sdk/1.2/docs/man/xhtml/cl_khr_gl_sharing.html - external/github.com/KhronosGroup/OpenCL-Registry - Git at Google

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 </style>
     <title>cl_khr_gl_sharing</title>
     <meta name="generator" content="DocBook XSL Stylesheets V1.78.1" />
     <meta name="keywords" content="cl_khr_gl_sharing" />
   </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="cl_khr_gl_sharing"></a>
         <h1>cl_khr_gl_sharing</h1>
         <p>
 Allow applications to use OpenGL buffer, texture and renderbuffer objects as OpenCL memory objects.
         </p>
       </div>
       <div class="refsect2">
         <a id="synopsis"></a>
         <h3>
         </h3>
         <div class="informaltable">
           <table border="0">
             <colgroup>
               <col align="left" class="col1" />
             </colgroup>
             <tbody>
               <tr>
                 <td align="left">
 cl_khr_gl_sharing
                         </td>
               </tr>
             </tbody>
           </table>
         </div>
       </div>
       <div class="refsect1">
         <a id="description"></a>
         <h2>Description</h2>
         <p>
            This is a Kronos-approved extension
           name. If this extension is supported, "cl_khr_gl_sharing" will
           be returned for <code class="constant">CL_DEVICE_EXTENSIONS</code> using
           <a class="citerefentry" href="clGetDeviceInfo.html"><span class="citerefentry"><span class="refentrytitle">clGetDeviceInfo</span></span></a>.
         </p>
         <p>
            The OpenCL specification in section 9.7 defines how to
           share data with texture and buffer objects in a parallel OpenGL implementation,
           but does not define how the association between an OpenCL context and an OpenGL
           context or share group is established. This extension defines optional attributes
           to OpenCL context creation routines which associate a GL context or share group
           object with a newly created OpenCL context. If this extension is supported by an
           implementation, the string <code class="function">cl_khr_gl_sharing</code> will be present in the
           <code class="constant">CL_PLATFORM_EXTENSIONS</code> or <code class="constant">CL_DEVICE_EXTENSIONS</code>
           string described in the table of allowed values for <code class="varname">param_name</code>
           for <a class="citerefentry" href="clGetDeviceInfo.html"><span class="citerefentry"><span class="refentrytitle">clGetDeviceInfo</span></span></a>
         </p>
         <p>
            An OpenGL implementation supporting buffer objects and
           sharing of texture and buffer object images with OpenCL is required by this extension.
         </p>
         <p>
            This section discusses OpenCL functions that allow applications
           to use OpenGL buffer, texture, and renderbuffer objects as OpenCL memory objects. This
           allows efficient sharing of data between OpenCL and OpenGL. The OpenCL API may be used
           to execute kernels that read and/or write memory objects that are also OpenGL objects.
         </p>
         <p>
            An OpenCL image object may be created from an OpenGL texture or
           renderbuffer object. An OpenCL buffer object may be created from an OpenGL buffer object.
         </p>
         <p>
            OpenCL memory objects may be created from OpenGL objects
           if and only if the OpenCL context has been created from an OpenGL share group
           object or context. OpenGL share groups and contexts are created using platform
           specific APIs such as EGL, CGL, WGL, and GLX. On MacOS X, an OpenCL context may
           be created from an OpenGL share group object using the OpenCL platform extension
           cl_apple_gl_sharing. On other platforms including Microsoft Windows, Linux/Unix and
           others, an OpenCL context may be created from an OpenGL context using the Khronos
           platform extension <code class="function">cl_khr_gl_sharing</code>. Refer to the platform
           documentation for your OpenCL implementation, or visit the Khronos Registry at
           http://www.khronos.org/registry/cl/ for more information.
         </p>
         <p>
            Any supported OpenGL object defined within the GL share
           group object, or the share group associated with the GL context from which the CL
           context is created, may be shared, with the exception of the default OpenGL objects
           (i.e. objects named zero), which may not be shared.
         </p>
         <p>

