upstream-man-pages/manglsl/unpackUnorm2x16.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="unpackUnorm">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>2011</year>
   9                 <holder>Khronos Group</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>unpackUnorm</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>unpackUnorm2x16, unpackUnorm4x8, unpackSnorm4x8</refname>
  17         <refpurpose>unpack floating-point values from an unsigned integer</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>Declaration</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>vec2 <function>unpackUnorm2x16</function></funcdef>
  23                 <paramdef>uint <parameter>p</parameter></paramdef>
  24             </funcprototype>
  25             <funcprototype>
  26                 <funcdef>vec2 <function>unpackSnorm2x16</function></funcdef>
  27                 <paramdef>uint <parameter>p</parameter></paramdef>
  28             </funcprototype>
  29             <funcprototype>
  30                 <funcdef>vec4 <function>unpackUnorm4x8</function></funcdef>
  31                 <paramdef>uint <parameter>p</parameter></paramdef>
  32             </funcprototype>
  33             <funcprototype>
  34                 <funcdef>vec4 <function>unpackSnorm4x8</function></funcdef>
  35                 <paramdef>uint <parameter>p</parameter></paramdef>
  36             </funcprototype>
  37         </funcsynopsis>
  38     </refsynopsisdiv>
  39     <refsect1 id="parameters"><title>Parameters</title>
  40         <variablelist>
  41         <varlistentry>
  42             <term><parameter>p</parameter></term>
  43             <listitem>
  44                 <para>
  45                     Specifies an unsigned integer containing packed floating-point values.
  46                 </para>
  47             </listitem>
  48         </varlistentry>
  49         </variablelist>
  50     </refsect1>
  51     <refsect1 id="description"><title>Description</title>
  52         <para>
  53             <function>unpackUnorm2x16</function>, <function>unpackSnorm2x16</function>, <function>unpackUnorm4x8</function> and <function>unpackSnorm4x8</function> unpack
  54             single 32-bit unsigned integers, specified in the parameter <parameter>p</parameter> into a pair of 16-bit unsigned integers,
  55             four 8-bit unsigned integers or four 8-bit signed integers. Then, each component is converted to a normalized floating-point
  56             value to generate the returned two- or four-component vector.
  57         </para>
  58         <para>
  59             The conversion for unpacked fixed point value <emphasis>f</emphasis> to floating-point is performed as follows:
  60             <itemizedlist>
  61                 <listitem><function>packUnorm2x16</function>: <code>f / 65535.0</code></listitem>
  62                 <listitem><function>packSnorm2x16</function>: <code><citerefentry><refentrytitle>clamp</refentrytitle></citerefentry>(f / 32727.0, -1.0, 1.0)</code></listitem>
  63                 <listitem><function>packUnorm4x8</function>: <code>f / 255.0</code></listitem>
  64                 <listitem><function>packSnorm4x8</function>: <code><citerefentry><refentrytitle>clamp</refentrytitle></citerefentry>(f / 127.0, -1.0, 1.0)</code></listitem>
  65             </itemizedlist>
  66         </para>
  67         <para>
  68             The first component of the returned vector will be extracted from the least significant bits of the input;
  69             the last component will be extracted from the most significant bits.
  70         </para>
  71     </refsect1>
  72     <refsect1 id="versions"><title>Version Support</title>
  73         <informaltable frame="topbot">
  74             #VARTABLECOLS#
  75                 <thead>
  76                     #FUNCTABLEHEADER#
  77                     <row>
  78                         <entry>unpackUnorm2x16</entry>#newin41#
  79                     </row>
  80                     <row>
  81                         <entry>unpackSnorm2x16</entry>#newin42#
  82                     </row>
  83                     <row>
  84                         <entry>unpackUnorm4x8</entry>#newin41#
  85                     </row>
  86                     <row>
  87                         <entry>unpackSnorm4x8</entry>#newin41#
  88                     </row>
  89                 </thead>
  90             </tgroup>
  91         </informaltable>
  92     </refsect1>
  93     <refsect1 id="seealso"><title>See Also</title>
  94         <para>
  95             <citerefentry><refentrytitle>packUnorm2x16</refentrytitle></citerefentry>,
  96             <citerefentry><refentrytitle>packUnorm4x8</refentrytitle></citerefentry>,
  97             <citerefentry><refentrytitle>packSnorm4x8</refentrytitle></citerefentry>
  98         </para>
  99     </refsect1>
 100     <refsect1 id="Copyright"><title>Copyright</title>
 101         <para>
 102             Copyright <trademark class="copyright"></trademark> 2011 Khronos Group.
 103             This material may be distributed subject to the terms and conditions set forth in
 104             the Open Publication License, v 1.0, 8 June 1999.
 105             <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.
 106         </para>
 107     </refsect1>
 108 </refentry>