upstream-doc/man3/glCopyBufferSubData.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="glCopyBufferSubData">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>2010</year>
   9                 <holder>Khronos Group</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>glCopyBufferSubData</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>glCopyBufferSubData</refname>
  17         <refpurpose>copy part of the data store of a buffer object to the data store of another buffer object</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>C Specification</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>void <function>glCopyBufferSubData</function></funcdef>
  23                 <paramdef>GLenum <parameter>readtarget</parameter></paramdef>
  24                 <paramdef>GLenum <parameter>writetarget</parameter></paramdef>
  25                 <paramdef>GLintptr <parameter>readoffset</parameter></paramdef>
  26                 <paramdef>GLintptr <parameter>writeoffset</parameter></paramdef>
  27                 <paramdef>GLsizeiptr <parameter>size</parameter></paramdef>
  28             </funcprototype>
  29         </funcsynopsis>
  30     </refsynopsisdiv>
  31     <!-- eqn: ignoring delim $$ -->
  32     <refsect1 id="parameters"><title>Parameters</title>
  33         <variablelist>
  34         <varlistentry>
  35             <term><parameter>readtarget</parameter></term>
  36             <listitem>
  37                 <para>
  38                     Specifies the target from whose data store data should be read.
  39                 </para>
  40             </listitem>
  41         </varlistentry>
  42         <varlistentry>
  43             <term><parameter>writetarget</parameter></term>
  44             <listitem>
  45                 <para>
  46                     Specifies the target to whose data store data should be written.
  47                 </para>
  48             </listitem>
  49         </varlistentry>
  50         <varlistentry>
  51             <term><parameter>readoffset</parameter></term>
  52             <listitem>
  53                 <para>
  54                     Specifies the offset, in basic machine units, within the data store of <parameter>readtarget</parameter> from which data should be read.
  55                 </para>
  56             </listitem>
  57         </varlistentry>
  58         <varlistentry>
  59             <term><parameter>writeoffset</parameter></term>
  60             <listitem>
  61                 <para>
  62                     Specifies the offset, in basic machine units, within the data store of <parameter>writetarget</parameter> to which data should be written.
  63                 </para>
  64             </listitem>
  65         </varlistentry>
  66         <varlistentry>
  67             <term><parameter>size</parameter></term>
  68             <listitem>
  69                 <para>
  70                     Specifies the size, in basic machine units, of the data to be copied from <parameter>readtarget</parameter> to <parameter>writetarget</parameter>.
  71                 </para>
  72             </listitem>
  73         </varlistentry>
  74         </variablelist>
  75     </refsect1>
  76     <refsect1 id="description"><title>Description</title>
  77         <para>
  78             <function>glCopyBufferSubData</function> copies part of the data store attached to <parameter>readtarget</parameter> to the
  79             data store attached to <parameter>writetarget</parameter>. The number of basic machine units indicated by <parameter>size</parameter>
  80             is copied from the source, at offset <parameter>readoffset</parameter> to the destination at <parameter>writeoffset</parameter>,
  81             also in basic machine units.
  82         </para>
  83         <para>
  84             <parameter>readtarget</parameter> and <parameter>writetarget</parameter> must be <constant>GL_ARRAY_BUFFER</constant>,
  85             <constant>GL_COPY_READ_BUFFER</constant>, <constant>GL_COPY_WRITE_BUFFER</constant>, <constant>GL_ELEMENT_ARRAY_BUFFER</constant>,
  86             <constant>GL_PIXEL_PACK_BUFFER</constant>, <constant>GL_PIXEL_UNPACK_BUFFER</constant>, <constant>GL_TEXTURE_BUFFER</constant>,
  87             <constant>GL_TRANSFORM_FEEDBACK_BUFFER</constant> or <constant>GL_UNIFORM_BUFFER</constant>. Any of these targets may be used,
  88             although the targets <constant>GL_COPY_READ_BUFFER</constant> and <constant>GL_COPY_WRITE_BUFFER</constant> are provided
  89             specifically to allow copies between buffers without disturbing other GL state.
  90         </para>
  91         <para>
  92             <parameter>readoffset</parameter>, <parameter>writeoffset</parameter> and <parameter>size</parameter> must all be greater than or equal to
  93             zero. Furthermore, <parameter>readoffset</parameter> + <parameter>size</parameter> must not exceeed the size of the buffer
  94             object bound to <parameter>readtarget</parameter>, and <parameter>readoffset</parameter> + <parameter>size</parameter> must not exceeed the
  95             size of the buffer bound to <parameter>writetarget</parameter>. If the same buffer object is bound to both <parameter>readtarget</parameter>
  96             and <parameter>writetarget</parameter>, then the ranges specified by <parameter>readoffset</parameter>, <parameter>writeoffset</parameter>
  97             and <parameter>size</parameter> must not overlap.
  98         </para>
  99     </refsect1>
 100     <refsect1 id="notes"><title>Notes</title>
 101         <para>
 102            <function>glCopyBufferSubData</function> is available only if the GL version is 3.1 or greater.
 103         </para>
 104     </refsect1>
 105     <refsect1 id="errors"><title>Errors</title>
 106         <para>
 107             <constant>GL_INVALID_VALUE</constant> is generated if any of <parameter>readoffset</parameter>, <parameter>writeoffset</parameter>
 108             or <parameter>size</parameter> is negative, if <parameter>readoffset</parameter> + <parameter>size</parameter> exceeds the
 109             size of the buffer object bound to <parameter>readtarget</parameter> or if <parameter>writeoffset</parameter> + <parameter>size</parameter>
 110             exceeds the size of the buffer object bound to <parameter>writetarget</parameter>.
 111         </para>
 112         <para>
 113             <constant>GL_INVALID_VALUE</constant> is generated if the same buffer object is bound to both <parameter>readtarget</parameter>
 114             and <parameter>writetarget</parameter> and the ranges [<parameter>readoffset</parameter>, <parameter>readoffset</parameter> +
 115             <parameter>size</parameter>) and [<parameter>writeoffset</parameter>, <parameter>writeoffset</parameter> + <parameter>size</parameter>)
 116             overlap.
 117         </para>
 118         <para>
 119             <constant>GL_INVALID_OPERATION</constant> is generated if zero is bound to <parameter>readtarget</parameter> or <parameter>writetarget</parameter>.
 120         </para>
 121         <para>
 122             <constant>GL_INVALID_OPERATION</constant> is generated if the buffer object bound to either <parameter>readtarget</parameter> or <parameter>writetarget</parameter>
 123             is mapped.
 124         </para>
 125     </refsect1>
 126     <refsect1 id="seealso"><title>See Also</title>
 127         <para>
 128             <citerefentry><refentrytitle>glGenBuffers</refentrytitle></citerefentry>,
 129             <citerefentry><refentrytitle>glBindBuffer</refentrytitle></citerefentry>,
 130             <citerefentry><refentrytitle>glBufferData</refentrytitle></citerefentry>,
 131             <citerefentry><refentrytitle>glBufferSubData</refentrytitle></citerefentry>,
 132             <citerefentry><refentrytitle>glGetBufferSubData</refentrytitle></citerefentry>
 133         </para>
 134     </refsect1>
 135     <refsect1 id="Copyright"><title>Copyright</title>
 136         <para>
 137             Copyright <trademark class="copyright"></trademark> 2010 Khronos Group.
 138             This material may be distributed subject to the terms and conditions set forth in
 139             the Open Publication License, v 1.0, 8 June 1999.
 140             <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.
 141         </para>
 142     </refsect1>
 143 </refentry>