sdk/1.2/docs/man/clGetGLContextInfoKHR.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN"
              "http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd">

<refentry>
    <refentryinfo>
        <keywordset>
            <keyword>clGetGLContextInfoKHR</keyword>
        </keywordset>
    </refentryinfo>

    <refmeta>
        <refentrytitle>
            clGetGLContextInfoKHR
        </refentrytitle>

        <refmiscinfo>
            <copyright>
                <year>2007-2011</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="clGetGLContextInfoKHR">
        <refname>
            clGetGLContextInfoKHR
        </refname>

        <refpurpose>
             Get OpenGL context information.
        </refpurpose>
    </refnamediv>

    <refsynopsisdiv xmlns:xlink="http://www.w3.org/1999/xlink"><title></title>
        <funcsynopsis>
            <funcprototype>
                <funcdef>
                    <link xlink:href="scalarDataTypes.html">cl_int</link>
                    <function>clGetGLContextInfoKHR</function>
                </funcdef>

                <paramdef>const
                    <link xlink:href="enums.html#cl_context_properties">cl_context_properties</link>
                    <parameter>*properties</parameter>
                </paramdef>

                <paramdef>
                    <link xlink:href="enums.html#cl_gl_context_info">cl_gl_context_info</link>
                    <parameter>param_name</parameter>
                </paramdef>

                <paramdef>
                    <link xlink:href="scalarDataTypes.html">size_t</link>
                    <parameter>param_value_size</parameter>
                </paramdef>

                <paramdef>
                    <link xlink:href="scalarDataTypes.html">void</link>
                    <parameter>*param_value</parameter>
                </paramdef>

                <paramdef>
                    <link xlink:href="scalarDataTypes.html">size_t</link>
                    <parameter>*param_value_size_ret</parameter>
                </paramdef>

            </funcprototype>
        </funcsynopsis>
    </refsynopsisdiv>

<!-- ================================ PARAMETERS -->
<!-- For each <varlistentry />, place the parameter name in <term /><varname />, then the definition in
     <listitem /><para />. When refering to anything
     that has a page in this system, use <citerefentry /><refentrytitle /> to make it a link.
 -->

    <refsect1 id="parameters">
        <title>Parameters</title>
        <variablelist>
            <varlistentry>
                <term> <varname>properties</varname> </term>
                <listitem>
                    <para>
                      Points to an attribute list whose format and valid contents
                      are identical to the <varname>properties</varname> argument of
                      <citerefentry><refentrytitle>clCreateContext</refentrytitle></citerefentry>.
                      <varname>properties</varname> must identify a single valid GL context or
                      GL share group object.
                    </para>
               </listitem>
            </varlistentry>

            <varlistentry>
                <term> <varname>param_name</varname> </term>
                <listitem>
                    <para>
                      A constant that specifies the GL context information to query, and must
                      be one of the values shown in the table below.
                    </para>
               </listitem>
            </varlistentry>

            <varlistentry>
                <term> <varname>param_value_size</varname> </term>
                <listitem>
                    <para>
                      Specifies the size in bytes of memory pointed to by
                      <varname>param_value</varname>.  This size must be greater than or equal
                      to the size of the return type described in the table below.
                    </para>
               </listitem>
            </varlistentry>

            <varlistentry>
                <term> <varname>param_value</varname> </term>
                <listitem>
                    <para>
                      A pointer to memory where the result of the query is returned as described
                      in the table below. If <varname>param_value</varname> is NULL, it is ignored.
                    </para>
               </listitem>
            </varlistentry>

            <varlistentry>
                <term> <varname>param_value_size_ret</varname> </term>
                <listitem>
                    <para>
                      Returns the actual size in bytes of data being queried by
                      <varname>param_value</varname>.  If <varname>param_value_size_ret</varname>
                      is NULL, it is ignored.
                    </para>
               </listitem>
            </varlistentry>
        </variablelist>

        <informaltable frame="all">
            <tgroup cols="3" align="left" colsep="1" rowsep="1">
                <colspec colname="col1" colnum="1" />
                <colspec colname="col2" colnum="2" />
                <colspec colname="col3" colnum="3" />
                <thead>
                    <row>
                        <entry>param_name</entry>
                        <entry>Return Type</entry>
                        <entry>Information returned in param_value</entry>
                    </row>
                </thead>

                <tbody>
                    <row>
                        <entry><constant>CL_CURRENT_DEVICE_FOR_GL_CONTEXT_KHR</constant></entry>
                        <entry>cl_device_id</entry>
                        <entry>Return the CL device currently associated with the specified OpenGL context.</entry>
                    </row>

