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<title>clGetGLContextInfoKHR</title>
<meta name="generator" content="DocBook XSL Stylesheets V1.79.1" />
<meta name="keywords" content="clGetGLContextInfoKHR" />
</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="clGetGLContextInfoKHR"></a>
<h1>
clGetGLContextInfoKHR
</h1>
<p>
Get OpenGL context information.
</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="pagedisplay">cl_int</a>
<strong class="fsfunc">clGetGLContextInfoKHR</strong>
(</code>
<td>const
<a xmlns="http://www.w3.org/1999/xhtml" class="link" href="enums.html#cl_context_properties" target="pagedisplay">cl_context_properties</a>
 <var xmlns="http://www.w3.org/1999/xhtml" class="pdparam">*properties</var>
, </td>
</td>
</tr>
<tr valign="top">
<td> </td>
<td>
<a xmlns="http://www.w3.org/1999/xhtml" class="link" href="enums.html#cl_gl_context_info" target="pagedisplay">cl_gl_context_info</a>
 <var xmlns="http://www.w3.org/1999/xhtml" class="pdparam">param_name</var>
, </td>
</tr>
<tr valign="top">
<td> </td>
<td>
<a xmlns="http://www.w3.org/1999/xhtml" class="link" href="scalarDataTypes.html" target="pagedisplay">size_t</a>
 <var xmlns="http://www.w3.org/1999/xhtml" class="pdparam">param_value_size</var>
, </td>
</tr>
<tr valign="top">
<td> </td>
<td>
<a xmlns="http://www.w3.org/1999/xhtml" class="link" href="scalarDataTypes.html" target="pagedisplay">void</a>
 <var xmlns="http://www.w3.org/1999/xhtml" class="pdparam">*param_value</var>
, </td>
</tr>
<tr valign="top">
<td> </td>
<td>
<a xmlns="http://www.w3.org/1999/xhtml" class="link" href="scalarDataTypes.html" target="pagedisplay">size_t</a>
 <var xmlns="http://www.w3.org/1999/xhtml" class="pdparam">*param_value_size_ret</var>
<code>)</code></td>
</tr>
</table>
</div>
</div>
<div class="refsect1">
<a id="parameters"></a>
<h2>Parameters</h2>
<div class="variablelist">
<dl class="variablelist">
<dt>
<span class="term"> <code class="varname">properties</code> </span>
</dt>
<dd>
<p>
Points to an attribute list whose format and valid contents
are identical to the <code class="varname">properties</code> argument of
<a class="citerefentry" href="clCreateContext.html"><span class="citerefentry"><span class="refentrytitle">clCreateContext</span></span></a>.
<code class="varname">properties</code> must identify a single valid GL context or
GL share group object.
</p>
</dd>
<dt>
<span class="term"> <code class="varname">param_name</code> </span>
</dt>
<dd>
<p>
A constant that specifies the GL context information to query, and must
be one of the values shown in the table below.
</p>
</dd>
<dt>
<span class="term"> <code class="varname">param_value_size</code> </span>
</dt>
<dd>
<p>
Specifies the size in bytes of memory pointed to by
<code class="varname">param_value</code>. This size must be greater than or equal
to the size of the return type described in the table below.
</p>
</dd>
<dt>
<span class="term"> <code class="varname">param_value</code> </span>
</dt>
<dd>
<p>
A pointer to memory where the result of the query is returned as described
in the table below. If <code class="varname">param_value</code> is NULL, it is ignored.
</p>
</dd>
<dt>
<span class="term"> <code class="varname">param_value_size_ret</code> </span>
</dt>
<dd>
<p>
Returns the actual size in bytes of data being queried by
<code class="varname">param_value</code>. If <code class="varname">param_value_size_ret</code>
is NULL, it is ignored.
