Request for method to deterimine which host-API specific extensions are installed (at compile time & runtime)

[rossb]

see thread: http://techweb.rfa.org/pipermail/portaudio/2007-July/007320.html

In summary: 1. People want a way to detect which host APIs are available when compiling PA 2. People want a way to detect which host APIs are compiled-in at runtime 3. People want a way to look up function-pointers for host-API extensions

These are in part separate issues.

Issue 1 is related to the configuration (how PA is built/configured). As noted below we would need to agree on some standard preprocessor symbols, and then they would need to be used on different platforms.

It has been noted that 2 can be addressed by changing the specification such that all compiled-in host APIs are always reported by PA, even those with no devices, or who returned an error during initialization.

Issue 3 can be handled in a number of different ways... possibly without the help of PortAudio if issues 1 and 2 are resolved.

Arve wrote: Tim Blechmann made a valid point regarding the use of host-API specific PortAudio extensions: These should be exposed to client code in some standard manner. He maintains we should install these headers in a "portaudio" directory, (e.g. include/portaudio), and then advertise which are available through macros such as PA_HAVE_JACK (or PA_USE_JACK?) etc in a generated header portaudio/config.h. He also suggested that these headers be automatically included via portaudio.h when available, but I'm unsure whether convention dictates to let the client include such headers himself (depending on PA_HAVE_* macros).