upstream-doc/man4/glGetBufferParameter.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="glGetBufferParameteriv">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>2005</year>
   9                 <holder>Sams Publishing</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>glGetBufferParameteriv</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>glGetBufferParameteriv</refname>
  17         <refpurpose>return parameters of a buffer object</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>C Specification</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>void <function>glGetBufferParameteriv</function></funcdef>
  23                 <paramdef>GLenum <parameter>target</parameter></paramdef>
  24                 <paramdef>GLenum <parameter>value</parameter></paramdef>
  25                 <paramdef>GLint * <parameter>data</parameter></paramdef>
  26             </funcprototype>
  27         </funcsynopsis>
  28         <funcsynopsis>
  29             <funcprototype>
  30                 <funcdef>void <function>glGetBufferParameteri64v</function></funcdef>
  31                 <paramdef>GLenum <parameter>target</parameter></paramdef>
  32                 <paramdef>GLenum <parameter>value</parameter></paramdef>
  33                 <paramdef>GLint64 * <parameter>data</parameter></paramdef>
  34             </funcprototype>
  35         </funcsynopsis>
  36     </refsynopsisdiv>
  37     <refsect1 id="parameters"><title>Parameters</title>
  38         <variablelist>
  39         <varlistentry>
  40             <term><parameter>target</parameter></term>
  41             <listitem>
  42                 <para>
  43                     Specifies the target buffer object.
  44                     The symbolic constant must be
  45                     <constant>GL_ARRAY_BUFFER</constant>,
  46                     <constant>GL_ATOMIC_COUNTER_BUFFER</constant>,
  47                     <constant>GL_COPY_READ_BUFFER</constant>,
  48                     <constant>GL_COPY_WRITE_BUFFER</constant>,
  49                     <constant>GL_DRAW_INDIRECT_BUFFER</constant>,
  50                     <constant>GL_DISPATCH_INDIRECT_BUFFER</constant>,
  51                     <constant>GL_ELEMENT_ARRAY_BUFFER</constant>,
  52                     <constant>GL_PIXEL_PACK_BUFFER</constant>,
  53                     <constant>GL_PIXEL_UNPACK_BUFFER</constant>,
  54                     <constant>GL_SHADER_STORAGE_BUFFER</constant>,
  55                     <constant>GL_TEXTURE_BUFFER</constant>,
  56                     <constant>GL_TRANSFORM_FEEDBACK_BUFFER</constant>, or
  57                     <constant>GL_UNIFORM_BUFFER</constant>.
  58                 </para>
  59             </listitem>
  60         </varlistentry>
  61         <varlistentry>
  62             <term><parameter>value</parameter></term>
  63             <listitem>
  64                 <para>
  65                     Specifies the symbolic name of a buffer object parameter.
  66                     Accepted values are <constant>GL_BUFFER_ACCESS</constant>, <constant>GL_BUFFER_MAPPED</constant>,
  67                     <constant>GL_BUFFER_SIZE</constant>, or <constant>GL_BUFFER_USAGE</constant>.
  68                 </para>
  69             </listitem>
  70         </varlistentry>
  71         <varlistentry>
  72             <term><parameter>data</parameter></term>
  73             <listitem>
  74                 <para>
  75                     Returns the requested parameter.
  76                 </para>
  77             </listitem>
  78         </varlistentry>
  79         </variablelist>
  80     </refsect1>
  81     <refsect1 id="description"><title>Description</title>
  82         <para>
  83             <function>glGetBufferParameteriv</function> returns in <parameter>data</parameter> a selected parameter of the buffer object
  84             specified by <parameter>target</parameter>.
  85         </para>
  86         <para>
  87             <parameter>value</parameter> names a specific buffer object parameter, as follows:
  88         </para>
  89         <variablelist>
  90             <varlistentry>
  91                 <term><constant>GL_BUFFER_ACCESS</constant></term>
  92                 <listitem>
  93                     <para>
  94                         <parameter>params</parameter> returns the access policy set while mapping the buffer object.
  95                         The initial value is <constant>GL_READ_WRITE</constant>.
  96                     </para>
  97                 </listitem>
  98             </varlistentry>
  99             <varlistentry>
 100                 <term><constant>GL_BUFFER_MAPPED</constant></term>
 101                 <listitem>
 102                     <para>
 103                         <parameter>params</parameter> returns a flag indicating whether the buffer object is currently
 104                         mapped. The initial value is <constant>GL_FALSE</constant>.
 105                     </para>
 106                 </listitem>
 107             </varlistentry>
 108             <varlistentry>
 109                 <term><constant>GL_BUFFER_SIZE</constant></term>
 110                 <listitem>
 111                     <para>
 112                         <parameter>params</parameter> returns the size of the buffer object, measured in bytes.
 113                         The initial value is 0.
 114                     </para>
 115                 </listitem>
 116             </varlistentry>
 117             <varlistentry>
 118                 <term><constant>GL_BUFFER_USAGE</constant></term>
 119                 <listitem>
 120                     <para>
 121                         <parameter>params</parameter> returns the buffer object's usage pattern.  The initial value is
 122                         <constant>GL_STATIC_DRAW</constant>.
 123                     </para>
 124                 </listitem>
 125             </varlistentry>
 126         </variablelist>
 127     </refsect1>
 128     <refsect1 id="notes"><title>Notes</title>
 129         <para>
 130             If an error is generated,
 131             no change is made to the contents of <parameter>data</parameter>.
 132         </para>
 133         <para>
 134             The <constant>GL_ATOMIC_COUNTER_BUFER</constant> target is available only if the GL version is 4.2 or greater.
 135         </para>
 136         <para>
 137             The <constant>GL_DISPATCH_INDIRECT_BUFFER</constant> and <constant>GL_SHADER_STORAGE_BUFFER</constant> targets are available only if the GL version is 4.3 or greater.
 138         </para>
 139     </refsect1>
 140     <refsect1 id="errors"><title>Errors</title>
 141         <para>
 142             <constant>GL_INVALID_ENUM</constant> is generated if <parameter>target</parameter> or <parameter>value</parameter> is not an
 143             accepted value.
 144         </para>
 145         <para>
 146             <constant>GL_INVALID_OPERATION</constant> is generated if the reserved buffer object name 0 is bound to <parameter>target</parameter>.
 147         </para>
 148     </refsect1>
 149     <refsect1 id="seealso"><title>See Also</title>
 150         <para>
 151             <citerefentry><refentrytitle>glBindBuffer</refentrytitle></citerefentry>,
 152             <citerefentry><refentrytitle>glBufferData</refentrytitle></citerefentry>,
 153             <citerefentry><refentrytitle>glMapBuffer</refentrytitle></citerefentry>,
 154             <citerefentry><refentrytitle>glUnmapBuffer</refentrytitle></citerefentry>
 155         </para>
 156     </refsect1>
 157     <refsect1 id="Copyright"><title>Copyright</title>
 158         <para>
 159             Copyright <trademark class="copyright"></trademark> 2005 Addison-Wesley.
 160             Copyright <trademark class="copyright"></trademark> 2010-2013 Khronos Group.
 161             This material may be distributed subject to the terms and conditions set forth in
 162             the Open Publication License, v 1.0, 8 June 1999.
 163             <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.
 164         </para>
 165     </refsect1>
 166 </refentry>