     </p>
         <p>
        The table below (Table 9.4) describes
       the list of GL texture internal formats and the corresponding CL image formats. If a GL
       texture object with an internal format from the table below is successfully created by
       OpenGL, then there is guaranteed to be a mapping to one of the corresponding CL image
       format(s) in that table. Texture objects created with other OpenGL internal formats may
       (but are not guaranteed to) have a mapping to a CL image format; if such mappings exist,
       they are guaranteed to preserve all color components, data types, and at least the number
       of bits/component actually allocated by OpenGL for that format.
     </p>
         <p>

     </p>
         <div class="informaltable">
           <table border="1">
             <colgroup>
               <col align="center" class="col1" />
               <col align="center" class="col2" />
             </colgroup>
             <thead>
               <tr>
                 <th align="center">GL internal format</th>
                 <th align="center">CL image format (channel order, channel data type)</th>
               </tr>
             </thead>
             <tbody>
               <tr>
                 <td align="center">
                   <code class="constant">GL_RGBA8</code>
                 </td>
                 <td align="center">
                   <code class="constant">CL_RGBA, CL_UNORM_INT8 or CL_BGRA, CL_UNORM_INT8</code>
                 </td>
               </tr>
               <tr>
                 <td align="center"><code class="constant">GL_RGBA</code>, <code class="constant">GL_UNSIGNED_INT_8_8_8_8_REV</code></td>
                 <td align="center">
                   <code class="constant">CL_RGBA, CL_UNORM_INT8</code>
                 </td>
               </tr>
               <tr>
                 <td align="center"><code class="constant">GL_BGRA</code>, <code class="constant">GL_UNSIGNED_INT_8_8_8_8_REV</code></td>
                 <td align="center">
                   <code class="constant">CL_BGRA, CL_UNORM_INT8</code>
                 </td>
               </tr>
               <tr>
                 <td align="center">
                   <code class="constant">GL_RGBA16</code>
                 </td>
                 <td align="center">
                   <code class="constant">CL_RGBA, CL_UNORM_INT16</code>
                 </td>
               </tr>
               <tr>
                 <td align="center">
                   <code class="constant">GL_RGBA8I, GL_RGBA8I_EXT</code>
                 </td>
                 <td align="center">
                   <code class="constant">CL_RGBA, CL_SIGNED_INT8</code>
                 </td>
               </tr>
               <tr>
                 <td align="center">
                   <code class="constant">GL_RGBA16I, GL_RGBA16I_EXT</code>
                 </td>
                 <td align="center">
                   <code class="constant">CL_RGBA, CL_SIGNED_INT16</code>
                 </td>
               </tr>
               <tr>
                 <td align="center">
                   <code class="constant">GL_RGBA32I, GL_RGBA32I_EXT</code>
                 </td>
                 <td align="center">
                   <code class="constant">CL_RGBA, CL_SIGNED_INT32</code>
                 </td>
               </tr>
               <tr>
                 <td align="center">
                   <code class="constant">GL_RGBA8UI, GL_RGBA8UI_EXT</code>
                 </td>
                 <td align="center">
                   <code class="constant">CL_RGBA, CL_UNSIGNED_INT8</code>
                 </td>
               </tr>
               <tr>
                 <td align="center">
                   <code class="constant">GL_RGBA16UI, GL_RGBA16UI_EXT</code>
                 </td>
                 <td align="center">
                   <code class="constant">CL_RGBA, CL_UNSIGNED_INT16</code>
                 </td>
               </tr>
               <tr>
                 <td align="center">
                   <code class="constant">GL_RGBA32UI, GL_RGBA32UI_EXT</code>
                 </td>
                 <td align="center">
                   <code class="constant">CL_RGBA, CL_UNSIGNED_INT32</code>
                 </td>
               </tr>
               <tr>
                 <td align="center">
                   <code class="constant">GL_RGBA16F, GL_RGBA16F_ARB</code>
                 </td>
                 <td align="center">
                   <code class="constant">CL_RGBA, CL_HALF_FLOAT</code>
                 </td>
               </tr>
               <tr>
                 <td align="center">
                   <code class="constant">GL_RGBA32F, GL_RGBA32F_ARB</code>
                 </td>
                 <td align="center">
                   <code class="constant">CL_RGBA, CL_FLOAT</code>
                 </td>
               </tr>
             </tbody>
           </table>
         </div>
         <p>


