Based on DirectSound's EAX behavior, committing any EAX property commits *all*
deferred property changes, not just the object being changed. So applying EAX
changes can be handled in one place.
Specifically, AL_[EAX]REVERB_ROOM_ROLLOFF_FACTOR always applies to an inverse
distance rolloff model, where the source's AL_ROOM_ROLLOFF_FACTOR applies to
the selected distance model. Consequently, the normal distance and cone
attenuation only needs to be calculated once for all sends, with the effect's
room rolloff calculated and applied separately.
The idea here is that the initial reverb decay can't become less than the dry
path distance attenuation, as the dry attenuation represents the audio that has
not yet had a chance to start reflecting in the environment. As well, the
reference distance indicates where there is no distance attenuation, with any
initial attenuation set by the environment itself.
So what we do is use the dry path attenuation as the baseline for what's mixed
to the reverb, with the decay rate indicating how much of the remaining room
(non-direct) energy attenuates with distance.
This may be over-complicating it. Other sources hint at a more typical XdB per
doubling of distance, with X varying depending on environment properties (room
size, absorbancy, etc). This could be handled by applying a normal inverse
distance attenuation model, with a rolloff factor generated from the reverb
properties (density, decay rate, etc). Will need more testing and research.
It was only added to try to help DSOAL, and it's not clear if it's even
necessary. But with native EAX API support, it certainly isn't necessary
anymore.
I'll assume for now that the limits for the EAX properties will keep the filter
gain from getting out of hand. The filter's gainhf is relative to the gain and
is limited to 0dB max.
The standard says a function being returned doesn't necessarily mean it's
usable, and calling them will return failure if called when not usable. The
config option still prevents it from being returned, to better hide it when
disabled globally.
* [EAX] Fix effect GUID validation
Only NULL and REVERB was valid.
* [EAX] Fix default FX slot flags
EAX4 and EAX5 both sets to ENVIRONMENT.
* [EAX] Set default values for legacy FX slots in the initialization
* [EAX] Fix FX slot locking policy
Fail on attempt to load an effect or change a lock for EAX4 "set" call.
Unlock legacy FX slots on any EAX5 call.
* [EAX] Allow DEFER flag for "get" calls.
* [EAX] Make speaker configuration read-only
* [EAX] Initialize speaker configuration
* [EAX] Commit EAX source on a 3D source parameter call
Reference: EAX 4.0 Programmer's Guide
* [EAX] Commit EAX source on a 3D listener parameter call
Reference: EAX 4.0 Programmer's Guide
* [EAX] Commit source when it begins to play
Reference: EAX 4.0 Programmer's Guide
* Add EAX extensions (EAX 2.0-5.0, X-RAM)
* Comment out C++17 leftovers
* Remove everything related to patching
* Update alsoftrc.sample
* Rewrite integration
* Fix GCC compilation under Linux
* Always reset EAX effect properties when loading it into FX slot
