[openal] ALC_SOFT_HRTF proposal

[Chris Robinson]

On 05/17/2015 04:09 AM, Victorious wrote:
> This looks pretty neat. Are these options available in the latest
> version in the repository, or is this just a draft specification at
> this stage?

It's in the latest version in the repo, however all the macros and stuff 
are in the private alMain.h header as it's still all subject to change. 
Feel free to copy it out and play around with using them, just don't 
keep them in production code since the final version that gets put into 
alext.h with the next release may have incompatible changes.

> Also, why not just have 2 states, on/off defaulted to off? The
> defaults, if Ian's report is any indication, don't work well even if
> headphones are present as they don't get detected properly.

Whether or not headphones get detected depends on a couple factors. 
Standard headphones with a typical 3.5mm plug will generally not be 
detected, since analog speaker devices were unfortunately not designed 
with the ability to report such info back to its host. But detection can 
sometimes work, for instance with USB headphones or if the device was so 
configured at the OS/sound system level. Even if it's a rare occurrence, 
if some devices are able to say "yeah, I'm headphones" I think it'd be 
preferable for HRTF to Just Work on those devices without needing user 
interaction.