     </p>
         <p>
        In order to ensure data integrity, the application is responsible
       for synchronizing access to shared CL/GL objects by their respective APIs.  Failure to
       provide such synchronization may result in race conditions and other undefined behavior
       including non-portability between implementations.
     </p>
         <p>

     </p>
         <p>
        Prior to calling <code class="function">clEnqueueAcquireGLObjects</code>,
       the application must ensure that any pending GL operations which access the objects
       specified in <code class="varname">mem_objects</code>  have completed.  This may be accomplished
       portably by issuing and waiting for completion of a <code class="function">glFinish</code>
       command on all GL contexts with pending references to these objects.  Implementations
       may offer more efficient synchronization methods; for example on some platforms calling
       <code class="function">glFlush</code> may be sufficient, or synchronization may be implicit within
       a thread, or there may be vendor-specific extensions that enable placing a fence in the
       GL command stream and waiting for completion of that fence in the CL command queue. Note
       that no synchronization methods other than <code class="function">glFinish</code> are portable
       between OpenGL implementations at this time.
     </p>
         <p>

     </p>
         <p>
        Similarly, after calling
       <code class="function">clEnqueueReleaseGLObjects</code>, the application is responsible
       for ensuring that any pending OpenCL operations which access the objects specified
       in <code class="varname">mem_objects</code> have completed prior to executing subsequent GL
       commands which reference these objects. This may be accomplished portably by calling
       <a class="citerefentry" href="clWaitForEvents.html"><span class="citerefentry"><span class="refentrytitle">clWaitForEvents</span></span></a> with the
       event object returned by <code class="function">clEnqueueReleaseGLObjects</code>, or by calling
       <a class="citerefentry" href="clFinish.html"><span class="citerefentry"><span class="refentrytitle">clFinish</span></span></a>.  As above, some
       implementations may offer more efficient methods.
     </p>
         <p>

     </p>
         <p>
        The application is responsible for maintaining the proper order
       of operations if the CL and GL contexts are in separate threads.
     </p>
         <p>

     </p>
         <p>
        If a GL context is bound to a thread other than the one in which
       <code class="function">clEnqueueReleaseGLObjects</code> is called, changes to any of the objects in
       <code class="varname">mem_objects</code> may not be visible to that context without additional steps
       being taken by the application. For an OpenGL 3.1 (or later) context, the requirements
       are described in Appendix D ("Shared Objects and Multiple Contexts") of the OpenGL 3.1
       Specification. For prior versions of OpenGL, the requirements are implementation-dependent.
     </p>
         <p>

     </p>
         <p>
        Attempting to access the data store of an OpenGL object after
       it has been acquired by OpenCL and before it has been released will result in undefined
       behavior.  Similarly, attempting to access a shared CL/GL object from OpenCL before it
       has been acquired by the OpenCL command queue, or after it has been released, will result
       in undefined behavior.
     </p>
         <p>

     </p>
         <p>
        If the
       <a class="citerefentry" href="cl_khr_gl_event.html"><span class="citerefentry"><span class="refentrytitle">cl_khr_gl_event</span></span></a> extension
       is supported, then the OpenCL implementation will ensure that any such pending OpenGL
       operations are complete for an OpenGL context bound to the same thread as the OpenCL
       context. This is referred to as implicit synchronization.
     </p>
         <p>


     </p>
         <h4><a id="id-1.5.9.10"></a>Lifetime of Shared Objects</h4>
         <p>

     </p>
         <p>
        An OpenCL memory object created from an OpenGL object
       (hereinafter refered to as a “shared CL/GL object”) remains valid as long as the
       corresponding GL object has not been deleted. If the GL object is deleted through the GL
       API (e.g. <code class="function">glDeleteBuffers</code>, <code class="function">glDeleteTextures</code>,
       or <code class="function">glDeleteRenderbuffers</code>), subsequent use of the CL buffer or image
       object will result in undefined behavior, including but not limited to possible CL errors
       and data corruption, but may not result in program termination.
     </p>
         <p>