</p>
</dd>
</dl>
</div>
<div class="informaltable">
<table class="informaltable" border="1">
<colgroup>
<col align="left" class="col1" />
<col align="left" class="col2" />
<col align="left" class="col3" />
</colgroup>
<thead>
<tr>
<th align="left">param_name</th>
<th align="left">Return Type</th>
<th align="left">Information returned in param_value</th>
</tr>
</thead>
<tbody>
<tr>
<td align="left">
<code class="constant">CL_CURRENT_DEVICE_FOR_GL_CONTEXT_KHR</code>
</td>
<td align="left">cl_device_id</td>
<td align="left">
Return the CL device currently associated with the specified OpenGL context.
</td>
</tr>
<tr>
<td align="left">
<code class="constant">CL_DEVICES_FOR_GL_CONTEXT_KHR</code>
</td>
<td align="left">cl_device_id[]</td>
<td align="left">
List of all CL devices which may be associated with the specified OpenGL context.
</td>
</tr>
</tbody>
</table>
</div>
</div>
<div class="refsect1">
<a id="description"></a>
<h2>Description</h2>
<p>
Get OpenGL context information.
</p>
</div>
<div class="refsect1">
<a id="notes"></a>
<h2>Notes</h2>
<p>
General information about GL sharing follows.
</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 "cl_khr_gl_sharing" will be present in the
<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>
or in the <code class="constant">CL_PLATFORM_EXTENSIONS</code>
string described in the table of allowed values for <code class="varname">param_name</code>
for <a class="citerefentry" href="clGetPlatformInfo.html"><span class="citerefentry"><span class="refentrytitle">clGetPlatformInfo</span></span></a>.
</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>
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>
<h4><a id="id-1.7.7"></a>OpenGL and Corresponding OpenCL Image Formats</h4>
<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>
<div class="informaltable">
<table class="informaltable" 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_SRGBA8_ALPHA8</code>
</td>
<td align="center">
<code class="constant">CL_sRGBA, 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_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_RGBA8_SNORM</code>
</td>
<td align="center">
<code class="constant">CL_RGBA, CL_SNORM_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_RGBA16_SNORM</code>
</td>
<td align="center">
<code class="constant">CL_RGBA, CL_SNORM_INT166</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>
<tr>
<td align="center">
<code class="constant">GL_R8</code>
</td>
<td align="center">
<code class="constant">CL_R, CL_UNORM_INT8 </code>
</td>
</tr>
<tr>
<td align="center">
<code class="constant">GL_R8_SNORM</code>
</td>
<td align="center">
<code class="constant">CL_R, CL_SNORM_INT8 </code>
</td>
</tr>
<tr>
<td align="center">
<code class="constant">GL_R16</code>
</td>
<td align="center">
<code class="constant">CL_R, CL_UNORM_INT16 </code>
</td>
</tr>
<tr>
<td align="center">
<code class="constant">GL_R16_SNORM</code>
</td>
<td align="center">
<code class="constant">CL_R, CL_SNORM_INT16 </code>
</td>
</tr>
<tr>
<td align="center">
<code class="constant">GL_R16F</code>
</td>
<td align="center">
<code class="constant">CL_R, CL_HALF_FLOAT </code>
</td>
</tr>
<tr>
<td align="center">
<code class="constant">GL_R32F</code>
</td>
<td align="center">
