<!DOCTYPE refentry [ <!ENTITY % mathent SYSTEM "math.ent"> %mathent; ]>

<refentry xmlns="http://docbook.org/ns/docbook" version="5.0" xml:id="glGetVertexArrayIndexed">
  <info>
    <copyright>
      <year>2014</year>

      <holder>Khronos Group</holder>
    </copyright>
  </info>

  <refmeta>
    <refentrytitle>glGetVertexArrayIndexed</refentrytitle>

    <manvolnum>3G</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>glGetVertexArrayIndexed</refname>

    <refpurpose>retrieve parameters of an attribute of a vertex array
    object</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
    <title>C Specification</title>

    <funcsynopsis>
      <funcprototype>
	<funcdef>void <function>glGetVertexArrayIndexed64iv</function></funcdef>

	<paramdef>GLuint <parameter>vaobj</parameter></paramdef>

	<paramdef>GLuint <parameter>index</parameter></paramdef>

	<paramdef>GLenum <parameter>pname</parameter></paramdef>

	<paramdef>GLint64 *<parameter>param</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>

    <funcsynopsis>
      <funcprototype>
	<funcdef>void <function>glGetVertexArrayIndexediv</function></funcdef>

	<paramdef>GLuint <parameter>vaobj</parameter></paramdef>

	<paramdef>GLuint <parameter>index</parameter></paramdef>

	<paramdef>GLenum <parameter>pname</parameter></paramdef>

	<paramdef>GLint *<parameter>param</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>

  <refsect1 xml:id="parameters">
    <title>Parameters</title>

    <variablelist>
      <varlistentry>
	<term><parameter>vaobj</parameter></term>

	<listitem>
	  <para>Specifies the name of a vertex array object.</para>
	</listitem>
      </varlistentry>

      <varlistentry>
	<term><parameter>index</parameter></term>

	<listitem>
	  <para>Specifies the index of the vertex array object attribute. Must
	  be a number between 0 and
	  (<constant>GL_MAX_VERTEX_ATTRIBS</constant> - 1).</para>
	</listitem>
      </varlistentry>

      <varlistentry>
	<term><parameter>pname</parameter></term>

	<listitem>
	  <para>Specifies the property to be used for the query. For
	  <function>glGetVertexArrayIndexediv</function>, it must be one of
	  the following values:
	  <constant>GL_VERTEX_ATTRIB_ARRAY_ENABLED</constant>,
	  <constant>GL_VERTEX_ATTRIB_ARRAY_SIZE</constant>,
	  <constant>GL_VERTEX_ATTRIB_ARRAY_STRIDE</constant>,
	  <constant>GL_VERTEX_ATTRIB_ARRAY_TYPE</constant>,
	  <constant>GL_VERTEX_ATTRIB_ARRAY_NORMALIZED</constant>,
	  <constant>GL_VERTEX_ATTRIB_ARRAY_INTEGER</constant>,
	  <constant>GL_VERTEX_ATTRIB_ARRAY_LONG</constant>,
	  <constant>GL_VERTEX_ATTRIB_ARRAY_DIVISOR</constant>, or
	  <constant>GL_VERTEX_ATTRIB_RELATIVE_OFFSET</constant>. For
	  <function>glGetVertexArrayIndexed64v</function>, it must be equal to
	  <constant>GL_VERTEX_BINDING_OFFSET</constant>.</para>
	</listitem>
      </varlistentry>

      <varlistentry>
	<term><parameter>param</parameter></term>

	<listitem>
	  <para>Returns the requested value.</para>
	</listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1 xml:id="description">
    <title>Description</title>

    <para><function>glGetVertexArrayIndexediv</function> and
    <function>glGetVertexArrayIndexed64iv</function> provide a way of querying
    parameters of an attribute at an user-specified index of a vertex array
    object. The vertex array object does not have to be bound to the rendering
    context at the time of the call, but must have been bound at least once
    prior to this call.</para>

    <para>The following parameter values can be retrieved with
    <function>glGetVertexArrayIndexediv</function> for each of the attributes
    defined for a vertex array object:</para>

    <para><itemizedlist>
	<listitem>
	  <para><constant>GL_VERTEX_ATTRIB_ARRAY_ENABLED</constant>:
	  <parameter>param</parameter> returns a value that is non-zero (true)
	  if the vertex attribute array for index is enabled and 0 (false) if
	  it is disabled. The initial value is
	  <constant>GL_FALSE</constant>.</para>
	</listitem>

	<listitem>
	  <para><constant>GL_VERTEX_ATTRIB_ARRAY_SIZE</constant>:
	  <parameter>param</parameter> returns a single value, the size of the
	  vertex attribute array for index. The size is the number of values
	  for each element of the vertex attribute array, and it will be 1, 2,
	  3 or 4. The initial value is 4.</para>
	</listitem>

	<listitem>
	  <para><constant>GL_VERTEX_ATTRIB_ARRAY_STRIDE</constant>:
	  <parameter>param</parameter> returns a single value, the array
	  stride for (number of bytes between successive elements in) the
	  vertex attribute array for index. A value of 0 indicates the array
	  elements are stored sequentially in memory. The initial value is
	  0.</para>
	</listitem>