     </p>
         <p>
        The CL context and corresponding command-queues are dependent
       on the existence of the GL share group object, or the share group associated with the
       GL context from which the CL context is created. If the GL share group object or all GL
       contexts in the share group are destroyed, any use of the CL context or command-queue(s)
       will result in undefined behavior, which may include program termination. Applications
       should destroy the CL command-queue(s) and CL context before destroying the corresponding
       GL share group or contexts.
     </p>
         <p>


         </p>
         <h4><a id="id-1.5.10"></a>OpenCL Functions That Allow Sharing</h4>
         <p>
             Click an item in the table for details about that function.
         </p>
       </div>
       <div class="refsect1">
         <a id="springboard"></a>
         <h2></h2>
         <div class="informaltable">
           <table border="1">
             <colgroup>
               <col align="left" class="col1" />
               <col align="left" class="col2" />
             </colgroup>
             <tbody>
               <tr>
                 <td align="left">
                   <a class="citerefentry" href="clGetGLContextInfoKHR.html">
                     <span class="citerefentry">
                       <span class="refentrytitle">clGetGLContextInfoKHR</span>
                     </span>
                   </a>
                 </td>
                 <td align="left">Query the device.</td>
               </tr>
               <tr>
                 <td align="left">
                   <a class="citerefentry" href="clCreateFromGLBuffer.html">
                     <span class="citerefentry">
                       <span class="refentrytitle">clCreateFromGLBuffer</span>
                     </span>
                   </a>
                 </td>
                 <td align="left">Creates an OpenCL buffer object from an OpenGL buffer object.</td>
               </tr>
               <tr>
                 <td align="left">
                   <a class="citerefentry" href="clCreateFromGLTexture.html">
                     <span class="citerefentry">
                       <span class="refentrytitle">clCreateFromGLTexture</span>
                     </span>
                   </a>
                 </td>
                 <td align="left">Creates an OpenCL image object, image array object, or image buffer object from an OpenGL
                      texture object, texture array object, texture buffer object, or a single face of an
                      OpenGL cubemap texture object.</td>
               </tr>
               <tr>
                 <td align="left">
                   <a class="citerefentry" href="clCreateFromGLRenderbuffer.html">
                     <span class="citerefentry">
                       <span class="refentrytitle">clCreateFromGLRenderbuffer</span>
                     </span>
                   </a>
                 </td>
                 <td align="left">Creates an OpenCL 2D image object from an OpenGL renderbuffer object.</td>
               </tr>
               <tr>
                 <td align="left">
                   <a class="citerefentry" href="clGetGLObjectInfo.html">
                     <span class="citerefentry">
                       <span class="refentrytitle">clGetGLObjectInfo</span>
                     </span>
                   </a>
                 </td>
                 <td align="left">Query an OpenGL memory object used to create an OpenCL memory object.</td>
               </tr>
               <tr>
                 <td align="left">
                   <a class="citerefentry" href="clGetGLTextureInfo.html">
                     <span class="citerefentry">
                       <span class="refentrytitle">clGetGLTextureInfo</span>
                     </span>
                   </a>
                 </td>
                 <td align="left">Get additional information about the GL texture object associated with a memory object.</td>
               </tr>
               <tr>
                 <td align="left">
                   <a class="citerefentry" href="clEnqueueAcquireGLObjects.html">
                     <span class="citerefentry">
                       <span class="refentrytitle">clEnqueueAcquireGLObjects</span>
                     </span>
                   </a>
                 </td>
                 <td align="left">Acquire OpenCL memory objects that have been created from OpenGL objects.</td>
               </tr>
               <tr>
                 <td align="left">
                   <a class="citerefentry" href="clEnqueueReleaseGLObjects.html">
                     <span class="citerefentry">
