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

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<refentry xmlns="http://docbook.org/ns/docbook" version="5.0" xml:id="glGetActiveUniformsiv">
    <info>
        <copyright>
            <year>2003-2005</year>
            <holder>3Dlabs Inc. Ltd.</holder>
        </copyright>
        <copyright>
            <year>2010-2014</year>
            <holder>Khronos Group</holder>
        </copyright>
    </info>
    <refmeta>
        <refentrytitle>glGetActiveUniformsiv</refentrytitle>
        <manvolnum>3G</manvolnum>
    </refmeta>
    <refnamediv>
        <refname>glGetActiveUniformsiv</refname>
        <refpurpose>Returns information about several active uniform variables for the specified program object</refpurpose>
    </refnamediv>
    <refsynopsisdiv><title>C Specification</title>
    <funcsynopsis>
        <funcprototype>
        <funcdef>void <function>glGetActiveUniformsiv</function></funcdef>
        <paramdef>GLuint <parameter>program</parameter></paramdef>
        <paramdef>GLsizei <parameter>uniformCount</parameter></paramdef>
        <paramdef>const GLuint *<parameter>uniformIndices</parameter></paramdef>
        <paramdef>GLenum <parameter>pname</parameter></paramdef>
        <paramdef>GLint *<parameter>params</parameter></paramdef>
        </funcprototype>
    </funcsynopsis>
    </refsynopsisdiv>
    <refsect1 xml:id="parameters"><title>Parameters</title>
    <variablelist>
        <varlistentry>
        <term><parameter>program</parameter></term>
        <listitem>
            <para>Specifies the program object to be queried.</para>
        </listitem>
        </varlistentry>
        <varlistentry>
        <term><parameter>uniformCount</parameter></term>
        <listitem>
            <para>Specifies both the number of elements in the array of indices <parameter>uniformIndices</parameter> and the
            number of parameters written to <parameter>params</parameter> upon successful return.</para>
        </listitem>
        </varlistentry>
        <varlistentry>
        <term><parameter>uniformIndices</parameter></term>
        <listitem>
            <para>Specifies the address of an array of <parameter>uniformCount</parameter> integers containing the indices of
            uniforms within <parameter>program</parameter> whose parameter <parameter>pname</parameter> should be queried.</para>
        </listitem>
        </varlistentry>
        <varlistentry>
        <term><parameter>pname</parameter></term>
        <listitem>
            <para>Specifies the property of each uniform in <parameter>uniformIndices</parameter> that should be
            written into the corresponding element of <parameter>params</parameter>.</para>
        </listitem>
        </varlistentry>
        <varlistentry>
        <term><parameter>params</parameter></term>
        <listitem>
            <para>Specifies the address of an array of <parameter>uniformCount</parameter> integers which are to
            receive the value of <parameter>pname</parameter> for each uniform in <parameter>uniformIndices</parameter>.</para>
        </listitem>
        </varlistentry>
    </variablelist>
    </refsect1>
    <refsect1 xml:id="description"><title>Description</title>
        <para>
            <function>glGetActiveUniformsiv</function> queries the value of the parameter named <parameter>pname</parameter>
            for each of the uniforms within <parameter>program</parameter> whose indices are specified in the array of
            <parameter>uniformCount</parameter> unsigned integers <parameter>uniformIndices</parameter>. Upon success,
            the value of the parameter for each uniform is written into the corresponding entry in the array whose
            address is given in <parameter>params</parameter>. If an error is generated, nothing is written into
            <parameter>params</parameter>.
        </para>
        <para>
            If <parameter>pname</parameter> is <constant>GL_UNIFORM_TYPE</constant>, then an array identifying the types
            of uniforms specified by the corresponding array of <parameter>uniformIndices</parameter> is returned. The
            returned types can be any of the values from the following table:
        <informaltable>
            <tgroup cols="2" align="left">
                <colspec colwidth="1.1*"/>
                <colspec colwidth="1*"/>
                <thead>
                    <row>
                        <entry>
                            <emphasis role="bold"> Returned Symbolic Contant </emphasis>
                        </entry>
                            <entry><emphasis role="bold"> Shader Uniform Type </emphasis>
                        </entry>
                    </row>
                </thead>
                <tbody>
                    <row>
                        <entry>
                            <constant>GL_FLOAT</constant>
                        </entry>
                        <entry>
                            <constant>float</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_FLOAT_VEC2</constant>
                        </entry>
                        <entry>
                            <constant>vec2</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_FLOAT_VEC3</constant>
                        </entry>
                        <entry>
                            <constant>vec3</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_FLOAT_VEC4</constant>
                        </entry>
                        <entry>
                            <constant>vec4</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_INT</constant>
                        </entry>
                        <entry>
                            <constant>int</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_INT_VEC2</constant>
                        </entry>
                        <entry>
                            <constant>ivec2</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_INT_VEC3</constant>
                        </entry>
                        <entry>
                            <constant>ivec3</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_INT_VEC4</constant>
                        </entry>
                        <entry>
                            <constant>ivec4</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_UNSIGNED_INT</constant>
                        </entry>
                        <entry>
                            <constant>unsigned int</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_UNSIGNED_INT_VEC2</constant>
                        </entry>
                        <entry>
                            <constant>uvec2</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_UNSIGNED_INT_VEC3</constant>
                        </entry>
                        <entry>
                            <constant>uvec3</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_UNSIGNED_INT_VEC4</constant>
                        </entry>
                        <entry>
                            <constant>uvec4</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_BOOL</constant>
                        </entry>
                        <entry>
                            <constant>bool</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_BOOL_VEC2</constant>
                        </entry>
                        <entry>
                            <constant>bvec2</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_BOOL_VEC3</constant>
                        </entry>
                        <entry>
                            <constant>bvec3</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_BOOL_VEC4</constant>
                        </entry>
                        <entry>
                            <constant>bvec4</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_FLOAT_MAT2</constant>
                        </entry>
                        <entry>
                            <constant>mat2</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_FLOAT_MAT3</constant>
                        </entry>
                        <entry>
                            <constant>mat3</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_FLOAT_MAT4</constant>
                        </entry>
