<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "xhtml1-transitional.dtd">
<!-- saved from url=(0013)about:internet -->
<?xml-stylesheet type="text/xsl" href="mathml.xsl"?><html xmlns="http://www.w3.org/1999/xhtml" xmlns:pref="http://www.w3.org/2002/Math/preference" xmlns:xlink="http://www.w3.org/1999/xlink" pref:renderer="mathplayer-dl">
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
    <style xmlns="" type="text/css">
    /* This style sets a margin around the entire page */
        html, body {
            margin: 10px;
        }

        p {
            font: normal 16px verdana, sans-serif;
            margin: 0;
            padding-bottom:12px;
        }

        h1 {
            font: bold 25px verdana, sans-serif;
            margin-top: 0;
            margin-bottom: 3px;
            padding-top: 0;
            padding-bottom: 0;
        }

        h2 {
            font: bold 19px verdana, sans-serif;
            margin-top: 28px;
            margin-bottom: 3px;
            padding-top: 0;
            padding-bottom: 0;
        }

        h3 {
            font: bold 19px verdana, sans-serif !important;
            margin-top: 28px;
            margin-bottom: 3px;
            padding-top: 0;
            padding-bottom: 0;
        }

        li {
            font: normal 16px verdana, sans-serif;
            margin-top: 0;
            margin-bottom: 18px;
            padding-top: 0;
            padding-bottom: 0;
        }

        .pdparam {
            font: italic 16px verdana, sans-serif;
        }

                .term {
                        font: italic 16px verdana, sans-serif;
                        font-weight: normal;
                }

                .type {
                        font: normal 16px verdana, sans-serif !important;
                }

                .parameter {
                        font-style: italic;
                        }

        a:link, a:visited {
            color: blue;
            text-decoration: none;
            font: normal 16px;
        }

        a:hover {
            background-color: #FFFF99;
            font: normal 16px;
        }

        div.funcsynopsis {
            text-align: left;
            background-color: #e6e6e6;
            font: normal 16px verdana, sans-serif;
                        padding-top: 10px;
                        padding-bottom: 10px;
        }

        div.funcsynopsis table {
            border-collapse: separate;
            font: normal 16px verdana, sans-serif;
        }

        div.funcsynopsis td {
            background-color: #e6e6e6;
            border: 0 solid #000;
            padding: 1px;
            font: normal 16px verdana, sans-serif;
        }

        div.refsect1 {
            font-family: verdana, sans-serif;
            font-size: 16px;
        }

        code.constant {
            font: normal 16px courier new, monospace !important;
        }

                span.errorname {
            font: normal 16px verdana, sans-serif !important;
        }

        code.function {
            font: bold 16px verdana, sans-serif !important;
        }

        b.fsfunc {
            font: bold 16px verdana, sans-serif !important;
        }

        code.varname {
            font: italic 16px verdana, sans-serif;
        }

        code.replaceable {
            font: italic 16px courier new, monospace;
        }

        code.funcdef {
            font: normal 16px verdana, sans-serif !important;
        }

        .citerefentry {
            font: normal 16px verdana, sans-serif !important;
        }

        .parameter {
            font-style: italic;
        }

        code.fsfunc {
            font: normal 16px verdana, sans-serif !important;
        }

        /* PARAMETER: This style controls spacing between the terms in Parameter section */
        dt {
            margin-top: 15px;
        }

        /* TABLES: These styles apply to all tables OTHER than the Synopsis and Example tables */
        div.refsect1 table {
            width: 100%;
                        margin-top: 10px;
            background-color: #FFF;
                        border-collapse: collapse;
                        border-color: #000;
            border-width: 1px;
                        font: normal 16px verdana, sans-serif;
        }

        div.refsect1 th {
                        border-collapse: collapse;
                        border-color: #000;
            border-width: 1px;
            font: bold 16px verdana, sans-serif;
        }

        div.refsect1 td {
            background-color: #FFF;
            padding: 5px;
            vertical-align: text-top;
                        border-collapse: collapse;
                        border-color: #000;
            border-width: 1px;
            font: normal 16px verdana, sans-serif;
        }

                  div.refsect1 p{
            font: normal 16px verdana, sans-serif;
            margin-top: 8px;
            margin-bottom: 8px;
            padding-top: 0;
            padding-bottom: 0;
        }


