| <?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>sampler_t</title> |
| <meta name="generator" content="DocBook XSL Stylesheets V1.79.1" /> |
| <meta name="keywords" content="sampler_t" /> |
| </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="sampler_t"></a> |
| <h1> sampler_t</h1> |
| <p> |
| A type used to control how elements of an image object are read by |
| read_image{f<a xmlns="http://www.w3.org/1999/xhtml" class="citerefentry" href="imageFunctions.html"><span class="citerefentry"><span class="refentrytitle">|</span></span></a>i|ui}. |
| </p> |
| </div> |
| <div class="refsect2"> |
| <a id="synopsis"></a> |
| <h3> |
| </h3> |
| <div class="informaltable"> |
| <table class="informaltable" border="0"> |
| <colgroup> |
| <col align="left" class="col1" /> |
| </colgroup> |
| <tbody> |
| <tr> |
| <td align="left"> |
| const sampler_t <sampler name> = <value> |
| constant sampler_t <sampler name> = <value> |
| __constant sampler_t <sampler name> = <value> |
| </td> |
| </tr> |
| </tbody> |
| </table> |
| </div> |
| </div> |
| <div class="refsect1"> |
| <a id="description"></a> |
| <h2>Description</h2> |
| <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 can |
| be declared in the outermost scope of <code class="code">kernel</code> functions, or it can be a |
| constant variable of type <span class="type">sampler_t</span> declared in the program source. |
| </p> |
| <p> |
| Sampler variables in a program are declared to be of type <span class="type">sampler_t</span>. A |
| variable of <span class="type">sampler_t</span> type declared in the program source must be |
| initialized with a 32-bit unsigned integer constant, which is interpreted as a |
| bit-field specifiying the following properties: |
| </p> |
| <p> |
| </p> |
| <div class="itemizedlist"> |
| <ul class="itemizedlist" style="list-style-type: disc; "> |
| <li class="listitem"> |
| <p> Addressing Mode </p> |
| </li> |
| <li class="listitem"> |
| <p> Filter Mode </p> |
| </li> |
| <li class="listitem"> |
| <p> Normalized Coordinates </p> |
| </li> |
| </ul> |
| </div> |
| <p> |
| </p> |
| <p> |
| These properties control how elements of an image object are read by <a class="citerefentry" href="imageFunctions.html"><span class="citerefentry"><span class="refentrytitle">read_image{f|i|ui}</span></span></a>. |
| </p> |
| <p> |
| Samplers can also be declared as global constants in the program source using the |
| syntax shown at the top of this page. |
| </p> |
| <p> |
| The sampler fields are described in the table below: |
| </p> |
| <p> |
| </p> |
| <div class="informaltable"> |
| <table class="informaltable" border="1"> |
| <colgroup> |
| <col align="left" class="col1" /> |
| <col align="left" class="col2" /> |
| </colgroup> |
| <thead> |
| <tr> |
| <th align="left">Sampler State</th> |
| <th align="left">Description</th> |
| </tr> |
| </thead> |
| <tbody> |
| <tr> |
| <td align="left"> |
| <p> |
| <code class="constant"><normalized coords></code> |
| </p> |
| </td> |
| <td align="left"> |
| <p> |
| Specifies whether the <code class="varname">x</code>, <code class="varname">y</code> |
| and <code class="varname">z</code> coordinates are passed in as normalized or |
| unnormalized values. This must be a literal value and can be one of the |
| following predefined enums: |
| </p> |
| |
| <p> |
| </p><div class="literallayout"><p><code class="constant">CLK_NORMALIZED_COORDS_TRUE</code> or<br /> |
| <code class="constant">CLK_NORMALIZED_COORDS_FALSE</code>.</p></div><p> |
| </p> |
| |
| <p> |
| The samplers used with an image in multiple calls to <a class="citerefentry" href="imageFunctions.html"><span class="citerefentry"><span class="refentrytitle">read_image</span></span></a>{f|i|ui} |
| declared in a kernel must use the same value for <code class="constant"><normalized |
| coords></code>. |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td align="left"> |
| <p> |
| <code class="constant"><addressing mode></code> |
| </p> |
