[CMake] #cmakedefine and the #if vs #ifdef argument

[Hostile Fork]

Hello list!

As a learning exercise, I am adding CMake and CTest to a small open- 
source library I made which currently has no build system:

	http://hostilefork.com/nstate/
	http://hostilefork.com/nocycle/

For the first step, I have been applying the "configure_file"  
methodology to this header:

	http://github.com/hostilefork/nocycle/blob/1ac238aea7af9e02f3a49f0c7eb991074c8eb3fd/NocycleSettings.hpp

( Following these directions: http://www.vtk.org/Wiki/CMake_HowToDoPlatformChecks 
  )

It seems the #cmakedefine lines are replaced with one of these two  
cases:

	#define VAR_THAT_IS_ON
	/* #undef VAR_THAT_IS_OFF */

However... in the past I have been persuaded by the argument that the  
use of #if is superior to #ifdef for conditional compilation.   
( Roddy's comment here on StackOverflow summarizes the advantages  
pretty well: http://stackoverflow.com/questions/135069/ifdef-vs-if-which-is-bettersafer 
  )

Is it possible to get CMake to produce something more like:

	#define VAR_THAT_IS_ON 1
	#define VAR_THAT_IS_OFF 0

There are other questions I have lined up.  :)  But I'll start with  
just that one, and if anyone wants to be proactive offer advice/ 
pointers/urls based on the existing source... please jump in!

Thanks!
---Brian