        /* EXAMPLE: These styles apply only to the Example section */
        div.refsect2 {
            font: normal 16px courier new, monospace !important;
        }

        div.refsect2 table {
            margin-top: 0;
            background-color: #e6e6e6;
            width: 100%;
            border: 0 solid #000;
            padding: 2px;
            font: normal 16px courier new, monospace !important;
        }

        div.refsect2 td {
            background-color: #e6e6e6;
            font: normal 16px courier new, monospace !important;
                        white-space:pre;
        }

        /* COPYRIGHT: This style formats the text of the copyright statement at the bottom of the page */
        div.refsect3 {
            font: normal 11px verdana, sans-serif;
            margin-top: 50px;
            margin-bottom: 20px;
            padding-top: 0;
            padding-bottom: 0;
        }

</style>
    <title>write_imageh</title>
    <meta name="generator" content="DocBook XSL Stylesheets V1.78.1" />
    <meta name="keywords" content="write_imageh" />
  </head>
  <body>
    <div class="refentry">
      <a id="id-1"></a>
      <div class="titlepage"></div>
      <div xmlns="" class="refnamediv">
        <a xmlns="http://www.w3.org/1999/xhtml" id="write_image"></a>
        <h1>write_imageh (2D)</h1>
        <p>
            Write <code xmlns="http://www.w3.org/1999/xhtml" class="varname">color</code> value to location in the 2D image object.
        </p>
      </div>
      <div class="refsynopsisdiv">
        <h2></h2>
        <div class="funcsynopsis">
          <table xmlns="" border="0" summary="Function synopsis" cellspacing="0" cellpadding="0">
            <tr valign="bottom">
              <td>
                <code xmlns="http://www.w3.org/1999/xhtml" class="funcdef">
                    <a class="link" href="scalarDataTypes.html" target="_top">void</a>
                    <strong class="fsfunc">                   
                        write_imageh
                    </strong>
                (</code>
                <td><a xmlns="http://www.w3.org/1999/xhtml" class="link" href="otherDataTypes.html" target="_top">image2d_t</a> <var xmlns="http://www.w3.org/1999/xhtml" class="pdparam">image</var>, </td>
              </td>
            </tr>
            <tr valign="top">
              <td> </td>
              <td><a xmlns="http://www.w3.org/1999/xhtml" class="link" href="vectorDataTypes.html" target="_top">int2</a> <var xmlns="http://www.w3.org/1999/xhtml" class="pdparam">coord</var>, </td>
            </tr>
            <tr valign="top">
              <td> </td>
              <td><a xmlns="http://www.w3.org/1999/xhtml" class="link" href="vectorDataTypes.html" target="_top">half4</a> <var xmlns="http://www.w3.org/1999/xhtml" class="pdparam">color</var><code>)</code></td>
            </tr>
          </table>
        </div>
      </div>
      <div class="refsect1">
        <a id="description"></a>
        <h2>Description</h2>
        <p>
        Write <code class="varname">color</code> value to location specified by coordinate <span class="emphasis"><em>(x, y)</em></span> in the 2D image object specified by <code class="varname">image</code>. Appropriate data format conversion to the specified image format is done before writing the color value. <span class="emphasis"><em>x</em></span> and <span class="emphasis"><em>y</em></span> are considered to be unnormalized coordinates and must be in the range 0... image width - 1, and 0... image height - 1.
        </p>
        <p>      
<code class="function">write_imageh</code> can only be used with image objects created with <code class="varname">image_channel_data_type</code> set to one of the pre-defined packed formats or set to CL_SNORM_INT8, CL_UNORM_INT8, CL_SNORM_INT16, CL_UNORM_INT16, or CL_HALF_FLOAT. Appropriate data format conversion will be done to convert channel data from a half floating-point value to actual data format in which the channels are stored.
        </p>
        <p>  
The behavior of <code class="function">write_imageh</code> for image objects created with <code class="varname">image_channel_data_type</code> values not specified in the description above or with <span class="emphasis"><em>(x, y)</em></span> coordinate values that are not in the range (0... image width - 1, 0... image height - 1), respectively, is undefined.
        </p>
      </div>
      <div class="refsect1">
        <a id="notes"></a>
        <h2>Notes</h2>
        <p>  
        The built-in functions defined in this section can only be used with image memory objects
created with <a class="citerefentry" href="clCreateImage2D.html"><span class="citerefentry"><span class="refentrytitle">clCreateImage2D</span></span></a>, or <a class="citerefentry" href="clCreateImage3D.html"><span class="citerefentry"><span class="refentrytitle">clCreateImage3D</span></span></a>. An image memory object can be
accessed by specific function calls that read from and/or write to specific locations in the image.
        </p>