| </td> |
| <td align="left"> |
| <p> |
| Specifies the image addressing-mode i.e. how out-of-range image coordinates |
| are handled. This must be a literal value and can be one of the following |
| predefined enums: |
| </p> |
| |
| <p> |
| <code class="constant">CLK_ADDRESS_MIRRORED_REPEAT</code> - Flip the image |
| coordinate at every integer junction. This addressing mode can only be used |
| with normalized coordinates. If normalized coordinates are not used, |
| this addressing mode may generate image coordinates that are undefined. |
| </p> |
| |
| <p> |
| <code class="constant">CLK_ADDRESS_REPEAT</code> - out-of-range image coordinates |
| are wrapped to the valid range. This <code class="constant">address mode</code> |
| can only be used with normalized coordinates. If normalized coordinates |
| are not used, this addressing mode may generate image coordinates that |
| are undefined. |
| </p> |
| |
| <p> |
| <code class="constant">CLK_ADDRESS_CLAMP_TO_EDGE</code> - out-of-range image |
| coordinates are clamped to the extent. |
| </p> |
| |
| <p> |
| <code class="constant">CLK_ADDRESS_CLAMP</code> - out-of-range image coordinates |
| will return a border color. This is similar to the |
| <code class="constant">GL_ADDRESS_CLAMP_TO_BORDER</code> addressing mode. |
| </p> |
| |
| <p> |
| <code class="constant">CLK_ADDRESS_NONE</code> - for this addressing mode the programmer |
| guarantees that the image coordinates used to sample elements of the image |
| refer to a location inside the image; otherwise the results are undefined. |
| </p> |
| |
| <p> |
| For 1D and 2D image arrays, the addressing mode applies only to |
| the x and <span class="emphasis"><em>(x, y)</em></span> coordinates. The addressing |
| mode for the coordinate which specifies the array index is always |
| <code class="constant">CLK_ADDRESS_CLAMP_TO_EDGE</code> |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td align="left"> |
| <p> |
| <code class="constant"><filter mode></code> |
| </p> |
| </td> |
| <td align="left"> |
| <p> |
| Specifies the filtering mode to use. This must |
| be a literal value and can be one of the following |
| predefined enums: <code class="constant">CLK_FILTER_NEAREST</code> or |
| <code class="constant">CLK_FILTER_LINEAR</code>. Refer to section 8.2 for a |
| description of these filter modes. |
| </p> |
| </td> |
| </tr> |
| </tbody> |
| </table> |
| </div> |
| <p> |
| </p> |
| </div> |
| <div class="refsect1"> |
| <a id="notes"></a> |
| <h2>Notes</h2> |
| <p> |
| The sampler_t type is only |
| defined if the device supports images i.e. |
| <code class="constant">CL_DEVICE_IMAGE_SUPPORT</code> as described in table |
| 4.3 is <code class="constant">CL_TRUE</code>. |
| </p> |
| <p> |
| Note that samplers declared using the |
| <code class="code">constant</code> qualifier are not counted towards the maximum number of arguments |
| pointing to the constant address space or the maximum size of the constant address space |
| allowed per device (i.e. <code class="constant">CL_DEVICE_MAX_CONSTANT_ARGS</code> and |
| <code class="constant">CL_DEVICE_MAX_CONSTANT_BUFFER_SIZE</code> as described in table 4.3). |
| </p> |
| <p> |
| The maximum number of samplers that can be declared in a |
| kernel can be queried using the <code class="constant">CL_DEVICE_MAX_SAMPLERS</code> token in |
| <a class="citerefentry" href="clGetDeviceInfo.html"><span class="citerefentry"><span class="refentrytitle">clGetDeviceInfo</span></span></a>. |
| </p> |
| <p> |
| |
| If <code class="code"><addressing mode></code> in sampler is |
| <code class="constant">CLK_ADDRESS_CLAMP</code>, then out-of-range image coordinates return |
| the border color. The border color selected depends on the image channel order and |
| can be one of the following values: |
| </p> |
| <div class="itemizedlist"> |
| <ul class="itemizedlist" style="list-style-type: disc; "> |
| <li class="listitem" style="list-style-type: disc"> |
| <p> |
