<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "xhtml1-transitional.dtd">
<!-- saved from url=(0013)about:internet -->
<?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>glGetVertexAttrib - OpenGL 4 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="glGetVertexAttrib"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glGetVertexAttrib — Return a generic vertex attribute parameter</p></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" style="padding-bottom: 1em"><tr><td><code class="funcdef">void <b class="fsfunc">glGetVertexAttribdv</b>(</code></td><td>GLuint  </td><td><var class="pdparam">index</var>, </td></tr><tr><td> </td><td>GLenum  </td><td><var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>GLdouble * </td><td><var class="pdparam">params</var><code>)</code>;</td></tr></table><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" style="padding-bottom: 1em"><tr><td><code class="funcdef">void <b class="fsfunc">glGetVertexAttribfv</b>(</code></td><td>GLuint  </td><td><var class="pdparam">index</var>, </td></tr><tr><td> </td><td>GLenum  </td><td><var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>GLfloat * </td><td><var class="pdparam">params</var><code>)</code>;</td></tr></table><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" style="padding-bottom: 1em"><tr><td><code class="funcdef">void <b class="fsfunc">glGetVertexAttribiv</b>(</code></td><td>GLuint  </td><td><var class="pdparam">index</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><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" style="padding-bottom: 1em"><tr><td><code class="funcdef">void <b class="fsfunc">glGetVertexAttribIiv</b>(</code></td><td>GLuint  </td><td><var class="pdparam">index</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><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" style="padding-bottom: 1em"><tr><td><code class="funcdef">void <b class="fsfunc">glGetVertexAttribIuiv</b>(</code></td><td>GLuint  </td><td><var class="pdparam">index</var>, </td></tr><tr><td> </td><td>GLenum  </td><td><var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>GLuint * </td><td><var class="pdparam">params</var><code>)</code>;</td></tr></table><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">glGetVertexAttribLdv</b>(</code></td><td>GLuint  </td><td><var class="pdparam">index</var>, </td></tr><tr><td> </td><td>GLenum  </td><td><var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>GLdouble * </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>index</code></em></span></dt><dd><p>Specifies the generic vertex attribute
            parameter to be queried.</p></dd><dt><span class="term"><em class="parameter"><code>pname</code></em></span></dt><dd><p>Specifies the symbolic name of the vertex
            attribute parameter to be queried. Accepted values are
            <code class="constant">GL_VERTEX_ATTRIB_ARRAY_BUFFER_BINDING</code>,
            <code class="constant">GL_VERTEX_ATTRIB_ARRAY_ENABLED</code>,
            <code class="constant">GL_VERTEX_ATTRIB_ARRAY_SIZE</code>,
            <code class="constant">GL_VERTEX_ATTRIB_ARRAY_STRIDE</code>,
            <code class="constant">GL_VERTEX_ATTRIB_ARRAY_TYPE</code>,
            <code class="constant">GL_VERTEX_ATTRIB_ARRAY_NORMALIZED</code>,
            <code class="constant">GL_VERTEX_ATTRIB_ARRAY_INTEGER</code>,
            <code class="constant">GL_VERTEX_ATTRIB_ARRAY_DIVISOR</code>, or
            <code class="constant">GL_CURRENT_VERTEX_ATTRIB</code>.</p></dd><dt><span class="term"><em class="parameter"><code>params</code></em></span></dt><dd><p>Returns the requested data.</p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p><code class="function">glGetVertexAttrib</code> returns in
    <em class="parameter"><code>params</code></em> the value of a generic vertex
    attribute parameter. The generic vertex attribute to be queried
    is specified by <em class="parameter"><code>index</code></em>, and the parameter
    to be queried is specified by <em class="parameter"><code>pname</code></em>.</p><p>The accepted parameter names are as follows:</p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_VERTEX_ATTRIB_ARRAY_BUFFER_BINDING</code></span></dt><dd><p>
                </p><p> <em class="parameter"><code>params</code></em> returns a
            single value, the name of the buffer object currently bound to
                    the binding point corresponding to generic vertex attribute array 
                    <em class="parameter"><code>index</code></em>. If no buffer object is bound, 
                    0 is returned. The initial value is 0.</p></dd><dt><span class="term"><code class="constant">GL_VERTEX_ATTRIB_ARRAY_ENABLED</code></span></dt><dd><p>
                </p><p> <em class="parameter"><code>params</code></em> returns a
            single value that is non-zero (true) if the vertex
            attribute array for <em class="parameter"><code>index</code></em> is
            enabled and 0 (false) if it is disabled. The initial
            value is <code class="constant">GL_FALSE</code>.</p></dd><dt><span class="term"><code class="constant">GL_VERTEX_ATTRIB_ARRAY_SIZE</code></span></dt><dd><p>
                </p><p> <em class="parameter"><code>params</code></em> returns a
            single value, the size of the vertex attribute array
            for <em class="parameter"><code>index</code></em>. 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.</p></dd><dt><span class="term"><code class="constant">GL_VERTEX_ATTRIB_ARRAY_STRIDE</code></span></dt><dd><p>
                </p><p> <em class="parameter"><code>params</code></em> returns a
            single value, the array stride for (number of bytes
            between successive elements in) the vertex attribute
            array for <em class="parameter"><code>index</code></em>. A value of 0
            indicates that the array elements are stored
            sequentially in memory. The initial value is 0.</p></dd><dt><span class="term"><code class="constant">GL_VERTEX_ATTRIB_ARRAY_TYPE</code></span></dt><dd><p>
                </p><p> <em class="parameter"><code>params</code></em> returns a
            single value, a symbolic constant indicating the
