upstream-man-pages/man4/glGetBufferSubData.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="glGetBufferSubData">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>2005</year>
   9                 <holder>Sams Publishing</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>glGetBufferSubData</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>glGetBufferSubData</refname>
  17         <refpurpose>returns a subset of a buffer object's data store</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>C Specification</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>void <function>glGetBufferSubData</function></funcdef>
  23                 <paramdef>GLenum <parameter>target</parameter></paramdef>
  24                 <paramdef>GLintptr <parameter>offset</parameter></paramdef>
  25                 <paramdef>GLsizeiptr <parameter>size</parameter></paramdef>
  26                 <paramdef>GLvoid * <parameter>data</parameter></paramdef>
  27             </funcprototype>
  28         </funcsynopsis>
  29     </refsynopsisdiv>
  30     <!-- eqn: ignoring delim $$ -->
  31     <refsect1 id="parameters"><title>Parameters</title>
  32         <variablelist>
  33         <varlistentry>
  34             <term><parameter>target</parameter></term>
  35             <listitem>
  36                 <para>
  37                     Specifies the target buffer object.
  38                     The symbolic constant must be
  39                     <constant>GL_ARRAY_BUFFER</constant>,
  40                     <constant>GL_ATOMIC_COUNTER_BUFFER</constant>,
  41                     <constant>GL_COPY_READ_BUFFER</constant>,
  42                     <constant>GL_COPY_WRITE_BUFFER</constant>,
  43                     <constant>GL_DRAW_INDIRECT_BUFFER</constant>,
  44                     <constant>GL_DISPATCH_INDIRECT_BUFFER</constant>,
  45                     <constant>GL_ELEMENT_ARRAY_BUFFER</constant>,
  46                     <constant>GL_PIXEL_PACK_BUFFER</constant>,
  47                     <constant>GL_PIXEL_UNPACK_BUFFER</constant>,
  48                     <constant>GL_TEXTURE_BUFFER</constant>,
  49                     <constant>GL_TRANSFORM_FEEDBACK_BUFFER</constant>, or
  50                     <constant>GL_UNIFORM_BUFFER</constant>.
  51                 </para>
  52             </listitem>
  53         </varlistentry>
  54         <varlistentry>
  55             <term><parameter>offset</parameter></term>
  56             <listitem>
  57                 <para>
  58                     Specifies the offset into the buffer object's data store from which data will be returned,
  59                     measured in bytes.
  60                 </para>
  61             </listitem>
  62         </varlistentry>
  63         <varlistentry>
  64             <term><parameter>size</parameter></term>
  65             <listitem>
  66                 <para>
  67                     Specifies the size in bytes of the data store region being returned.
  68                 </para>
  69             </listitem>
  70         </varlistentry>
  71         <varlistentry>
  72             <term><parameter>data</parameter></term>
  73             <listitem>
  74                 <para>
  75                     Specifies a pointer to the location where buffer object data is returned.
  76                 </para>
  77             </listitem>
  78         </varlistentry>
  79         </variablelist>
  80     </refsect1>
  81     <refsect1 id="description"><title>Description</title>
  82         <para>
  83             <function>glGetBufferSubData</function> returns some or all of the data from the buffer object currently
  84             bound to <parameter>target</parameter>. Data starting at byte offset <parameter>offset</parameter> and
  85             extending for <parameter>size</parameter> bytes is copied from the data store to the memory pointed to by
  86             <parameter>data</parameter>. An error is thrown if the buffer object is currently mapped, or if
  87             <parameter>offset</parameter> and <parameter>size</parameter> together define a range beyond the bounds
  88             of the buffer object's data store.
  89         </para>
  90     </refsect1>
  91     <refsect1 id="notes"><title>Notes</title>
  92         <para>
  93             If an error is generated,
  94             no change is made to the contents of <parameter>data</parameter>.
  95         </para>
  96         <para>
  97             The <constant>GL_ATOMIC_COUNTER_BUFER</constant> target is available only if the GL version is 4.2 or greater.
  98         </para>
  99         <para>
 100             The <constant>GL_DISPATCH_INDIRECT_BUFFER</constant> target is available only if the GL version is 4.3 or greater.
 101         </para>
 102     </refsect1>
 103     <refsect1 id="errors"><title>Errors</title>
 104         <para>
 105             <constant>GL_INVALID_ENUM</constant> is generated if <parameter>target</parameter> is not
 106             <constant>GL_ARRAY_BUFFER</constant>, <constant>GL_ELEMENT_ARRAY_BUFFER</constant>,
 107             <constant>GL_PIXEL_PACK_BUFFER</constant>, or <constant>GL_PIXEL_UNPACK_BUFFER</constant>.
 108         </para>
 109         <para>
 110             <constant>GL_INVALID_VALUE</constant> is generated if <parameter>offset</parameter> or
 111             <parameter>size</parameter> is negative, or if together they define a region of memory
 112             that extends beyond the buffer object's allocated data store.
 113         </para>
 114         <para>
 115             <constant>GL_INVALID_OPERATION</constant> is generated if the reserved buffer object name 0 is bound to <parameter>target</parameter>.
 116         </para>
 117         <para>
 118             <constant>GL_INVALID_OPERATION</constant> is generated if the buffer object being queried is mapped.
 119         </para>
 120     </refsect1>
 121     <refsect1 id="seealso"><title>See Also</title>
 122         <para>
 123             <citerefentry><refentrytitle>glBindBuffer</refentrytitle></citerefentry>,
 124             <citerefentry><refentrytitle>glBufferData</refentrytitle></citerefentry>,
 125             <citerefentry><refentrytitle>glBufferSubData</refentrytitle></citerefentry>,
 126             <citerefentry><refentrytitle>glMapBuffer</refentrytitle></citerefentry>,
 127             <citerefentry><refentrytitle>glUnmapBuffer</refentrytitle></citerefentry>
 128         </para>
 129     </refsect1>
 130     <refsect1 id="Copyright"><title>Copyright</title>
 131         <para>
 132             Copyright <trademark class="copyright"></trademark> 2005 Addison-Wesley.
 133             This material may be distributed subject to the terms and conditions set forth in
 134             the Open Publication License, v 1.0, 8 June 1999.
 135             <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.
 136         </para>
 137     </refsect1>
 138 </refentry>