This is the one that splits the "left wing" into two for loops to
bubble out the conditional that decides if it should read from the
left padding or the input buffer.
I still believe the optimization is good, but the basic logic of it
was incorrect, and needs to be reexamined and fixed before going
back into revision control.
We can get _some_ of the info we need out of standard Xlib and report a
single display (which might actually be multiple physical displays mushed
into a single desktop). This is better than nothing, but you should really
just build with XRandR support and get a better X server. :)
- Calculate `j * RESAMPLER_SAMPLES_PER_ZERO_CROSSING` once per loop
iteration since we use it multiple times.
- Do the left-wing loop in two sections: while `srcframe < 0` and then
the remaining calculations when `srcframe >= 0`. This bubbles a conditional
out of every iteration of a tight loop, giving us a boost. We could
_probably_ do this to the right-wing loop too, but it's less straightforward
there.
- The real win: Use floats instead of doubles. This almost doubles the speed
of the entire function on Intel CPUs, and for embedded things without
hardware-level support for doubles, the speedup is enormous. This in
theory might reduce audio quality, though, and I had to put a check in
place to avoid a division-by-zero that we avoided at higher precision, but
this is likely to be worth keeping for at least the Sony PSP and other
smaller platforms, if not everyone.
Instead of waiting until the entire buffer from the SDL callback is ready
to be accepted by PulseAudio, we use pa_stream_set_write_callback and
feed some portion of the buffer as callbacks come in asking for more.
This lets us remove the halving of the buffer size during device open,
and also (hopefully) solves several strange hangs that happen in unusual
circumstances.
Fixes#4387Fixes#2262
* Read IMU scale data from Switch controllers. Up until now, SDL has used hard-coded scaling which isn't correct with some supported controllers.
* Moved declarations to beginning of code blocks to better fit with SDL style requirements
Every other backend does this, so this should match, now.
It's possible this was harmless, but we can avoid the system call
and the (likely?) debug message when it fails, though!
Ryan C. Gordon
Eddy Jansson
Ozkan Sezer
Sam Lantinga
Mirko Galimberti
FriendlyAI
Jibb Smart
Dimitriy Ryazantcev
Mathieu Eyraud
meyraud705
Cameron Gutman
Frank Praznik