                       <span class="refentrytitle">clEnqueueReleaseGLObjects</span>
                     </span>
                   </a>
                 </td>
                 <td align="left">Release OpenCL memory objects that have been created from OpenGL objects.</td>
               </tr>
             </tbody>
           </table>
         </div>
       </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-1.2-extensions.pdf#page=39" target="OpenCL Spec">OpenCL Specification</a>
         </p>
       </div>
       <div class="refsect1">
         <a id="seealso"></a>
         <h2>Also see</h2>
         <p>
             <a class="citerefentry" href="EXTENSION.html"><span class="citerefentry"><span class="refentrytitle">EXTENSION</span></span></a>,
             <a class="citerefentry" href="clGetGLContextInfoKHR.html"><span class="citerefentry"><span class="refentrytitle">clGetGLContextInfoKHR</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 © 2007-2011 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
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	</style>
	<title>cl_khr_gl_sharing</title>
	<meta name="generator" content="DocBook XSL Stylesheets V1.78.1" />
	<meta name="keywords" content="cl_khr_gl_sharing" />
	</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="cl_khr_gl_sharing"></a>
	<h1>cl_khr_gl_sharing</h1>
	<p>
	Allow applications to use OpenGL buffer, texture and renderbuffer objects as OpenCL memory objects.
	</p>
	</div>
	<div class="refsect2">
	<a id="synopsis"></a>
	<h3>
	</h3>
	<div class="informaltable">
	<table border="0">
	<colgroup>
	<col align="left" class="col1" />
	</colgroup>
	<tbody>
	<tr>
	<td align="left">
	cl_khr_gl_sharing
	</td>
	</tr>
	</tbody>
	</table>
	</div>
	</div>
	<div class="refsect1">
	<a id="description"></a>
	<h2>Description</h2>
	<p>
	This is a Kronos-approved extension
	name. If this extension is supported, "cl_khr_gl_sharing" will
	be returned for <code class="constant">CL_DEVICE_EXTENSIONS</code> using
	<a class="citerefentry" href="clGetDeviceInfo.html"><span class="citerefentry"><span class="refentrytitle">clGetDeviceInfo</span></span></a>.
	</p>
	<p>
	The OpenCL specification in section 9.7 defines how to
	share data with texture and buffer objects in a parallel OpenGL implementation,
	but does not define how the association between an OpenCL context and an OpenGL
	context or share group is established. This extension defines optional attributes
	to OpenCL context creation routines which associate a GL context or share group
	object with a newly created OpenCL context. If this extension is supported by an
	implementation, the string <code class="function">cl_khr_gl_sharing</code> will be present in the
	<code class="constant">CL_PLATFORM_EXTENSIONS</code> or <code class="constant">CL_DEVICE_EXTENSIONS</code>
	string described in the table of allowed values for <code class="varname">param_name</code>
	for <a class="citerefentry" href="clGetDeviceInfo.html"><span class="citerefentry"><span class="refentrytitle">clGetDeviceInfo</span></span></a>
	</p>
	<p>
	An OpenGL implementation supporting buffer objects and
	sharing of texture and buffer object images with OpenCL is required by this extension.
	</p>
	<p>
	This section discusses OpenCL functions that allow applications
	to use OpenGL buffer, texture, and renderbuffer objects as OpenCL memory objects. This
	allows efficient sharing of data between OpenCL and OpenGL. The OpenCL API may be used
	to execute kernels that read and/or write memory objects that are also OpenGL objects.
	</p>
	<p>
	An OpenCL image object may be created from an OpenGL texture or
	renderbuffer object. An OpenCL buffer object may be created from an OpenGL buffer object.
	</p>
	<p>
	OpenCL memory objects may be created from OpenGL objects
	if and only if the OpenCL context has been created from an OpenGL share group
	object or context. OpenGL share groups and contexts are created using platform
	specific APIs such as EGL, CGL, WGL, and GLX. On MacOS X, an OpenCL context may
	be created from an OpenGL share group object using the OpenCL platform extension
	cl_apple_gl_sharing. On other platforms including Microsoft Windows, Linux/Unix and
	others, an OpenCL context may be created from an OpenGL context using the Khronos
	platform extension <code class="function">cl_khr_gl_sharing</code>. Refer to the platform
	documentation for your OpenCL implementation, or visit the Khronos Registry at
	http://www.khronos.org/registry/cl/ for more information.
	</p>
	<p>
	Any supported OpenGL object defined within the GL share
	group object, or the share group associated with the GL context from which the CL
	context is created, may be shared, with the exception of the default OpenGL objects
	(i.e. objects named zero), which may not be shared.
	</p>
	<p>

