[Radiance-general] FYI Re: CVS, ANSI

[Greg Ward]

I agree that a code rewrite would be nice, but would require way more 
free time than I have, and I'm not sure I'd trust the task to someone 
else.  Making Radiance ANSI-C compatible, at least as far as adding 
function prototypes and the like, wouldn't be terribly difficult, and is 
probably a recommended first step to having others working on the code 
base.  I only wish I were more familiar with what's in ANSI-C and what's 
not.

There are two reasons Radiance wasn't converted to ANSI-C long ago.  
First, some systems (Sun in particular) were distributed with a free K&R 
compiler, but you had to pay for the ANSI-C compiler, so many people 
couldn't have built Radiance if it were ANSI-C.  Second, I had a bias 
against ANSI-C because I never ran into portability problems before its 
invention, but had nothing but trouble afterwards.  From my perspective, 
ANSI-C was a giant step backwards in compatibility, with a subsequent 
explosion of header files and prototypes and subtle system differences.  
Before ANSI, I could hop onto virtually any machine and read the header 
files to know what was going on.  After ANSI and the related attempts to 
"standardize" UNIX, I couldn't make sense of any of the headers anymore, 
since there were about a dozen #ifdef's in each one for all the various 
attempted compatibilities.

If I were to really rewrite Radiance, I would want to start from the 
ground up and take a different approach to many problems.  The process 
might take years, and it's by no means certain that the final result 
would be any better than what we currently have.  Furthermore, who would 
fund such a development effort?  It was a brutal struggle to do it in 
the first place within all the budget constraints at LBNL, and what 
little money there was for research software development there and 
elsewhere in the U.S. has all but dried up.

I solved Len's compile problems by jumping onto his machine and making a 
few changes.  Besides the sys_errlist definition, there were a couple of 
other things that were messed up due to the combination of GNU-C and 
Solaris.  That's a good idea to use strerror(), though -- I'll put that 
into the next release.  I embarrassed to say that I didn't know about it.

-Greg