         <code class="constant">GL_INVALID_OPERATION</code> is generated if a non-zero buffer object name is bound to the
            <code class="constant">GL_PIXEL_UNPACK_BUFFER</code> target and the data would be unpacked from the buffer
            object such that the memory reads required would exceed the data store size.
        </p><p>
            Undefined results, including abnormal program termination, are generated if
            <em class="parameter"><code>data</code></em> is not encoded in a m