	</p>
	<p>
	The table below (Table 9.4) describes
	the list of GL texture internal formats and the corresponding CL image formats. If a GL
	texture object with an internal format from the table below is successfully created by
	OpenGL, then there is guaranteed to be a mapping to one of the corresponding CL image
	format(s) in that table. Texture objects created with other OpenGL internal formats may
	(but are not guaranteed to) have a mapping to a CL image format; if such mappings exist,
	they are guaranteed to preserve all color components, data types, and at least the number
	of bits/component actually allocated by OpenGL for that format.
	</p>
	<p>

	</p>
	<div class="informaltable">
	<table border="1">
	<colgroup>
	<col align="center" class="col1" />
	<col align="center" class="col2" />
	</colgroup>
	<thead>
	<tr>
	<th align="center">GL internal format</th>
	<th align="center">CL image format (channel order, channel data type)</th>
	</tr>
	</thead>
	<tbody>
	<tr>
	<td align="center">
	<code class="constant">GL_RGBA8</code>
	</td>
	<td align="center">
	<code class="constant">CL_RGBA, CL_UNORM_INT8 or CL_BGRA, CL_UNORM_INT8</code>
	</td>
	</tr>
	<tr>
	<td align="center"><code class="constant">GL_RGBA</code>, <code class="constant">GL_UNSIGNED_INT_8_8_8_8_REV</code></td>
	<td align="center">
	<code class="constant">CL_RGBA, CL_UNORM_INT8</code>
	</td>
	</tr>
	<tr>
	<td align="center"><code class="constant">GL_BGRA</code>, <code class="constant">GL_UNSIGNED_INT_8_8_8_8_REV</code></td>
	<td align="center">
	<code class="constant">CL_BGRA, CL_UNORM_INT8</code>
	</td>
	</tr>
	<tr>
	<td align="center">
	<code class="constant">GL_RGBA16</code>
	</td>
	<td align="center">
	<code class="constant">CL_RGBA, CL_UNORM_INT16</code>
	</td>
	</tr>
	<tr>
	<td align="center">
	<code class="constant">GL_RGBA8I, GL_RGBA8I_EXT</code>
	</td>
	<td align="center">
	<code class="constant">CL_RGBA, CL_SIGNED_INT8</code>
	</td>
	</tr>
	<tr>
	<td align="center">
	<code class="constant">GL_RGBA16I, GL_RGBA16I_EXT</code>
	</td>
	<td align="center">
	<code class="constant">CL_RGBA, CL_SIGNED_INT16</code>
	</td>
	</tr>
	<tr>
	<td align="center">
	<code class="constant">GL_RGBA32I, GL_RGBA32I_EXT</code>
	</td>
	<td align="center">
	<code class="constant">CL_RGBA, CL_SIGNED_INT32</code>
	</td>
	</tr>
	<tr>
	<td align="center">
	<code class="constant">GL_RGBA8UI, GL_RGBA8UI_EXT</code>
	</td>
	<td align="center">
	<code class="constant">CL_RGBA, CL_UNSIGNED_INT8</code>
	</td>
	</tr>
	<tr>
	<td align="center">
	<code class="constant">GL_RGBA16UI, GL_RGBA16UI_EXT</code>
	</td>
	<td align="center">
	<code class="constant">CL_RGBA, CL_UNSIGNED_INT16</code>
	</td>
	</tr>
	<tr>
	<td align="center">
	<code class="constant">GL_RGBA32UI, GL_RGBA32UI_EXT</code>
	</td>
	<td align="center">
	<code class="constant">CL_RGBA, CL_UNSIGNED_INT32</code>
	</td>
	</tr>
	<tr>
	<td align="center">
	<code class="constant">GL_RGBA16F, GL_RGBA16F_ARB</code>
	</td>
	<td align="center">
	<code class="constant">CL_RGBA, CL_HALF_FLOAT</code>
	</td>
	</tr>
	<tr>
	<td align="center">
	<code class="constant">GL_RGBA32F, GL_RGBA32F_ARB</code>
	</td>
	<td align="center">
	<code class="constant">CL_RGBA, CL_FLOAT</code>
	</td>
	</tr>
	</tbody>
	</table>
	</div>
	<p>





