It isn't always correct once you add locomotion to a project, and
it actually becomes harmful because the pose ping-pongs between
the default pose and the user pose, causing distortion.
- 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.