                        <entry>
                            <constant>mat4</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_FLOAT_MAT2x3</constant>
                        </entry>
                        <entry>
                            <constant>mat2x3</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_FLOAT_MAT2x4</constant>
                        </entry>
                        <entry>
                            <constant>mat2x4</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_FLOAT_MAT3x2</constant>
                        </entry>
                        <entry>
                            <constant>mat3x2</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_FLOAT_MAT3x4</constant>
                        </entry>
                        <entry>
                            <constant>mat3x4</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_FLOAT_MAT4x2</constant>
                        </entry>
                        <entry>
                            <constant>mat4x2</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_FLOAT_MAT4x3</constant>
                        </entry>
                        <entry>
                            <constant>mat4x3</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_SAMPLER_2D</constant>
                        </entry>
                        <entry>
                            <constant>sampler2D</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_SAMPLER_3D</constant>
                        </entry>
                        <entry>
                            <constant>sampler3D</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_SAMPLER_CUBE</constant>
                        </entry>
                        <entry>
                            <constant>samplerCube</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_SAMPLER_2D_SHADOW</constant>
                        </entry>
                        <entry>
                            <constant>sampler2DShadow</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_SAMPLER_2D_ARRAY</constant>
                        </entry>
                        <entry>
                            <constant>sampler2DArray</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_SAMPLER_2D_ARRAY_SHADOW</constant>
                        </entry>
                        <entry>
                            <constant>sampler2DArrayShadow</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_SAMPLER_CUBE_SHADOW</constant>
                        </entry>
                        <entry>
                            <constant>samplerCubeShadow</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_INT_SAMPLER_2D</constant>
                        </entry>
                        <entry>
                            <constant>isampler2D</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_INT_SAMPLER_3D</constant>
                        </entry>
                        <entry>
                            <constant>isampler3D</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_INT_SAMPLER_CUBE</constant>
                        </entry>
                        <entry>
                            <constant>isamplerCube</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_INT_SAMPLER_2D_ARRAY</constant>
                        </entry>
                        <entry>
                            <constant>isampler2DArray</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_UNSIGNED_INT_SAMPLER_2D</constant>
                        </entry>
                        <entry>
                            <constant>usampler2D</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_UNSIGNED_INT_SAMPLER_3D</constant>
                        </entry>
                        <entry>
                            <constant>usampler3D</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_UNSIGNED_INT_SAMPLER_CUBE</constant>
                        </entry>
                        <entry>
                            <constant>usamplerCube</constant>
                        </entry>
                    </row>
                    <row>
                        <entry>
                            <constant>GL_UNSIGNED_INT_SAMPLER_2D_ARRAY</constant>
                        </entry>
                        <entry>
                            <constant>usampler2DArray</constant>
                        </entry>
                    </row>
                </tbody>
            </tgroup>
        </informaltable>
        </para>
        <para>
            If <parameter>pname</parameter> is <constant>GL_UNIFORM_SIZE</constant>, then an array identifying the
            size of the uniforms specified by the corresponding array of <parameter>uniformIndices</parameter> is
            returned. The sizes returned are in units of the type returned by a query of <constant>GL_UNIFORM_TYPE</constant>.
            For active uniforms that are arrays, the size is the number of active elements in the array;
            for all other uniforms, the size is one.
        </para>
        <para>
            If <parameter>pname</parameter> is <constant>GL_UNIFORM_NAME_LENGTH</constant>, then an array identifying the
            length, including the terminating null character, of the uniform name strings specified by the corresponding
            array of <parameter>uniformIndices</parameter> is returned.
        </para>
        <para>
            If <parameter>pname</parameter> is <constant>GL_UNIFORM_BLOCK_INDEX</constant>, then an array identifying the
            the uniform block index of each of the uniforms specified by the corresponding array of <parameter>uniformIndices</parameter>
            is returned. The uniform block index of a uniform associated with the default uniform block is -1.
        </para>
        <para>
            If <parameter>pname</parameter> is <constant>GL_UNIFORM_OFFSET</constant>, then an array of uniform buffer
            offsets is returned. For uniforms in a named uniform block, the returned value will be its offset, in basic
            machine units, relative to the beginning of the uniform block in the buffer object data store. For uniforms
            in the default uniform block, -1 will be returned.
        </para>
        <para>
            If <parameter>pname</parameter> is <constant>GL_UNIFORM_ARRAY_STRIDE</constant>, then an array identifying the
            stride between elements, in basic machine units, of each of the uniforms specified by the corresponding array of
            <parameter>uniformIndices</parameter> is returned.  The stride of a uniform associated with the default uniform
            block is -1.  Note that this information only makes sense for uniforms that are arrays. For uniforms that are
            not arrays, but are declared in a named uniform block, an array stride of zero is returned.
        </para>
        <para>
            If <parameter>pname</parameter> is <constant>GL_UNIFORM_MATRIX_STRIDE</constant>, then an array identifying the stride
            between columns of a column-major matrix or rows of a row-major matrix, in basic machine units, of each of the uniforms
            specified by the corresponding array of <parameter>uniformIndices</parameter> is returned. The matrix stride of a
            uniform associated with the default uniform block is -1. Note that this information only makes sense for uniforms
            that are matrices. For uniforms that are not matrices, but are declared in a named uniform block, a matrix stride of
            zero is returned.
        </para>
        <para>
            If <parameter>pname</parameter> is <constant>GL_UNIFORM_IS_ROW_MAJOR</constant>, then an array identifying whether each
            of the uniforms specified by the corresponding array of <parameter>uniformIndices</parameter> is a row-major matrix or not is returned. A
            value of one indicates a row-major matrix, and a value of zero indicates a column-major matrix, a matrix in the default
            uniform block, or a non-matrix.
        </para>
    </refsect1>
    <refsect1 xml:id="errors"><title>Errors</title>
    <para><constant>GL_INVALID_VALUE</constant> is generated if
    <parameter>program</parameter> is not a value generated by
    OpenGL.</para>

