The falloff is the minimum distance at which inverse distance
attenuation takes place.
A non-positive value disables distance attenuation.
In the Lua API, nil can be used to disable attenuation, a boolean can be
used to enable attenuation with a default minimum distance, or a number
can be used for full control over the parameter.
Add support for importing ambisonic WAV files and 24/32 bit PCM WAV files.
The standard ambisonic format used internally in LÖVR is ACN channel ordering with SN3D normalization.
Anything else will be converted to this form.
There are a few restrictions and assumptions:
- Only 1st order ambisonics are supported. They need to have 4 channels.
- They can be in AMB format (Furse-Malham order/normalization), detected via WAVE_EXTENSIBLE GUID.
- Any other 4 channel file is assumed to be in "AmbiX" ACN/SN3D format.
- It seems that most ambisonic files in the wild that claim to be AmbiX are just 4 channel WAVs without any metadata.
- This means that non-ambisonic 4 channel WAVs could ambiguously be mistaken as ambisonic. This is incurred as a limitation of LÖVR.
- Ambisonic files can not currently be played back. SteamAudio currently has numerous bugs with this.
- Perhaps it would be possible to write an ambisonic rotator/panning decoder to use as a default implementation.
If 64 sources are playing and a new one is started, Source:play will
return false.
Instead of a linked list, a static list of 64 Sources is used.
Bit scanning intrinsics are used to efficiently iterate the list,
using a mask (still deciding on this).
- If no converter is needed, don't create/use it
- If no spatialization is needed, don't copy
In the best case, samples willi now be read into a buffer and immediately mixed into the output.
This is a large patch which adds a new Oculus Audio spatializer. Oculus Audio is slightly different from the dummy spatializer in a few ways:
- It *must* receive fixed-size input buffers, every time, always.
- It can only handle a fixed number of spatialized sound sources at a time.
- It has a concept of "tails"; the spatialization of a sound can continue after the sound itself ends (eg echo).
Changes to audio.c were needed to support Oculus Audio's quirks:
- audio.c now supports a "fixedBuffer" mode which invokes the generator/spatializer in fixed size chunks
- Each source now has an intptr_t "memo" field that the spatializer may use to store whatever (Oculus spatializer uses this to handle the sound source limit).
- The spatializer interface got a couple new methods: A "tail" method which returns a sound buffer after all sources are processed; and "create" and "destroy" methods that are called when a sound source is created or destroyed (Oculus spatializer uses this to populate/clear the "memo" field).
Along the way some other miscellaneous changes got made:
- lovr.audio.getSpatializerName() returns the current spatializer
- Spatializer init now takes in "config in" and "config out" structs (Spatializer changes fields in config out to request things, currently fixed buffer mode).
- lovr.conf now takes t.audio.spatializer (string name of desired spatializer) and t.audio.spatializerMaxSourcesHint (Spatializers with max sources limits like Oculus will use this as the limit).
- audio.c went back to tracking position/orientation as vectors rather than a matrix
- A file oculus_spatializer_math_shim.h was added containing a minimal copypaste of OVR_CAPI.h from Oculus SDK to support a ovrPoseStatef the spatializer API needs. This may have license consequences but we are probably OK via a combination of fair use and the fact that a user cannot use this header file without accepting Oculus's license through other means.
Some work remains to be done, in particular there is an entire reverb feature I did not touch and LOVR_USE_OCULUS_AUDIO cannot be activated from tup. Oculus Spatializer works better when it has velocity and time information but this patch does not supply it.
* Stop also uninitializes
* Reset doesn't exist. Just stop and start instead.
* lovrAudioInit no longer takes config, and config is now private.
Call lovrAudioStart if you want to start.
* ma_device_{un}init and start/stop are only called from one place each,
reducing the risk of dangling state
* Takes device type, so you only get either playback or capture devices
* Doesn't store devices in state, reducing risk of dangling pointers
* Uses names instead of identifiers, since miniaudio identifiers become
invalid if you call "getDevices" again
* Better diagnostics
* Split up lovrAudioInitDevice to be per-type, cleaner that way
* UseDevice now takes type and name, instead of just identifier
aka a9541579f38a0c1bab4bba294f3602fa0b80f127, plus cherry-pick of
2dc604ecde0f02280690c72f943bfb8bf52dd820.
There is a crasher in 0.10.13 and newer on Oculus Quest
(See https://github.com/mackron/miniaudio/issues/247)
