refentrytitle>glTexParameter</refentrytitle></citerefentry>
 135         </para>
 136     </refsect1>
 137     <refsect1 id="Copyright"><title>Copyright</title>
 138         <para>
 139             Copyright <trademark class="copyright"></trademark> 1991-2006
 140             Silicon Graphics, Inc. This document is licensed under the SGI
 141             Free Software B License. For details, see
 142             <ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>.
 143         </para>
 144     </refsect1>
 145 </refentry>