title: Where does glCopyTexImage2D save its pixels to?
body: <pre><code>Name
  glCopyTexImage2D — copy pixels into a 2D texture image
  
  C Specification
  void glCopyTexImage2D(GLenum  target,  GLint  level,  GLenum  internalformat,  GLint  x,  GLint  y,  GLsizei  width,  GLsizei  height,  GLint  border);
  </code></pre>
  
  <p>Apparently, the pixels must be stored somewhere, but where? The function returns void and does not use a pointer parameter.</p>
  
  <p>SO, where does glCopyTexImage2D save its pixels to?</p>