    <para><constant>GL_INVALID_OPERATION</constant> is generated if
    <parameter>program</parameter> is not a program object.</para>

    <para><constant>GL_INVALID_VALUE</constant> is generated if
    <parameter>uniformCount</parameter> is greater than or equal to the
    value of <constant>GL_ACTIVE_UNIFORMS</constant> for
    <parameter>program</parameter>.</para>

    <para><constant>GL_INVALID_ENUM</constant> is generated if <parameter>pname</parameter>
    is not an accepted token.</para>
    </refsect1>
    <refsect1 xml:id="associatedgets"><title>Associated Gets</title>
    <para><citerefentry><refentrytitle>glGet</refentrytitle></citerefentry>
    with argument <constant>GL_MAX_VERTEX_UNIFORM_COMPONENTS</constant>,
    <constant>GL_MAX_FRAGMENT_UNIFORM_COMPONENTS</constant>, 
    <constant>GL_MAX_COMBINED_VERTEX_UNIFORM_COMPONENTS</constant>, or
    <constant>GL_MAX_COMBINED_FRAGMENT_UNIFORM_COMPONENTS</constant>.</para>

    <para><citerefentry><refentrytitle>glGetProgramiv</refentrytitle></citerefentry>
    with argument <constant>GL_ACTIVE_UNIFORMS</constant> or
    <constant>GL_ACTIVE_UNIFORM_MAX_LENGTH</constant>.</para>

    <para><citerefentry><refentrytitle>glIsProgram</refentrytitle></citerefentry></para>
    </refsect1>
    <refsect1 xml:id="versions">
        <title>API Version Support</title>
        <informaltable>
            <tgroup cols="3" align="left">
                <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="apifunchead.xml" xpointer="xpointer(/*/*)"/>
                <tbody>
                    <row>
                        <entry>glGetActiveUniformsiv</entry>
                        <xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="apiversion.xml" xpointer="xpointer(/*/*[@role='es20']/*)"/>
                    </row>
                </tbody>
            </tgroup>
        </informaltable>
    </refsect1>
    <refsect1 xml:id="seealso"><title>See Also</title>
    <para><citerefentry><refentrytitle>glGetUniform</refentrytitle></citerefentry>,
    <citerefentry><refentrytitle>glGetActiveUniform</refentrytitle></citerefentry>,
    <citerefentry><refentrytitle>glGetUniformLocation</refentrytitle></citerefentry>,
    <citerefentry><refentrytitle>glLinkProgram</refentrytitle></citerefentry>,
    <citerefentry><refentrytitle>glUniform</refentrytitle></citerefentry>,
    <citerefentry><refentrytitle>glUseProgram</refentrytitle></citerefentry></para>
    </refsect1>
    <refsect1 xml:id="Copyright"><title>Copyright</title>
        <para>
            Copyright <trademark class="copyright"/> 2003-2005 3Dlabs Inc. Ltd.
            Copyright <trademark class="copyright"/> 2010-2014 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>