	<listitem>
	  <para><constant>GL_VERTEX_ATTRIB_ARRAY_TYPE</constant>:
	  <parameter>param</parameter> returns a single value, a symbolic
	  constant indicating the array type for the vertex attribute array
	  for index. Possible values are <constant>GL_BYTE</constant>,
	  <constant>GL_DOUBLE</constant>, <constant>GL_FIXED</constant>,
	  <constant>GL_FLOAT</constant>, <constant>GL_HALF_FLOAT</constant>,
	  <constant>GL_INT</constant>,
	  <constant>GL_INT_2_10_10_10_REV</constant>,
	  <constant>GL_SHORT</constant>,
	  <constant>GL_UNSIGNED_BYTE</constant>,
	  <constant>GL_UNSIGNED_SHORT</constant>,
	  <constant>GL_UNSIGNED_INT</constant>,
	  <constant>GL_UNSIGNED_INT_2_10_10_10_REV</constant>, and
	  <constant>GL_UNSIGNED_INT_10F_11F_11F_REV</constant> . The initial
	  value is <constant>GL_FLOAT</constant>.</para>
	</listitem>

	<listitem>
	  <para><constant>GL_VERTEX_ATTRIB_ARRAY_NORMALIZED</constant>:
	  <parameter>param</parameter> returns a single value that is non-zero
	  (true) if fixed-point data types for the vertex attribute array
	  indicated by index are normalized when they are converted to
	  floating-point, and 0 (false) otherwise. The initial value is
	  <constant>GL_FALSE</constant>.</para>
	</listitem>

	<listitem>
	  <para><constant>GL_VERTEX_ATTRIB_ARRAY_INTEGER</constant>:
	  <parameter>param</parameter> returns a single value that is non-zero
	  (true) if fixed-point data types for the vertex attribute array
	  indicated by index have integer data type, and 0 (false) otherwise.
	  The initial value is 0 (<constant>GL_FALSE</constant>).</para>
	</listitem>

	<listitem>
	  <para><constant>GL_VERTEX_ATTRIB_ARRAY_LONG</constant>:
	  <parameter>param</parameter> returns a single value that is non-zero
	  (true) if a vertex attribute is stored as an unconverted double, and
	  0 (false) otherwise. The initial value is 0
	  (<constant>GL_FALSE</constant>).</para>
	</listitem>

	<listitem>
	  <para><constant>GL_VERTEX_ATTRIB_ARRAY_DIVISOR</constant>:
	  <parameter>param</parameter> returns a single value that is the
	  frequency divisor used for instanced rendering. See
	  glVertexAttribDivisor. The initial value is 0.</para>
	</listitem>

	<listitem>
	  <para><constant>GL_VERTEX_ATTRIB_RELATIVE_OFFSET</constant>:
	  <parameter>param</parameter> returns a single value that is the byte
	  offset of the first element relative to the start of the vertex
	  buffer binding specified attribute fetches from. The initial value
	  is 0.</para>
	</listitem>
      </itemizedlist><function>glGetVertexArrayIndexed64iv</function> can be
    used to retrieve <constant>GL_VERTEX_BINDING_OFFSET</constant> parameter
    value for any of the attributes defined for a vertex array object. When
    <parameter>pname</parameter> is set to
    <constant>GL_VERTEX_BINDING_OFFSET</constant>,
    <parameter>param</parameter> returns a single value that is the byte
    offset of the first element in the bound buffer's data store. The initial
    value for this parameter is 0.</para>
  </refsect1>

  <refsect1 xml:id="errors">
    <title>Errors</title>

    <para><constant>GL_INVALID_OPERATION</constant> error is generated if
    <parameter>vaobj</parameter> is not the name of an existing vertex array
    object.</para>

    <para><constant>GL_INVALID_VALUE</constant> error is generated if index is
    greater than or equal to the value of
    <constant>GL_MAX_VERTEX_ATTRIBS</constant>.</para>

    <para><constant>GL_INVALID_ENUM</constant> error is generated if
    <parameter>pname</parameter> is not one of the valid values. For more
    details, please see above.</para>
  </refsect1>

  <refsect1 xml:id="versions"><title>Version Support</title>
	<informaltable>
	    <tgroup cols="13" align="left">
		<xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="apifunchead.xml" xpointer="xpointer(/*/*)"/>
		<tbody>
		    <row>
			<entry><function>glGetVertexArrayIndexed64iv</function></entry>
			<xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="apiversion.xml" xpointer="xpointer(/*/*[@role='45']/*)"/>
		    </row>
		    <row>
			<entry><function>glGetVertexArrayIndexediv</function></entry>
			<xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="apiversion.xml" xpointer="xpointer(/*/*[@role='45']/*)"/>
		    </row>
		</tbody>
	    </tgroup>
	</informaltable>
    </refsect1>

  <refsect1 xml:id="seealso">
    <title>See Also</title>

    <para><citerefentry><refentrytitle>glGetVertexAttrib</refentrytitle></citerefentry>,
      <citerefentry><refentrytitle>glVertexAttribBinding</refentrytitle></citerefentry>,
      <!-- FIX: link to glVertexAttribPointer --> <function>glVertexAttribIPointer</function>,
      <!-- FIX: link to glVertexAttribPointer --> <function>glVertexAttribLPointer</function>,
      <citerefentry><refentrytitle>glVertexAttribPointer</refentrytitle></citerefentry></para>
  </refsect1>

  <refsect1 xml:id="Copyright"><title>Copyright</title>
	<para>
	    Copyright <trademark class="copyright"/> 2014 Khronos Group.
	    This material may be distributed subject to the terms and conditions set forth in
	    the Open Publication License, v 1.0, 8 June 1999.
	    <link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://opencontent.org/openpub/">http://opencontent.org/openpub/</link>.
	</para>
    </refsect1>

</refentry>