<code class="constant">CL_R, CL_FLOAT </code>
</td>
</tr>
<tr>
<td align="center">
<code class="constant">GL_R8I</code>
</td>
<td align="center">
<code class="constant">CL_R, CL_SIGNED_INT8</code>
</td>
</tr>
<tr>
<td align="center">
<code class="constant">GL_R16I</code>
</td>
<td align="center">
<code class="constant">CL_R, CL_SIGNED_INT16</code>
</td>
</tr>
<tr>
<td align="center">
<code class="constant">GL_R32I</code>
</td>
<td align="center">
<code class="constant">CL_R, CL_SIGNED_INT32</code>
</td>
</tr>
<tr>
<td align="center">
<code class="constant">GL_R8UI</code>
</td>
<td align="center">
<code class="constant">CL_R, CL_UNSIGNED_INT8</code>
</td>
</tr>
<tr>
<td align="center">
<code class="constant">GL_R16UI</code>
</td>
<td align="center">
<code class="constant">CL_R, CL_UNSIGNED_INT16</code>
</td>
</tr>
<tr>
<td align="center">
<code class="constant">GL_R32UI</code>
</td>
<td align="center">
<code class="constant">CL_R, CL_UNSIGNED_INT32</code>
</td>
</tr>
<tr>
<td align="center">
<code class="constant">GL_RG8</code>
</td>
<td align="center">
<code class="constant">CL_RG, CL_UNORM_INT8 </code>
</td>
</tr>
<tr>
<td align="center">
<code class="constant">GL_RG8_SNORM</code>
</td>
<td align="center">
<code class="constant">CL_RG, CL_SNORM_INT8</code>
</td>
</tr>
<tr>
<td align="center">
<code class="constant">GL_RG16</code>
</td>
<td align="center">
<code class="constant">CL_RG, CL_UNORM_INT16</code>
</td>
</tr>
<tr>
<td align="center">
<code class="constant">GL_RG16_SNORM</code>
</td>
<td align="center">
<code class="constant">CL_RG, CL_SNORM_INT16 </code>
</td>
</tr>
<tr>
<td align="center">
<code class="constant">GL_RG16F</code>
</td>
<td align="center">
<code class="constant">CL_RG, CL_HALF_FLOAT </code>
</td>
</tr>
<tr>
<td align="center">
<code class="constant">GL_RG32F</code>
</td>
<td align="center">
<code class="constant">CL_RG, CL_FLOAT</code>
</td>
</tr>
<tr>
<td align="center">
<code class="constant">GL_RG8I</code>
</td>
<td align="center">
<code class="constant">CL_RG, CL_SIGNED_INT8</code>
</td>
</tr>
<tr>
<td align="center">
<code class="constant">GL_RG16I</code>
</td>
<td align="center">
<code class="constant">CL_RG, CL_SIGNED_INT16</code>
</td>
</tr>
<tr>
<td align="center">
<code class="constant">GL_RG32I</code>
</td>
<td align="center">
<code class="constant">CL_RG, CL_SIGNED_INT32</code>
</td>
</tr>
<tr>
<td align="center">
<code class="constant">GL_RG8UI</code>
</td>
<td align="center">
<code class="constant">CL_RG, CL_UNSIGNED_INT8</code>
</td>
</tr>
<tr>
<td align="center">
<code class="constant">GL_RG16UI</code>
</td>
<td align="center">
<code class="constant">CL_RG, CL_UNSIGNED_INT16</code>
</td>
</tr>
<tr>
<td align="center">
<code class="constant">GL_RG32UI</code>
</td>
<td align="center">
<code class="constant">CL_RG, CL_UNSIGNED_INT32</code>
</td>
</tr>
</tbody>
</table>
</div>
<p>
If the <a class="citerefentry" href="cl_khr_gl_depth_images.html"><span class="citerefentry"><span class="refentrytitle">cl_khr_gl_depth_images</span></span></a>
extension is enabled, the
following new image formats are added to table 9.4 in section 9.6.3.1 of the OpenCL 2.0
extension specification. If a GL texture object with an internal format from table 9.4 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.