                    <row>
                        <entry><constant>CL_DEVICES_FOR_GL_CONTEXT_KHR</constant></entry>
                        <entry>cl_device_id[]</entry>
                        <entry>List of all CL devices which may be associated with the specified OpenGL context.</entry>
                    </row>

                </tbody>
            </tgroup>
        </informaltable>
    </refsect1>

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

    <refsect1 id="description"><title>Description</title>
        <para>
          The OpenGL object used to create the OpenCL memory object and information about
          the object type i.e. whether it is a texture, renderbuffer, or buffer object can be
          queried using this function.
        </para>
    </refsect1>

<!-- ================================ NOTES  -->

    <refsect1 id="notes"><title>Notes</title>
        <para>
          <!-- ext. spec p. 39 --> 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
          <constant>CL_PLATFORM_EXTENSIONS</constant> or <constant>CL_DEVICE_EXTENSIONS</constant>
          string described in the table of allowed values for <varname>param_name</varname>
          for <citerefentry><refentrytitle>clGetDeviceInfo</refentrytitle></citerefentry>.
        </para>

        <para>
          <!-- ext. spec p. 39 --> An OpenGL implementation supporting buffer objects and
          sharing of texture and buffer object images with OpenCL is required by this extension.
        </para>

        <para>
          <!-- ext. spec p. 42 --> OpenCL device(s) corresponding to an OpenGL context may be
          queried. Such a device may not always exist (for example, if an OpenGL context is
          specified on a GPU not supporting OpenCL command queues, but which does support shared
          CL/GL objects), and if it does exist, may change over time. When such a device does
          exist, acquiring and releasing shared CL/GL objects may be faster on a command queue
          corresponding to this device than on command queues corresponding to other devices
          available to an OpenCL context.
        </para>
    </refsect1>

<!-- ================================ ERRORS     -->

    <refsect1 id="errors">
        <title>Errors</title>
        <para>
          Returns <errorname>CL_SUCCESS</errorname> if the function is executed successfully.
          If no device(s) exist corresponding to <varname>param_name</varname>, the call will not
          fail, but the value of <varname>param_value_size_ret</varname> will be zero. Otherwise
          returns one of the following:
        </para>

        <itemizedlist mark="disc">
            <listitem>
                <para><!-- ext. spec p. 39 -->
                    <errorname>CL_INVALID_GL_SHAREGROUP_REFERENCE_KHR</errorname> when an
                    invalid OpenGL context or share group object handle is specified in
                    <varname>properties</varname>.
                </para>

            </listitem>

            <listitem><!-- ext. spec p. 42 -->
                <errorname>CL_INVALID_GL_SHAREGROUP_REFERENCE_KHR</errorname> if a context was
                    specified by any of the following means:

                <itemizedlist mark="disc">
                    <listitem>
                      <!-- ext. spec p. 43 --> A context was specified for an
                      EGL-based OpenGL ES or OpenGL implementation by setting
                      the attributes <constant>CL_GL_CONTEXT_KHR</constant> and
                      <constant>CL_EGL_DISPLAY_KHR</constant>
                    </listitem>

                    <listitem>
                      <!-- ext. spec p. 44 --> A context was specified
                      for a GLX-based OpenGL implementation by setting the
                      attributes <constant>CL_GL_CONTEXT_KHR</constant> and
                      <constant>CL_GLX_DISPLAY_KHR</constant>
                    </listitem>

                    <listitem>
                      <!-- ext. spec p. 44 --> A context was specified
                      for a WGL-based OpenGL implementation by setting the
                      attributes <constant>CL_GL_CONTEXT_KHR</constant> and
                      <constant>CL_WGL_HDC_KHR</constant>
                    </listitem>
                </itemizedlist>

                <para>
                    and any of the following conditions hold:
                </para>

                <itemizedlist mark="disc">
                    <listitem>
                      <!-- ext. spec p. 44 --> The specified display and context attributes do
                      not identify a valid OpenGL or OpenGL ES context.
                    </listitem>

                    <listitem><!-- ext. spec p. 44 -->
                        The specified context does not support buffer and renderbuffer objects.
                    </listitem>

                    <listitem>
                      <!-- ext. spec p. 44 --> 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).
                    </listitem>
                </itemizedlist>
            </listitem>

            <listitem>
                <para>
                  <errorname>CL_INVALID_GL_SHAREGROUP_REFERENCE_KHR</errorname> if a share group
                  was specified for a CGL-based OpenGL implementation by setting the attribute
                  <constant>CL_CGL_SHAREGROUP_KHR</constant>, and the specified share group
                  does not identify a valid CGL share group object.
                </para>
            </listitem>

