Opentk/Source/Bind/Specifications/Docs/glGetQueryiv.xml

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<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN"
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<refentry id="glGetQueryiv">
    <refmeta>
        <refmetainfo>
            <copyright>
                <year>2005</year>
                <holder>Sams Publishing</holder>
            </copyright>
        </refmetainfo>
        <refentrytitle>glGetQueryiv</refentrytitle>
        <manvolnum>3G</manvolnum>
    </refmeta>
    <refnamediv>
        <refname>glGetQueryiv</refname>
        <refpurpose>return parameters of a query object target</refpurpose>
    </refnamediv>
    <refsynopsisdiv><title>C Specification</title>
        <funcsynopsis>
            <funcprototype>
                <funcdef>void <function>glGetQueryiv</function></funcdef>
                <paramdef>GLenum <parameter>target</parameter></paramdef>
                <paramdef>GLenum <parameter>pname</parameter></paramdef>
                <paramdef>GLint * <parameter>params</parameter></paramdef>
            </funcprototype>
        </funcsynopsis>
    </refsynopsisdiv>
    <refsect1 id="parameters"><title>Parameters</title>
        <variablelist>
        <varlistentry>
            <term><parameter>target</parameter></term>
            <listitem>
                <para>
                    Specifies a query object target.
                    Must be <constant>GL_SAMPLES_PASSED</constant>.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>pname</parameter></term>
            <listitem>
                <para>
                    Specifies the symbolic name of a query object target parameter.
                    Accepted values are <constant>GL_CURRENT_QUERY</constant> or <constant>GL_QUERY_COUNTER_BITS</constant>.
                </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>params</parameter></term>
            <listitem>
                <para>
                    Returns the requested data.
                </para>
            </listitem>
        </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 id="description"><title>Description</title>
        <para>
            <function>glGetQueryiv</function> returns in <parameter>params</parameter> a selected parameter of the query object target
            specified by <parameter>target</parameter>.
        </para>
        <para>
            <parameter>pname</parameter> names a specific query object target parameter.  When <parameter>target</parameter> is 
            <constant>GL_SAMPLES_PASSED</constant>, <parameter>pname</parameter> can be as follows:
        </para>
        <variablelist>
            <varlistentry>
                <term><constant>GL_CURRENT_QUERY</constant></term>
                <listitem>
                    <para>
                        <parameter>params</parameter> returns the name of the currently active occlusion query object.
                        If no occlusion query is active, 0 is returned.  The initial value is 0.
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term><constant>GL_QUERY_COUNTER_BITS</constant></term>
                <listitem>
                    <para>
                        <parameter>params</parameter> returns the number of bits in the query counter used to accumulate passing samples.
                        If the number of bits returned is 0, the implementation does not support a query counter, and the results 
                        obtained from <citerefentry><refentrytitle>glGetQueryObject</refentrytitle></citerefentry> are useless.
                    </para>
                </listitem>
            </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 id="notes"><title>Notes</title>
        <para>
            If an error is generated,
            no change is made to the contents of <parameter>params</parameter>.
        </para>
        <para>
            <function>glGetQueryiv</function> is available only if the GL version is 1.5 or greater.
        </para>
    </refsect1>
    <refsect1 id="errors"><title>Errors</title>
        <para>
            <constant>GL_INVALID_ENUM</constant> is generated if <parameter>target</parameter> or <parameter>pname</parameter> is not an
            accepted value.
        </para>
        <para>
            <constant>GL_INVALID_OPERATION</constant> is generated if <function>glGetQueryiv</function>
            is executed between the execution of <citerefentry><refentrytitle>glBegin</refentrytitle></citerefentry>
            and the corresponding execution of <citerefentry><refentrytitle>glEnd</refentrytitle></citerefentry>.
        </para>
    </refsect1>
    <refsect1 id="seealso"><title>See Also</title>
        <para>
            <citerefentry><refentrytitle>glGetQueryObject</refentrytitle></citerefentry>,
            <citerefentry><refentrytitle>glIsQuery</refentrytitle></citerefentry>
        </para>
    </refsect1>
    <refsect1 id="Copyright"><title>Copyright</title>
        <para>
            Copyright <trademark class="copyright"></trademark> 2005 Addison-Wesley. 
            This material may be distributed subject to the terms and conditions set forth in 
            the Open Publication License, v 1.0, 8 June 1999.
            <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.
        </para>
    </refsect1>
</refentry>