title: When Should One Call glGetError?
body: <p><a href="http://www.opengl.org/sdk/docs/man/xhtml/glLoadIdentity.xml" rel="noreferrer">glLoadIdentity</a> says </p>
  
  <blockquote>
    <p><code>GL_INVALID_OPERATION</code> is generated if
    <code>glLoadIdentity</code> is executed between the
    execution of <code>glBegin</code> and the
    corresponding execution of <code>glEnd</code>.</p>
  </blockquote>
  
  <p>But <code>GL_INVALID_OPERATION</code> is a flag returns by <a href="http://msdn.microsoft.com/en-us/library/dd373546(VS.85).aspx" rel="noreferrer">glGetError</a>.</p>
  
  <p>My question is, when should we call <code>glGetError</code> ( in order to know whether we are calling opengl in correct sequence)? </p>