            <listitem><!-- ext. spec p. 44 -->
                <para>
                    <errorname>CL_INVALID_OPERATION</errorname> if a context was specified as
                    described above and any of the following conditions hold:
                </para>

                <itemizedlist mark="disc">
                    <listitem>
                      <!-- ext. spec p. 44 --> 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.
                    </listitem>

                    <listitem>
                      More than one of the attributes <constant>CL_CGL_SHAREGROUP_KHR</constant>,
                      <constant>CL_EGL_DISPLAY_KHR</constant>,
                      <constant>CL_GLX_DISPLAY_KHR</constant>, and
                      <constant>CL_WGL_HDC_KHR</constant> is set to a non-default value.
                    </listitem>

                    <listitem>
                        Both of the attributes <constant>CL_CGL_SHAREGROUP_KHR</constant> and
                        <constant>CL_GL_CONTEXT_KHR</constant> are set to non-default values.
                    </listitem>

                    <listitem>
                      Any of the devices specified in the <varname>devices</varname> argument
                      cannot support OpenCL objects which share the data store of an OpenGL object.
                    </listitem>
                </itemizedlist>
            </listitem>

            <listitem>
              <!-- ext. spec p. 44 --> <errorname>CL_INVALID_VALUE</errorname> if an attribute name
              other than those specified in the table of supported <varname>properties</varname>
              for <citerefentry><refentrytitle>clCreateContext</refentrytitle></citerefentry>
              is specified in <varname>properties</varname>.
            </listitem>

            <listitem>
              <!-- ext. spec p. 44 --> <errorname>CL_INVALID_VALUE</errorname>
              if <varname>param_name</varname> is not
              <constant>CL_CURRENT_DEVICE_FOR_GL_CONTEXT_KHR</constant> or
              <constant>CL_DEVICES_FOR_GL_CONTEXT_KHR</constant>; or if the size in bytes specified
              by <varname>param_value_size</varname> is less than the size of the return type
              shown above for <constant>CL_CURRENT_DEVICE_FOR_GL_CONTEXT_KHR</constant>
              or <constant>CL_DEVICES_FOR_GL_CONTEXT_KHR</constant>; and
              <varname>param_value</varname> is not a NULL value.
            </listitem>

            <listitem>
              <!-- ext. spec p. 44, starts in the middle of a paragraph -->
              <errorname>CL_OUT_OF_RESOURCES</errorname> if there is a failure to allocate
              resources required by the OpenCL implementation on the device
            </listitem>

            <listitem>
              <!-- ext. spec p. 44 --> <errorname>CL_OUT_OF_HOST_MEMORY</errorname> if there
              is a failure to allocate resources required by the OpenCL implementation on the host.
            </listitem>
        </itemizedlist>
    </refsect1>

<!-- ================================ EXAMPLE  -->
<!-- DO NOT DELETE IN CASE AN EXAMPLE IS ADDED IN THE FUTURE -->
<!--
    <refsect2 id="example1">
        <title>
            Example
        </title>

        <informaltable frame="none">
            <tgroup cols="1" align="left" colsep="0" rowsep="0">
                <colspec colname="col1" colnum="1" />
                <tbody>
                    <row>
                        <entry>
                            Example goes here - it will be set in "code" type with white space preserved.
                        </entry>
                    </row>
                </tbody>
            </tgroup>
        </informaltable>
    </refsect2>
-->

<!-- ================================ SPECIFICATION  -->
<!-- Set the "uri" attribute in the <olink /> element to the "named destination" for the PDF page
-->
    <refsect1 id="specification"><title>Specification</title>
        <para>
            <imageobject>
                <imagedata fileref="pdficon_small1.gif" format="gif" />
            </imageobject>

            <olink uri="clGetGLContextInfoKHR">OpenCL Specification</olink>
        </para>
    </refsect1>

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

    <refsect1 id="seealso"><title>Also see</title>
        <para>
            <citerefentry><refentrytitle>clCreateContext</refentrytitle></citerefentry>
            <citerefentry><refentrytitle>cl_khr_gl_sharing</refentrytitle></citerefentry>
        </para>
    </refsect1>

<!-- ================================ COPYRIGHT  -->
<!-- Content included from copyright.inc.xsl -->

    <refsect3 id="Copyright"><title></title>
        <imageobject>
                <imagedata fileref="KhronosLogo.jpg" format="jpg" />
        </imageobject>
        <para />
    </refsect3>

<!-- 24-Oct-2011 -->
</refentry>