of
	<code class="constant">NULL</code> can be passed in the
	<em class="parameter"><code>length</code></em> argument.</p><p>The <em class="parameter"><code>type</code></em> argument will return a
	pointer to the attribute variable's data type. The symbolic
	constants <code class="constant">GL_FLOAT</code>,
	<code class="constant">GL_FLOAT_VEC2</code>,
	<code class="constant">GL_FLOAT_VEC3</code>,
	<code class="constant">GL_FLOAT_VEC4</code>,
	<code class="constant">GL_FLOAT_MAT2</code>,
	<code class="consta