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<?xml-stylesheet type="text/xsl" href="mathml.xsl"?><html xmlns="http://www.w3.org/1999/xhtml" xmlns:pref="http://www.w3.org/2002/Math/preference" pref:renderer="mathplayer-dl"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><link rel="stylesheet" type="text/css" href="opengl-man.css" /><title>glGetActiveUniformsiv - OpenGL 3.3 Reference Pages</title><meta name="generator" content="DocBook XSL Stylesheets V1.69.1" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glGetActiveUniformsiv"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glGetActiveUniformsiv — Returns information about several active uniform variables for the specified program object</p></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">glGetActiveUniformsiv</b>(</code></td><td>GLuint  </td><td><var class="pdparam">program</var>, </td></tr><tr><td> </td><td>GLsizei  </td><td><var class="pdparam">uniformCount</var>, </td></tr><tr><td> </td><td>const GLuint * </td><td><var class="pdparam">uniformIndices</var>, </td></tr><tr><td> </td><td>GLenum  </td><td><var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>GLint * </td><td><var class="pdparam">params</var><code>)</code>;</td></tr></table></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="parameters"></a><h2>Parameters</h2><div class="variablelist"><dl><dt><span class="term"><em class="parameter"><code>program</code></em></span></dt><dd><p>Specifies the program object to be queried.</p></dd><dt><span class="term"><em class="parameter"><code>uniformCount</code></em></span></dt><dd><p>Specifies both the number of elements in the array of indices <em class="parameter"><code>uniformIndices</code></em> and the
            number of parameters written to <em class="parameter"><code>params</code></em> upon successful return.</p></dd><dt><span class="term"><em class="parameter"><code>uniformIndices</code></em></span></dt><dd><p>Specifies the address of an array of <em class="parameter"><code>uniformCount</code></em> integers containing the indices of
            uniforms within <em class="parameter"><code>program</code></em> whose parameter <em class="parameter"><code>pname</code></em> pname.</p></dd><dt><span class="term"><em class="parameter"><code>pname</code></em></span></dt><dd><p>Specifies the property of the each uniform in <em class="parameter"><code>uniformIndices</code></em> that should be
            written into the corresponding element of <em class="parameter"><code>params</code></em>.</p></dd><dt><span class="term"><em class="parameter"><code>params</code></em></span></dt><dd><p>Specifies the address of an array of <em class="parameter"><code>uniformCount</code></em> integers which are to
            receive the value of <em class="parameter"><code>pname</code></em> for each uniform in <em class="parameter"><code>uniformIndices</code></em>.</p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
            <code class="function">glGetActiveUniformsiv</code> queries the value of the parameter named <em class="parameter"><code>pname</code></em>
            for each of the uniforms within <em class="parameter"><code>program</code></em> whose indices are specified in the array of
            <em class="parameter"><code>uniformCount</code></em> unsigned integers <em class="parameter"><code>uniformIndices</code></em>. Upon success,
            the value of the parameter for each uniform is written into the corresponding entry in the array whose
            address is given in <em class="parameter"><code>params</code></em>. If an error is generated, nothing is written into
            <em class="parameter"><code>params</code></em>.
