upstream-man-pages/manglsl/packUnorm2x16.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="packUnorm">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>2011</year>
   9                 <holder>Khronos Group</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>packUnorm</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>packUnorm</refname>
  17         <refpurpose>pack floating-point values into an unsigned integer</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>Declaration</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>uint <function>packUnorm2x16</function></funcdef>
  23                 <paramdef>vec2 <parameter>v</parameter></paramdef>
  24             </funcprototype>
  25             <funcprototype>
  26                 <funcdef>uint <function>packSnorm2x16</function></funcdef>
  27                 <paramdef>vec2 <parameter>v</parameter></paramdef>
  28             </funcprototype>
  29             <funcprototype>
  30                 <funcdef>uint <function>packUnorm4x8</function></funcdef>
  31                 <paramdef>vec4 <parameter>v</parameter></paramdef>
  32             </funcprototype>
  33             <funcprototype>
  34                 <funcdef>uint <function>packSnorm4x8</function></funcdef>
  35                 <paramdef>vec4 <parameter>v</parameter></paramdef>
  36             </funcprototype>
  37         </funcsynopsis>
  38     </refsynopsisdiv>
  39     <refsect1 id="parameters"><title>Parameters</title>
  40         <variablelist>
  41         <varlistentry>
  42             <term><parameter>v</parameter></term>
  43             <listitem>
  44                 <para>
  45                     Specifies a vector of values to be packed into an unsigned integer.
  46                 </para>
  47             </listitem>
  48         </varlistentry>
  49         </variablelist>
  50     </refsect1>
  51     <refsect1 id="description"><title>Description</title>
  52         <para>
  53             <function>packUnorm2x16</function>, <function>packSnorm2x16</function>, <function>packUnorm4x8</function> and <function>packSnorm4x8</function> convert
  54             each component of the normalized floating-ponit value <parameter>v</parameter> into 8- or 16-bit integer
  55             values and then packs the results into a 32-bit unsigned intgeter.
  56         </para>
  57         <para>
  58             The conversion for component <parameter>c</parameter> of <parameter>v</parameter> to fixed-point is
  59             performed as follows:
  60             <itemizedlist>
  61                 <listitem><function>packUnorm2x16</function>: <code><citerefentry><refentrytitle>round</refentrytitle></citerefentry>(<citerefentry><refentrytitle>clamp</refentrytitle></citerefentry>(<parameter>c</parameter>, 0.0, 1.0) * 65535.0)</code></listitem>
  62                 <listitem><function>packSnorm2x16</function>: <code><citerefentry><refentrytitle>round</refentrytitle></citerefentry>(<citerefentry><refentrytitle>clamp</refentrytitle></citerefentry>(<parameter>c</parameter>, -1.0, 1.0) * 32767.0)</code></listitem>
  63                 <listitem><function>packUnorm4x8</function>: <code><citerefentry><refentrytitle>round</refentrytitle></citerefentry>(<citerefentry><refentrytitle>clamp</refentrytitle></citerefentry>(<parameter>c</parameter>, 0.0, 1.0) * 255.0)</code></listitem>
  64                 <listitem><function>packSnorm4x8</function>: <code><citerefentry><refentrytitle>round</refentrytitle></citerefentry>(<citerefentry><refentrytitle>clamp</refentrytitle></citerefentry>(<parameter>c</parameter>, -1.0, 1.0) * 127.0)</code></listitem>
  65             </itemizedlist>
  66         </para>
  67         <para>
  68             The first component of the vector will be written to the least significant bits of the output;
  69             the last component will be written to 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>packUnorm2x16</entry>#newin41#
  79                     </row>
  80                     <row>
  81                         <entry>packSnorm2x16</entry>#newin42#
  82                     </row>
  83                     <row>
  84                         <entry>packUnorm4x8</entry>#newin41#
  85                     </row>
  86                     <row>
  87                         <entry>packSnorm4x8</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>unpackUnorm2x16</refentrytitle></citerefentry>,
  96             <citerefentry><refentrytitle>unpackSnorm2x16</refentrytitle></citerefentry>,
  97             <citerefentry><refentrytitle>unpackUnorm4x8</refentrytitle></citerefentry>,
  98             <citerefentry><refentrytitle>unpackSnorm4x8</refentrytitle></citerefentry>
  99         </para>
 100     </refsect1>
 101     <refsect1 id="Copyright"><title>Copyright</title>
 102         <para>
 103             Copyright <trademark class="copyright"></trademark> 2011 Khronos Group.
 104             This material may be distributed subject to the terms and conditions set forth in
 105             the Open Publication License, v 1.0, 8 June 1999.
 106             <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.
 107         </para>
 108     </refsect1>
 109 </refentry>