| If the image channel order is <code class="constant">CL_A</code>, |
| <code class="constant">CL_INTENSITY</code>, <code class="constant">CL_Rx</code>, |
| <code class="constant">CL_RA</code>, <code class="constant">CL_RGx</code>, |
| <code class="constant">CL_RGBx</code>, <code class="constant">CL_sRGBx</code>, <code class="constant">CL_ARGB</code>, |
| <code class="constant">CL_BGRA</code>, <code class="constant">CL_ABGR</code>, <code class="constant">CL_RGBA</code>, |
| <code class="constant">CL_sRGBA</code> or <code class="constant">CL_sBGRA</code>, the border color |
| is (0.0f, 0.0f,0.0f, 0.0f). |
| </p> |
| </li> |
| <li class="listitem" style="list-style-type: disc"> |
| <p> |
| If the image channel order is <code class="constant">CL_R</code>, |
| <code class="constant">CL_RG</code>, <code class="constant">CL_RGB</code>, or |
| <code class="constant">CL_LUMINANCE</code>, the border color is (0.0f, 0.0f, 0.0f, 1.0f) |
| </p> |
| </li> |
| <li class="listitem" style="list-style-type: disc"> |
| <p> |
| If the image channel order is <code class="constant">CL_DEPTH</code>, |
| the border value is 0.0f. |
| </p> |
| </li> |
| </ul> |
| </div> |
| <p> |
| A kernel that uses a |
| sampler with the <code class="constant">CL_ADDRESS_CLAMP</code> 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 <a class="citerefentry" href="imageFunctions.html"><span class="citerefentry"><span class="refentrytitle">read_image{f|i|ui}</span></span></a>, |
| 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 <code class="constant">CL_DEVICE_MAX_SAMPLERS</code>. Enqueuing a kernel that |
| requires more samplers than the implementation can support will result in a |
| <code class="constant">CL_OUT_OF_RESOURCES</code> error being returned. |
| </p> |
| <p> |
| The sampler type (sampler_t) can only be used as the type of a function argument or a |
| variable declared in the program scope or the outermost scope of a kernel function. The |
| behavior of a sampler variable declared in a non-outermost scope of a kernel function is |
| implementation-defined. A sampler argument or variable cannot be modified. |
| </p> |
| <p> |
| The sampler type cannot be used to declare a structure or union field, an array of |
| samplers, a pointer to a sampler, or the return type of a function. The sampler type |
| cannot be used with the <code class="code">__local</code> and |
| <code class="code">__global</code> address space qualifiers. |
| </p> |
| </div> |
| <div class="refsect2"> |
| <a id="example1"></a> |
| <h3> |
| Example |
| </h3> |
| <div class="informaltable"> |
| <table class="informaltable" border="0"> |
| <colgroup> |
| <col align="left" class="col1" /> |
| </colgroup> |
| <tbody> |
| <tr> |
| <td align="left"> |
| const sampler_t samplerA = CLK_NORMALIZED_COORDS_TRUE | |
| CLK_ADDRESS_REPEAT | |
| CLK_FILTER_NEAREST; |
| </td> |
| </tr> |
| </tbody> |
| </table> |
| </div> |
| <p> |
| samplerA specifies a sampler that uses normalized coordinates, the repeat addressing |
| mode and a nearest filter. |
| </p> |
| </div> |
| <div class="refsect1"> |
| <a id="specification"></a> |
| <h2>Specification</h2> |
| <p> |
| <img src="pdficon_small1.gif" /> |
| |
| <a href="https://www.khronos.org/registry/cl/specs/opencl-2.0-openclc.pdf#namedest=sampler_t" target="OpenCL Spec">OpenCL Specification</a> |
| </p> |
| </div> |
| <div class="refsect1"> |
| <a id="seealso"></a> |
| <h2>Also see</h2> |
| <p> |
| <a class="citerefentry" href="otherDataTypes.html"><span class="citerefentry"><span class="refentrytitle">Other Data Types</span></span></a>, |
| <a class="citerefentry" href="imageFunctions.html"><span class="citerefentry"><span class="refentrytitle">Image Read and Write Functions</span></span></a>, |
| <a class="citerefentry" href="classDiagram.html"><span class="citerefentry"><span class="refentrytitle">Cardinality Diagram</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 © 2007-2015 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> |