        </p><p>
            If <em class="parameter"><code>pname</code></em> is <code class="constant">GL_UNIFORM_TYPE</code>, then an array identifying the types
            of uniforms specified by the corresponding array of <em class="parameter"><code>uniformIndices</code></em> is returned. The
            returned types can be any of the values from the following table:
        </p><div class="informaltable"><table border="1"><colgroup><col align="left" /><col align="left" /></colgroup><thead><tr><th align="left"><span class="bold"><strong>
                        Returned Symbolic Contant
                        </strong></span></th><th align="left"><span class="bold"><strong>
                        Shader Uniform Type
                        </strong></span></th></tr></thead><tbody><tr><td align="left">
                            <code class="constant">GL_FLOAT</code>
                        </td><td align="left">
                            <code class="constant">float</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_FLOAT_VEC2</code>
                        </td><td align="left">
                            <code class="constant">vec2</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_FLOAT_VEC3</code>
                        </td><td align="left">
                            <code class="constant">vec3</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_FLOAT_VEC4</code>
                        </td><td align="left">
                            <code class="constant">vec4</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_INT</code>
                        </td><td align="left">
                            <code class="constant">int</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_INT_VEC2</code>
                        </td><td align="left">
                            <code class="constant">ivec2</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_INT_VEC3</code>
                        </td><td align="left">
                            <code class="constant">ivec3</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_INT_VEC4</code>
                        </td><td align="left">
                            <code class="constant">ivec4</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_UNSIGNED_INT</code>
                        </td><td align="left">
                            <code class="constant">unsigned int</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_UNSIGNED_INT_VEC2</code>
                        </td><td align="left">
                            <code class="constant">uvec2</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_UNSIGNED_INT_VEC3</code>
                        </td><td align="left">
                            <code class="constant">uvec3</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_UNSIGNED_INT_VEC4</code>
                        </td><td align="left">
                            <code class="constant">uvec4</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_BOOL</code>
                        </td><td align="left">
                            <code class="constant">bool</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_BOOL_VEC2</code>
                        </td><td align="left">
                            <code class="constant">bvec2</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_BOOL_VEC3</code>
                        </td><td align="left">
                            <code class="constant">bvec3</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_BOOL_VEC4</code>
                        </td><td align="left">
                            <code class="constant">bvec4</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_FLOAT_MAT2</code>
                        </td><td align="left">
                            <code class="constant">mat2</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_FLOAT_MAT3</code>
                        </td><td align="left">
                            <code class="constant">mat3</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_FLOAT_MAT4</code>
                        </td><td align="left">
                            <code class="constant">mat4</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_FLOAT_MAT2x3</code>
                        </td><td align="left">
                            <code class="constant">mat2x3</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_FLOAT_MAT2x4</code>
                        </td><td align="left">
                            <code class="constant">mat2x4</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_FLOAT_MAT3x2</code>
                        </td><td align="left">
                            <code class="constant">mat3x2</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_FLOAT_MAT3x4</code>
                        </td><td align="left">
                            <code class="constant">mat3x4</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_FLOAT_MAT4x2</code>
                        </td><td align="left">
                            <code class="constant">mat4x2</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_FLOAT_MAT4x3</code>
                        </td><td align="left">
                            <code class="constant">mat4x3</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_SAMPLER_1D</code>
                        </td><td align="left">
                            <code class="constant">sampler1D</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_SAMPLER_2D</code>
                        </td><td align="left">
                            <code class="constant">sampler2D</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_SAMPLER_3D</code>
                        </td><td align="left">
                            <code class="constant">sampler3D</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_SAMPLER_CUBE</code>
                        </td><td align="left">
                            <code class="constant">samplerCube</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_SAMPLER_1D_SHADOW</code>
                        </td><td align="left">
                            <code class="constant">sampler1DShadow</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_SAMPLER_2D_SHADOW</code>
                        </td><td align="left">
                            <code class="constant">sampler2DShadow</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_SAMPLER_1D_ARRAY</code>
                        </td><td align="left">
                            <code class="constant">sampler1DArray</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_SAMPLER_2D_ARRAY</code>