	</p>
	<p>
	In order to ensure data integrity, the application is responsible
	for synchronizing access to shared CL/GL objects by their respective APIs. Failure to
	provide such synchronization may result in race conditions and other undefined behavior
	including non-portability between implementations.
	</p>
	<p>

	</p>
	<p>
	Prior to calling <code class="function">clEnqueueAcquireGLObjects</code>,
	the application must ensure that any pending GL operations which access the objects
	specified in <code class="varname">mem_objects</code> have completed. This may be accomplished
	portably by issuing and waiting for completion of a <code class="function">glFinish</code>
	command on all GL contexts with pending references to these objects. Implementations
	may offer more efficient synchronization methods; for example on some platforms calling
	<code class="function">glFlush</code> may be sufficient, or synchronization may be implicit within
	a thread, or there may be vendor-specific extensions that enable placing a fence in the
	GL command stream and waiting for completion of that fence in the CL command queue. Note
	that no synchronization methods other than <code class="function">glFinish</code> are portable
	between OpenGL implementations at this time.
	</p>
	<p>

	</p>
	<p>
	Similarly, after calling
	<code class="function">clEnqueueReleaseGLObjects</code>, the application is responsible
	for ensuring that any pending OpenCL operations which access the objects specified
	in <code class="varname">mem_objects</code> have completed prior to executing subsequent GL
	commands which reference these objects. This may be accomplished portably by calling
	<a class="citerefentry" href="clWaitForEvents.html"><span class="citerefentry"><span class="refentrytitle">clWaitForEvents</span></span></a> with the
	event object returned by <code class="function">clEnqueueReleaseGLObjects</code>, or by calling
	<a class="citerefentry" href="clFinish.html"><span class="citerefentry"><span class="refentrytitle">clFinish</span></span></a>. As above, some
	implementations may offer more efficient methods.
	</p>
	<p>

	</p>
	<p>
	The application is responsible for maintaining the proper order
	of operations if the CL and GL contexts are in separate threads.
	</p>
	<p>

	</p>
	<p>
	If a GL context is bound to a thread other than the one in which
	<code class="function">clEnqueueReleaseGLObjects</code> is called, changes to any of the objects in
	<code class="varname">mem_objects</code> may not be visible to that context without additional steps
	being taken by the application. For an OpenGL 3.1 (or later) context, the requirements
	are described in Appendix D ("Shared Objects and Multiple Contexts") of the OpenGL 3.1
	Specification. For prior versions of OpenGL, the requirements are implementation-dependent.
	</p>
	<p>

	</p>
	<p>
	Attempting to access the data store of an OpenGL object after
	it has been acquired by OpenCL and before it has been released will result in undefined
	behavior. Similarly, attempting to access a shared CL/GL object from OpenCL before it
	has been acquired by the OpenCL command queue, or after it has been released, will result
	in undefined behavior.
	</p>
	<p>

	</p>
	<p>
	If the
	<a class="citerefentry" href="cl_khr_gl_event.html"><span class="citerefentry"><span class="refentrytitle">cl_khr_gl_event</span></span></a> extension
	is supported, then the OpenCL implementation will ensure that any such pending OpenGL
	operations are complete for an OpenGL context bound to the same thread as the OpenCL
	context. This is referred to as implicit synchronization.
	</p>
	<p>





	</p>
	<h4><a id="id-1.5.9.10"></a>Lifetime of Shared Objects</h4>
	<p>

	</p>
	<p>
	An OpenCL memory object created from an OpenGL object
	(hereinafter refered to as a “shared CL/GL object”) remains valid as long as the
	corresponding GL object has not been deleted. If the GL object is deleted through the GL
	API (e.g. <code class="function">glDeleteBuffers</code>, <code class="function">glDeleteTextures</code>,
	or <code class="function">glDeleteRenderbuffers</code>), subsequent use of the CL buffer or image
	object will result in undefined behavior, including but not limited to possible CL errors
	and data corruption, but may not result in program termination.
	</p>
	<p>

	</p>
	<p>
	The CL context and corresponding command-queues are dependent
	on the existence of the GL share group object, or the share group associated with the
	GL context from which the CL context is created. If the GL share group object or all GL
	contexts in the share group are destroyed, any use of the CL context or command-queue(s)
	will result in undefined behavior, which may include program termination. Applications
	should destroy the CL command-queue(s) and CL context before destroying the corresponding
	GL share group or contexts.
	</p>
	<p>




