sdk/1.1/docs/man/gl_sharing.xml

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<refentry>
    <refentryinfo>
        <keywordset>
            <keyword>gl_sharing</keyword>
        </keywordset>
    </refentryinfo>

    <refmeta>                                    
        <refentrytitle>gl_sharing</refentrytitle>

        <refmiscinfo>
            <copyright>
                <year>2007-2010</year>
                <holder>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.</holder>
            </copyright>
        </refmiscinfo>
        <manvolnum>3</manvolnum>
    </refmeta>

<!-- ================================ SYNOPSIS -->

    <refnamediv id="gl_sharing">             
        <refname>gl_sharing</refname>

        <refpurpose>
Allow applications to use OpenGL buffer, texture
and renderbuffer objects as OpenCL memory objects.
        </refpurpose>
    </refnamediv>


    <!-- ALTERNATIVE SYNTAX SYNOPSIS (NON-FUNCTION) -->
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        </title>

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                        <entry>
#pragma OPENCL EXTENSION CL_APPLE_gl_sharing : enable
#pragma OPENCL EXTENSION CL_KHR_gl_sharing : enable
                        </entry>
                    </row>
                </tbody>
            </tgroup>
        </informaltable>
    </refsect2>


<!-- ================================ DESCRIPTION  -->


    <refsect1 xmlns:xlink="http://www.w3.org/1999/xlink" id="description"><title>Description</title>
        <para>
These OpenCL functions 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. 
        </para>

        <para>
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.
        </para>

        <para>
OpenCL memory objects may be created from OpenGL objects 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. 
        </para>

        <para>
On MacOS X, an OpenCL context may be created from an OpenGL share group object using the OpenCL platform extension <function>cl_apple_gl_sharing</function>.     
        </para>

        <para>
        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 <function>cl_khr_gl_sharing</function>. Refer to the platform documentation for your OpenCL implementation, or visit the Khronos Registry at <ulink url="http://www.khronos.org/registry/cl/">http://www.khronos.org/registry/cl/</ulink> for more information. 

        </para>

        <para>
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.
        </para>   
        
        <bridgehead>Lifetime of Shard Objects</bridgehead>
        
        <para>
        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. glDeleteBuffers, glDeleteTextures, or
glDeleteRenderbuffers), 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.
        </para>

        <para>
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
        </para>
    </refsect1>
    

        <bridgehead>OpenCL Functions That Allow Sharing</bridgehead>
        <para>
            Click an item in the table for details about that function.
        </para>


<refsect1 id="springboard"><title></title>
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    <colspec colnum="1" colwidth="25*" colname="col1" />
    <colspec colnum="2" colwidth="25*" colname="col2" />
    <tbody>
        <row>
            <entry><citerefentry><refentrytitle>clCreateFromGLBuffer</refentrytitle></citerefentry></entry>
            <entry>Creates an OpenCL buffer object from an OpenGL buffer object.</entry>
        </row>
        <row>
            <entry><citerefentry><refentrytitle>clCreateFromGLTexture2D</refentrytitle></citerefentry></entry>
            <entry>Creates an OpenCL 2D image object from an OpenGL 2D texture object, or a single face of an
OpenGL cubemap texture object.</entry>
        </row>
        <row>
            <entry><citerefentry><refentrytitle>clCreateFromGLTexture3D</refentrytitle></citerefentry></entry>
            <entry>Creates an OpenCL 3D image object from an OpenGL 3D texture object.</entry>
        </row>
        <row>
            <entry><citerefentry><refentrytitle>clCreateFromGLRenderbuffer</refentrytitle></citerefentry></entry>
            <entry>Creates an OpenCL 2D image object from an OpenGL renderbuffer object.</entry>
        </row>
        <row>
            <entry><citerefentry><refentrytitle>clGetGLObjectInfo</refentrytitle></citerefentry></entry>
            <entry>Query an OpenGL memory object used to create an OpenCL memory object.</entry>
        </row>
        <row>
            <entry><citerefentry><refentrytitle>clGetGLTextureInfo</refentrytitle></citerefentry></entry>
            <entry>Get additional information about the GL texture object associated with a memory object.</entry>
        </row>
        <row>
            <entry><citerefentry><refentrytitle>clEnqueueAcquireGLObjects</refentrytitle></citerefentry></entry>
            <entry>Acquire OpenCL memory objects that have been created from OpenGL objects.</entry>
        </row>
        <row>
            <entry><citerefentry><refentrytitle>clEnqueueReleaseGLObjects</refentrytitle></citerefentry></entry>
            <entry>Release OpenCL memory objects that have been created from OpenGL objects.</entry>
        </row>
    </tbody></tgroup>
</informaltable>    
</refsect1>
    

<!-- ================================ EXAMPLE  -->
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<!-- ================================ SPECIFICATION  -->
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    <refsect1 id="specification"><title>Specification</title>
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            <olink uri="gl_sharing">OpenCL Specification</olink>
        </para>
    </refsect1>


<!-- ================================ ALSO SEE -->

    <refsect1 id="seealso"><title>Also see</title>
        <para>
            <citerefentry><refentrytitle>EXTENSION</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>clGetGLContextInfoKHR</refentrytitle></citerefentry>
        </para>
    </refsect1>



<!-- ============================== COPYRIGHT -->
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