                        </td><td align="left">
                            <code class="constant">sampler2DArray</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_SAMPLER_1D_ARRAY_SHADOW</code>
                        </td><td align="left">
                            <code class="constant">sampler1DArrayShadow</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_SAMPLER_2D_ARRAY_SHADOW</code>
                        </td><td align="left">
                            <code class="constant">sampler2DArrayShadow</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_SAMPLER_2D_MULTISAMPLE</code>
                        </td><td align="left">
                            <code class="constant">sampler2DMS</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_SAMPLER_2D_MULTISAMPLE_ARRAY</code>
                        </td><td align="left">
                            <code class="constant">sampler2DMSArray</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_SAMPLER_CUBE_SHADOW</code>
                        </td><td align="left">
                            <code class="constant">samplerCubeShadow</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_SAMPLER_BUFFER</code>
                        </td><td align="left">
                            <code class="constant">samplerBuffer</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_SAMPLER_2D_RECT</code>
                        </td><td align="left">
                            <code class="constant">sampler2DRect</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_SAMPLER_2D_RECT_SHADOW</code>
                        </td><td align="left">
                            <code class="constant">sampler2DRectShadow</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_INT_SAMPLER_1D</code>
                        </td><td align="left">
                            <code class="constant">isampler1D</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_INT_SAMPLER_2D</code>
                        </td><td align="left">
                            <code class="constant">isampler2D</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_INT_SAMPLER_3D</code>
                        </td><td align="left">
                            <code class="constant">isampler3D</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_INT_SAMPLER_CUBE</code>
                        </td><td align="left">
                            <code class="constant">isamplerCube</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_INT_SAMPLER_1D_ARRAY</code>
                        </td><td align="left">
                            <code class="constant">isampler1DArray</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_INT_SAMPLER_2D_ARRAY</code>
                        </td><td align="left">
                            <code class="constant">isampler2DArray</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_INT_SAMPLER_2D_MULTISAMPLE</code>
                        </td><td align="left">
                            <code class="constant">isampler2DMS</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_INT_SAMPLER_2D_MULTISAMPLE_ARRAY</code>
                        </td><td align="left">
                            <code class="constant">isampler2DMSArray</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_INT_SAMPLER_BUFFER</code>
                        </td><td align="left">
                            <code class="constant">isamplerBuffer</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_INT_SAMPLER_2D_RECT</code>
                        </td><td align="left">
                            <code class="constant">isampler2DRect</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_UNSIGNED_INT_SAMPLER_1D</code>
                        </td><td align="left">
                            <code class="constant">usampler1D</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_UNSIGNED_INT_SAMPLER_2D</code>
                        </td><td align="left">
                            <code class="constant">usampler2D</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_UNSIGNED_INT_SAMPLER_3D</code>
                        </td><td align="left">
                            <code class="constant">usampler3D</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_UNSIGNED_INT_SAMPLER_CUBE</code>
                        </td><td align="left">
                            <code class="constant">usamplerCube</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_UNSIGNED_INT_SAMPLER_1D_ARRAY</code>
                        </td><td align="left">
                            <code class="constant">usampler2DArray</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_UNSIGNED_INT_SAMPLER_2D_ARRAY</code>
                        </td><td align="left">
                            <code class="constant">usampler2DArray</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_UNSIGNED_INT_SAMPLER_2D_MULTISAMPLE</code>
                        </td><td align="left">
                            <code class="constant">usampler2DMS</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_UNSIGNED_INT_SAMPLER_2D_MULTISAMPLE_ARRAY</code>
                        </td><td align="left">
                            <code class="constant">usampler2DMSArray</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_UNSIGNED_INT_SAMPLER_BUFFER</code>
                        </td><td align="left">
                            <code class="constant">usamplerBuffer</code>
                        </td></tr><tr><td align="left">
                            <code class="constant">GL_UNSIGNED_INT_SAMPLER_2D_RECT</code>
                        </td><td align="left">
                            <code class="constant">usampler2DRect</code>
                        </td></tr></tbody></table></div><p>
        </p><p>
            If <em class="parameter"><code>pname</code></em> is <code class="constant">GL_UNIFORM_SIZE</code>, then an array identifying the
            size of the uniforms specified by the corresponding array of <em class="parameter"><code>uniformIndices</code></em> is
            returned. The sizes returned are in units of the type returned by a query of <code class="constant">GL_UNIFORM_TYPE</code>.
            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.
        </p><p>
            If <em class="parameter"><code>pname</code></em> is <code class="constant">GL_UNIFORM_NAME_LENGTH</code>, then an array identifying the
            length, including the terminating null character, of the uniform name strings specified by the corresponding
            array of <em class="parameter"><code>uniformIndices</code></em> is returned.