	</p>
	<h4><a id="id-1.5.10"></a>OpenCL Functions That Allow Sharing</h4>
	<p>
	Click an item in the table for details about that function.
	</p>
	</div>
	<div class="refsect1">
	<a id="springboard"></a>
	<h2></h2>
	<div class="informaltable">
	<table border="1">
	<colgroup>
	<col align="left" class="col1" />
	<col align="left" class="col2" />
	</colgroup>
	<tbody>
	<tr>
	<td align="left">
	<a class="citerefentry" href="clGetGLContextInfoKHR.html">
	<span class="citerefentry">
	<span class="refentrytitle">clGetGLContextInfoKHR</span>
	</span>
	</a>
	</td>
	<td align="left">Query the device.</td>
	</tr>
	<tr>
	<td align="left">
	<a class="citerefentry" href="clCreateFromGLBuffer.html">
	<span class="citerefentry">
	<span class="refentrytitle">clCreateFromGLBuffer</span>
	</span>
	</a>
	</td>
	<td align="left">Creates an OpenCL buffer object from an OpenGL buffer object.</td>
	</tr>
	<tr>
	<td align="left">
	<a class="citerefentry" href="clCreateFromGLTexture.html">
	<span class="citerefentry">
	<span class="refentrytitle">clCreateFromGLTexture</span>
	</span>
	</a>
	</td>
	<td align="left">Creates an OpenCL image object, image array object, or image buffer object from an OpenGL
	texture object, texture array object, texture buffer object, or a single face of an
	OpenGL cubemap texture object.</td>
	</tr>
	<tr>
	<td align="left">
	<a class="citerefentry" href="clCreateFromGLRenderbuffer.html">
	<span class="citerefentry">
	<span class="refentrytitle">clCreateFromGLRenderbuffer</span>
	</span>
	</a>
	</td>
	<td align="left">Creates an OpenCL 2D image object from an OpenGL renderbuffer object.</td>
	</tr>
	<tr>
	<td align="left">
	<a class="citerefentry" href="clGetGLObjectInfo.html">
	<span class="citerefentry">
	<span class="refentrytitle">clGetGLObjectInfo</span>
	</span>
	</a>
	</td>
	<td align="left">Query an OpenGL memory object used to create an OpenCL memory object.</td>
	</tr>
	<tr>
	<td align="left">
	<a class="citerefentry" href="clGetGLTextureInfo.html">
	<span class="citerefentry">
	<span class="refentrytitle">clGetGLTextureInfo</span>
	</span>
	</a>
	</td>
	<td align="left">Get additional information about the GL texture object associated with a memory object.</td>
	</tr>
	<tr>
	<td align="left">
	<a class="citerefentry" href="clEnqueueAcquireGLObjects.html">
	<span class="citerefentry">
	<span class="refentrytitle">clEnqueueAcquireGLObjects</span>
	</span>
	</a>
	</td>
	<td align="left">Acquire OpenCL memory objects that have been created from OpenGL objects.</td>
	</tr>
	<tr>
	<td align="left">
	<a class="citerefentry" href="clEnqueueReleaseGLObjects.html">
	<span class="citerefentry">
	<span class="refentrytitle">clEnqueueReleaseGLObjects</span>
	</span>
	</a>
	</td>
	<td align="left">Release OpenCL memory objects that have been created from OpenGL objects.</td>
	</tr>
	</tbody>
	</table>
	</div>
	</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-1.2-extensions.pdf#page=39" target="OpenCL Spec">OpenCL Specification</a>
	</p>
	</div>
	<div class="refsect1">
	<a id="seealso"></a>
	<h2>Also see</h2>
	<p>
	<a class="citerefentry" href="EXTENSION.html"><span class="citerefentry"><span class="refentrytitle">EXTENSION</span></span></a>,
	<a class="citerefentry" href="clGetGLContextInfoKHR.html"><span class="citerefentry"><span class="refentrytitle">clGetGLContextInfoKHR</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 © 2007-2011 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.
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