bool Batch::loadNormalData( GLfloat* normals, unsigned num_elements )
{
    // See commenting in loadPositionData

    if( m_NormalBuffer != 0 )
        glDeleteBuffers( 1, &m_NormalBuffer );

    if( m_VAO == 0 )
    {
        if( !genVAO( ) )
            return false;
    }

    if( m_NormalBuffer == 0 )
    {
        std::stringstream stream;
        stream << "Failed to generate m_NormalBuffer in batch '"
                << ( m_IDString.empty( ) ? "ID_NOT_SET" : m_IDString ) << "'";
        m_ErrorString = stream.str( );

        return false;
    }

    glBindVertexArray( m_VAO );
    glEnableVertexAttribArray( ToolBox::Math::GLSL_ATTR::NORMAL );
    glBindBuffer( GL_ARRAY_BUFFER, m_NormalBuffer );
    glBufferData( GL_ARRAY_BUFFER, sizeof( GLfloat ) * num_elements, normals, GL_STATIC_DRAW );
    glVertexAttribPointer( ToolBox::Math::GLSL_ATTR::NORMAL, 3, GL_FLOAT, GL_FALSE, 0, ( const GLvoid* )0 );
    glBindVertexArray( 0 );
    glBindBuffer( GL_ARRAY_BUFFER, 0 );

    return true;
}