        </p><p>
            If <em class="parameter"><code>pname</code></em> is <code class="constant">GL_UNIFORM_BLOCK_INDEX</code>, then an array identifying the
            the uniform block index of each of the uniforms specified by the corresponding array of <em class="parameter"><code>uniformIndices</code></em>
            is returned. The uniform block index of a uniform associated with the default uniform block is -1.
        </p><p>
            If <em class="parameter"><code>pname</code></em> is <code class="constant">GL_UNIFORM_OFFSET</code>, 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.
        </p><p>
            If <em class="parameter"><code>pname</code></em> is <code class="constant">GL_UNIFORM_ARRAY_STRIDE</code>, then an array identifying the
            stride between elements, in basic machine units, of each of the uniforms specified by the corresponding array of
            <em class="parameter"><code>uniformIndices</code></em> 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.
        </p><p>
            If <em class="parameter"><code>pname</code></em> is <code class="constant">GL_UNIFORM_MATRIX_STRIDE</code>, 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 <em class="parameter"><code>uniformIndices</code></em> 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.
        </p><p>
            If <em class="parameter"><code>pname</code></em> is <code class="constant">GL_UNIFORM_IS_ROW_MAJOR</code>, then an array identifying whether each
            of the uniforms specified by the corresponding array of <em class="parameter"><code>uniformIndices</code></em> 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.
        </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p><code class="constant">GL_INVALID_VALUE</code> is generated if
    <em class="parameter"><code>program</code></em> is not a value generated by
    OpenGL.</p><p><code class="constant">GL_INVALID_OPERATION</code> is generated if
    <em class="parameter"><code>program</code></em> is not a program object.</p><p><code class="constant">GL_INVALID_VALUE</code> is generated if
    <em class="parameter"><code>uniformCount</code></em> is greater than or equal to the
    value of <code class="constant">GL_ACTIVE_UNIFORMS</code> for
    <em class="parameter"><code>program</code></em>.</p><p><code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>pname</code></em>
    is not an accepted token.</p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p><a href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a>
    with argument <code class="constant">GL_MAX_VERTEX_UNIFORM_COMPONENTS</code>,
    <code class="constant">GL_MAX_GEOMETRY_UNIFORM_COMPONENTS</code>,
    <code class="constant">GL_MAX_FRAGMENT_UNIFORM_COMPONENTS</code>,
    <code class="constant">GL_MAX_COMBINED_VERTEX_UNIFORM_COMPONENTS</code>,
    <code class="constant">GL_MAX_COMBINED_GEOMETRY_UNIFORM_COMPONENTS</code>,
    <code class="constant">GL_MAX_COMBINED_FRAGMENT_UNIFORM_COMPONENTS</code>.</p><p><a href="glGetProgram.xml"><span class="citerefentry"><span class="refentrytitle">glGetProgram</span></span></a>
    with argument <code class="constant">GL_ACTIVE_UNIFORMS</code> or
    <code class="constant">GL_ACTIVE_UNIFORM_MAX_LENGTH</code>.</p><p><a href="glIsProgram.xml"><span class="citerefentry"><span class="refentrytitle">glIsProgram</span></span></a></p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p><a href="glGetUniform.xml"><span class="citerefentry"><span class="refentrytitle">glGetUniform</span></span></a>,
    <a href="glGetActiveUniform.xml"><span class="citerefentry"><span class="refentrytitle">glGetActiveUniform</span></span></a>,
    <a href="glGetUniformLocation.xml"><span class="citerefentry"><span class="refentrytitle">glGetUniformLocation</span></span></a>,
    <a href="glLinkProgram.xml"><span class="citerefentry"><span class="refentrytitle">glLinkProgram</span></span></a>,
    <a href="glUniform.xml"><span class="citerefentry"><span class="refentrytitle">glUniform</span></span></a>,
    <a href="glUseProgram.xml"><span class="citerefentry"><span class="refentrytitle">glUseProgram</span></span></a></p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
            Copyright <span class="trademark"></span>© 2011 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.
            <a href="http://opencontent.org/openpub/" target="_top">http://opencontent.org/openpub/</a>.
        </p></div></div></body></html>
