
debugging
-----------------------------

  render.library provides a rather strict debugging strategy. the
  internal error manager looks like this:

	if (parameter_in_valid_range)
	{
		...
	}
	else
	{
		Exception_ILLEGAL();
		
		/* causing a $80000004 software failure */
	}

  it might appear strange at first sight, but this technique is very
  efficient. invalid parameters have got few chance to infiltrate
  the code and play havoc where it becomes really dangerous and hard
  to understand.

  the illegal exception (caused by an ILLEGAL opcode) is a 'clean'
  crash without further damage, and it can easily be catched with
  debuggers.

  so this exception might become your worst enemy when programming
  render.library. if you encounter dozens of $80000004 requesters
  and can't get rid of them, then it is very likely that the problem
  sits in front of your computer.

  this can easily drive you berzerk especially with
  DeleteRMHandler(). if DeleteRMHandler() crashes with an ILLEGAL
  exception, you know exactly that you forgot to free memory, or to
  delete a render.library instance such as palettes, histograms, or
  engines.

  this debugging concept is not provided with every function,
  though, but maybe i will apply it to more or even all functions in
  the future. it proved to be a very reliable error treatment, since
  it just cannot be ignored.
