[Openal-devel] Revisit Cygwin/OpenAL/OpenAL32 and Simgear Compile

[Jason Daly]

Brian Keener wrote:

>By using the --enable-debug-config option and recompiling and adding _alDebug 
>messages I have confirmed it does see my .openalrc in my $HOME directory in 
>Cygwin.  It does appear to parse it but yet the alc_device.c module on retuirn 
>from alParseConfig reports it was unable to parse the config file.  There is 
>something I am guessing at this point that is failing in buildExp or alEval 
>(this is where I think it is) or alEvalStr but still digging.
>
>A couple questions though - what is ALRC_CONSCELL - I see it is an enum but 
>what are the various meanings of it and the rest.  It seems to be assigned to 
>certain values in several structures and then used to search but not totally 
>sure of its meaning.
>  
>

I'm not sure.  I looked through it briefly and my best guess is that 
it's the type given to a list in the file (so the line (define devices 
'(esd sdl native wave null)) itself is an ALRC_CONSCELL, consisting of 
types ALRC_STRING, ALRC_STRING, and ALRC_CONSCELL.  This is just a 
guess, though.

>Also in al_config.c there is references in comments and in data structures to 
>setting the car and cdr sections/values - what is this - what is car/cdr and I 
>think there was one cadr.
>  
>

CAR and CDR are functions that come from LISP (a computer language for 
LISt Processing), which is the inspiration for the .openalrc file 
format.  The car of a list is the first item in the list and the cdr is 
everything after the first item.  So, in the list '(esd sdl native wave 
null), the car is esd and the cdr is '(sdl native wave null).

-- 

--"J"

"I'm a castaway stranded in a desolate land,
 I can see the footprints in the virtual sand."
	--Neil Peart