            array type for the vertex attribute array for
            <em class="parameter"><code>index</code></em>. Possible values are
            <code class="constant">GL_BYTE</code>,
            <code class="constant">GL_UNSIGNED_BYTE</code>,
            <code class="constant">GL_SHORT</code>,
            <code class="constant">GL_UNSIGNED_SHORT</code>,
            <code class="constant">GL_INT</code>,
            <code class="constant">GL_UNSIGNED_INT</code>,
            <code class="constant">GL_FLOAT</code>, and
            <code class="constant">GL_DOUBLE</code>. The initial value is
            <code class="constant">GL_FLOAT</code>.</p></dd><dt><span class="term"><code class="constant">GL_VERTEX_ATTRIB_ARRAY_NORMALIZED</code></span></dt><dd><p>
                </p><p> <em class="parameter"><code>params</code></em> returns a
            single value that is non-zero (true) if fixed-point
            data types for the vertex attribute array indicated
            by <em class="parameter"><code>index</code></em> are normalized when
            they are converted to floating point, and 0 (false)
            otherwise. The initial value is
            <code class="constant">GL_FALSE</code>.</p></dd><dt><span class="term"><code class="constant">GL_VERTEX_ATTRIB_ARRAY_INTEGER</code></span></dt><dd><p>
                </p><p> <em class="parameter"><code>params</code></em> returns a
            single value that is non-zero (true) if fixed-point
            data types for the vertex attribute array indicated
            by <em class="parameter"><code>index</code></em> have integer data types, and 0 (false)
            otherwise. The initial value is
            0 (<code class="constant">GL_FALSE</code>).</p></dd><dt><span class="term"><code class="constant">GL_VERTEX_ATTRIB_ARRAY_DIVISOR</code></span></dt><dd><p>
                </p><p> <em class="parameter"><code>params</code></em> returns a
            single value that is the frequency divisor used for instanced
            rendering. See <a href="glVertexAttribDivisor.xml"><span class="citerefentry"><span class="refentrytitle">glVertexAttribDivisor</span></span></a>.
            The initial value is 0.</p></dd><dt><span class="term"><code class="constant">GL_CURRENT_VERTEX_ATTRIB</code></span></dt><dd><p>
                </p><p> <em class="parameter"><code>params</code></em> returns four
            values that represent the current value for the
            generic vertex attribute specified by index. Generic
            vertex attribute 0 is unique in that it has no
            current state, so an error will be generated if
            <em class="parameter"><code>index</code></em> is 0. The initial value
            for all other generic vertex attributes is
            (0,0,0,1).</p><p>
                <code class="function">glGetVertexAttribdv</code> and <code class="function">glGetVertexAttribfv</code>
                return the current attribute values as four single-precision floating-point values;
                <code class="function">glGetVertexAttribiv</code> reads them as floating-point values and
                converts them to four integer values; <code class="function">glGetVertexAttribIiv</code> and
                <code class="function">glGetVertexAttribIuiv</code> read and return them as signed or unsigned
                integer values, respectively; <code class="function">glGetVertexAttribLdv</code> reads and returns
                them as four double-precision floating-point values.
            </p></dd></dl></div><p>All of the parameters except <code class="constant">GL_CURRENT_VERTEX_ATTRIB</code>
    represent state stored in the currently bound vertex array object.</p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>If an error is generated, no change is made to the
    contents of <em class="parameter"><code>params</code></em>.</p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p><code class="constant">GL_INVALID_OPERATION</code> is generated if <em class="parameter"><code>pname</code></em>
    is not <code class="constant">GL_CURRENT_VERTEX_ATTRIB</code> and there is no
    currently bound vertex array object.</p><p><code class="constant">GL_INVALID_VALUE</code> is generated if
    <em class="parameter"><code>index</code></em> is greater than or equal to
    <code class="constant">GL_MAX_VERTEX_ATTRIBS</code>.</p><p><code class="constant">GL_INVALID_ENUM</code> is generated if
    <em class="parameter"><code>pname</code></em> is not an accepted value.</p><p><code class="constant">GL_INVALID_OPERATION</code> is generated if
    <em class="parameter"><code>index</code></em> is 0 and
    <em class="parameter"><code>pname</code></em> is
    <code class="constant">GL_CURRENT_VERTEX_ATTRIB</code>.</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_ATTRIBS</code></p><p><a href="glGetVertexAttribPointerv.xml"><span class="citerefentry"><span class="refentrytitle">glGetVertexAttribPointerv</span></span></a>
    with arguments <em class="parameter"><code>index</code></em> and
    <code class="constant">GL_VERTEX_ATTRIB_ARRAY_POINTER</code></p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p><a href="glBindAttribLocation.xml"><span class="citerefentry"><span class="refentrytitle">glBindAttribLocation</span></span></a>,
    <a href="glBindBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glBindBuffer</span></span></a>,
    <a href="glDisableVertexAttribArray.xml"><span class="citerefentry"><span class="refentrytitle">glDisableVertexAttribArray</span></span></a>,
    <a href="glEnableVertexAttribArray.xml"><span class="citerefentry"><span class="refentrytitle">glEnableVertexAttribArray</span></span></a>,
    <a href="glVertexAttrib.xml"><span class="citerefentry"><span class="refentrytitle">glVertexAttrib</span></span></a>,
    <a href="glVertexAttribDivisor.xml"><span class="citerefentry"><span class="refentrytitle">glVertexAttribDivisor</span></span></a>,
    <a href="glVertexAttribPointer.xml"><span class="citerefentry"><span class="refentrytitle">glVertexAttribPointer</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>© 2003-2005 3Dlabs Inc. Ltd. 
            Copyright <span class="trademark"></span>© 2010 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>