</p>
<div class="informaltable">
<table class="informaltable" 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_DEPTH_COMPONENT32F</code>
</td>
<td align="center">
<code class="constant">CL_DEPTH, CL_FLOAT</code>
</td>
</tr>
<tr>
<td align="center">
<code class="constant">GL_DEPTH_COMPONENT16</code>
</td>
<td align="center">
<code class="constant">CL_DEPTH, CL_UNORM_INT16</code>
</td>
</tr>
<tr>
<td align="center">
<code class="constant">GL_DEPTH24_STENCIL8</code>
</td>
<td align="center">
<code class="constant">CL_DEPTH_STENCIL, CL_UNORM_INT24</code>
</td>
</tr>
<tr>
<td align="center">
<code class="constant">GL_DEPTH32F_STENCIL8</code>
</td>
<td align="center">
<code class="constant">CL_DEPTH_STENCIL, CL_FLOAT</code>
</td>
</tr>
</tbody>
</table>
</div>
<h4><a id="id-1.7.12"></a>Lifetime of [GL] Shared Objects</h4>
<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>
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>
<h4><a id="id-1.7.15"></a>Synchronizing OpenCL and OpenGL Access</h4>
<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>
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>
When the extension
<a class="citerefentry" href="cl_khr_egl_event.html"><span class="citerefentry"><span class="refentrytitle">cl_khr_egl_event</span></span></a>
is supported: Prior to calling
<code class="function">clEnqueueAcquireGLObjects</code>,
the application must ensure that any pending
EGL or EGL client API operations which access
the objects specified in <code class="varname">mem_objects</code> have
completed.
If the
<a class="citerefentry" href="cl_khr_egl_event.html"><span class="citerefentry"><span class="refentrytitle">cl_khr_egl_event</span></span></a>
extension is supported and the EGL context in question supports fence
sync objects, <span class="emphasis"><em>explicit synchronisation</em></span> can be achieved
as set out in section 5.7.1.
If the
<a class="citerefentry" href="cl_khr_egl_event.html"><span class="citerefentry"><span class="refentrytitle">cl_khr_egl_event</span></span></a>
extension is not supported, completion of EGL client API commands
may be determined by issuing and waiting for completion of commands such as
<code class="function">glFinish</code> or
<code class="function">vgFinish</code> on all client API
contexts with pending references to these objects. Some
implementations may offer other efficient
synchronization methods. If such methods exist they
will be described in platform-specific documentation.
Note that no synchronization methods other than
<code class="function">glFinish</code> and <code class="function">vgFinish</code>
are portable between all
EGL client API implementations and all OpenCL
implementations. While this is the only way to
ensure completion that is portable to all platforms,
these are expensive operation and their use
should be avoided if the
<a class="citerefentry" href="cl_khr_egl_event.html"><span class="citerefentry"><span class="refentrytitle">cl_khr_egl_event</span></span></a> extension
is supported on a platform.
</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>
The application is responsible for maintaining the proper order
of operations if the CL and GL contexts are in separate threads.
</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>
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>
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>
</div>
<div class="refsect1">
<a id="errors"></a>
<h2>Errors</h2>
<p>
Returns <span class="errorname">CL_SUCCESS</span> if the function is executed successfully.
If no device(s) exist corresponding to <code class="varname">param_name</code>, the call will not
fail, but the value of <code class="varname">param_value_size_ret</code> will be zero. Otherwise
returns one of the following:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem" style="list-style-type: disc"><span class="errorname">CL_INVALID_GL_SHAREGROUP_REFERENCE_KHR</span> if a context was
specified by any of the following means:
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem" style="list-style-type: disc">
A context was specified for an
EGL-based OpenGL ES or OpenGL implementation by setting
the attributes <code class="constant">CL_GL_CONTEXT_KHR</code> and
<code class="constant">CL_EGL_DISPLAY_KHR</code></li><li class="listitem" style="list-style-type: disc">
A context was specified
for a GLX-based OpenGL implementation by setting the
attributes <code class="constant">CL_GL_CONTEXT_KHR</code> and
<code class="constant">CL_GLX_DISPLAY_KHR</code></li><li class="listitem" style="list-style-type: disc">
A context was specified
for a WGL-based OpenGL implementation by setting the
attributes <code class="constant">CL_GL_CONTEXT_KHR</code> and
<code class="constant">CL_WGL_HDC_KHR</code></li></ul></div><p>
and any of the following conditions hold:
</p><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem" style="list-style-type: disc">
The specified display and context attributes do
not identify a valid OpenGL or OpenGL ES context.