        <p>
Image memory objects that are being read by a kernel should be declared with the
<a class="citerefentry" href="accessQualifiers.html"><span class="citerefentry"><span class="refentrytitle">__read_only</span></span></a> qualifier. <a class="citerefentry" href="write_image.html"><span class="citerefentry"><span class="refentrytitle">write_image</span></span></a> calls to image memory objects declared with the
<a class="citerefentry" href="accessQualifiers.html"><span class="citerefentry"><span class="refentrytitle">__read_only</span></span></a> qualifier will generate a compilation error. Image memory objects that are
being written to by a kernel should be declared with the <a class="citerefentry" href="accessQualifiers.html"><span class="citerefentry"><span class="refentrytitle">__write_only</span></span></a> qualifier.
<a class="citerefentry" href="read_image.html"><span class="citerefentry"><span class="refentrytitle">read_image</span></span></a> calls to image memory objects declared with the <a class="citerefentry" href="accessQualifiers.html"><span class="citerefentry"><span class="refentrytitle">__write_only</span></span></a> qualifier will
generate a compilation error. <a class="citerefentry" href="read_image.html"><span class="citerefentry"><span class="refentrytitle">read_image</span></span></a> 
and <a class="citerefentry" href="write_image.html"><span class="citerefentry"><span class="refentrytitle">write_image</span></span></a> calls to the same image memory
object in a kernel are not supported.
        </p>
        <p>
The <a class="citerefentry" href="read_image.html"><span class="citerefentry"><span class="refentrytitle">read_image</span></span></a> calls returns a four component floating-point, integer or unsigned integer color
value. The color values returned by <a class="citerefentry" href="read_image.html"><span class="citerefentry"><span class="refentrytitle">read_image</span></span></a> are identified as <em class="replaceable"><code>x, y, z, w</code></em> where <em class="replaceable"><code>x</code></em> refers to
the red component, <em class="replaceable"><code>y</code></em> refers to the green component, <em class="replaceable"><code>z</code></em> refers to the blue component and <em class="replaceable"><code>w</code></em> refers to the alpha component.
        </p>
        <p>
        The image read functions take a sampler argument. The sampler can be passed as an argument
to the kernel using <a class="citerefentry" href="clSetKernelArg.html"><span class="citerefentry"><span class="refentrytitle">clSetKernelArg</span></span></a>, or it can be a constant variable of type <a class="citerefentry" href="sampler_t.html"><span class="citerefentry"><span class="refentrytitle">sampler_t</span></span></a> declared in the program source.
        </p>
        <p>
            A kernel that uses a sampler with the CL_ADDRESS_CLAMP addressing mode with
multiple images may result in additional samplers being used internally by an implementation. If
the same sampler is used with multiple images called via <code class="function">read_image{f | i | ui}</code>, then it is
possible that an implementation may need to allocate an additional sampler to handle the
different border color values that may be needed depending on the image formats being used.
These implementation allocated samplers will count against the maximum sampler values
supported by the device and given by CL_DEVICE_MAX_SAMPLERS. Enqueuing a kernel that
requires more samplers than the implementation can support will result in a
CL_OUT_OF_RESOURCES error being returned.
        </p>
      </div>
      <div class="refsect1">
        <a id="specification"></a>
        <h2>Specification</h2>
        <p>
            <img src="pdficon_small1.gif" />
                                                 
            <a href="http://www.khronos.org/registry/cl/specs/opencl-1.1.pdf#page=234" target="OpenCL Spec">OpenCL Specification</a>
        </p>
      </div>
      <div class="refsect1">
        <a id="seealso"></a>
        <h2>Also see</h2>
        <p>
            <a class="citerefentry" href="imageFunctions.html"><span class="citerefentry"><span class="refentrytitle">Image Functions</span></span></a> 
        </p>
      </div>
      <div xmlns="" class="refsect3" lang="en" xml:lang="en"><a xmlns="http://www.w3.org/1999/xhtml" id="Copyright"></a><h4 xmlns="http://www.w3.org/1999/xhtml"></h4><img xmlns="http://www.w3.org/1999/xhtml" src="KhronosLogo.jpg" /><p xmlns="http://www.w3.org/1999/xhtml"></p>Copyright © 2007-2010 The Khronos Group Inc.
Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and/or associated documentation files (the
"Materials"), to deal in the Materials without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Materials, and to
permit persons to whom the Materials are furnished to do so, subject to
the condition that this copyright notice and permission notice shall be included
in all copies or substantial portions of the Materials.
</div>
    </div>
  </body>
</html>