</li><li class="listitem" style="list-style-type: disc">
The specified context does not support buffer and renderbuffer objects.
</li><li class="listitem" style="list-style-type: disc">
The specified context is not compatible with
the OpenCL context being created (for example, it exists in a physically
distinct address space, such as another hardware device; or it does not
support sharing data with OpenCL due to implementation restrictions).
</li></ul></div></li>
<li class="listitem" style="list-style-type: disc">
<p>
<span class="errorname">CL_INVALID_GL_SHAREGROUP_REFERENCE_KHR</span> if a share group
was specified for a CGL-based OpenGL implementation by setting the attribute
<code class="constant">CL_CGL_SHAREGROUP_KHR</code>, and the specified share group
does not identify a valid CGL share group object.
</p>
</li>
<li class="listitem" style="list-style-type: disc">
<p>
<span class="errorname">CL_INVALID_OPERATION</span> if a context was specified as
described above and any of the following conditions hold:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem" style="list-style-type: disc">
A context or share group object was specified
for one of CGL, EGL, GLX, or WGL and the OpenGL implementation does not
support that window-system binding API.
</li>
<li class="listitem" style="list-style-type: disc">
More than one of the attributes <code class="constant">CL_CGL_SHAREGROUP_KHR</code>,
<code class="constant">CL_EGL_DISPLAY_KHR</code>,
<code class="constant">CL_GLX_DISPLAY_KHR</code>, and
<code class="constant">CL_WGL_HDC_KHR</code> is set to a non-default value.
</li>
<li class="listitem" style="list-style-type: disc">
Both of the attributes <code class="constant">CL_CGL_SHAREGROUP_KHR</code> and
<code class="constant">CL_GL_CONTEXT_KHR</code> are set to non-default values.
</li>
<li class="listitem" style="list-style-type: disc">
Any of the devices specified in the <code class="varname">devices</code> argument
cannot support OpenCL objects which share the data store of an OpenGL object.
</li>
</ul>
</div>
</li>
<li class="listitem" style="list-style-type: disc"><span class="errorname">CL_INVALID_VALUE</span> if an attribute name
other than those specified in the table of supported <code class="varname">properties</code>
for <a class="citerefentry" href="clCreateContext.html"><span class="citerefentry"><span class="refentrytitle">clCreateContext</span></span></a>
is specified in <code class="varname">properties</code>.
</li>
<li class="listitem" style="list-style-type: disc"><span class="errorname">CL_INVALID_VALUE</span>
if <code class="varname">param_name</code> is not one of the values listed
in the table above; or if the size in bytes specified
by <code class="varname">param_value_size</code> is less than the size of the return type
shown in the table above, and
<code class="varname">param_value</code> is not a NULL value.
</li>
<li class="listitem" style="list-style-type: disc"><span class="errorname">CL_OUT_OF_RESOURCES</span> if there is a failure to allocate
resources required by the OpenCL implementation on the device
</li>
<li class="listitem" style="list-style-type: disc"><span class="errorname">CL_OUT_OF_HOST_MEMORY</span> if there
is a failure to allocate resources required by the OpenCL implementation on the host.
</li>
</ul>
</div>
</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-2.1-extensions.pdf#page=41" target="OpenCL Spec">OpenCL Specification</a>
</p>
</div>
<div class="refsect1">
<a id="seealso"></a>
<h2>Also see</h2>
<p>
<a class="citerefentry" href="clCreateContext.html"><span class="citerefentry"><span class="refentrytitle">clCreateContext</span></span></a>,
<a class="citerefentry" href="cl_khr_gl_sharing.html"><span class="citerefentry"><span class="refentrytitle">cl_khr_gl_sharing</span></span></a>,
<a class="citerefentry" href="cl_khr_gl_event.html"><span class="citerefentry"><span class="refentrytitle">cl_khr_gl_event</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.
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