This tends to be a frequent spot where drivers hang, and the waits were
often unreliable in any case.
Instead, our audio thread now alerts the driver that we're done streaming audio
(which currently XAudio2 uses to alert the system not to warn about the
impending underflow) and then SDL_Delay()'s for a duration that's reasonable
to drain the DMA buffers before closing the device.
This tries to make SDL robust against device drivers that have hung up,
apps don't freeze in catastrophic (but not necessarily uncommon) conditions.
Now we detach the audio thread and let it clean up and don't care if it
never actually runs to completion.
James Zipperer
The problem I was seeing was that the the ALSA hotplug thread would call SDL_RemoveAudioDevice, but my application code was not seeing an SDL_AUDIODEVICEREMOVED event to go along with it. To fix it, I added some code into SDL_RemoveAudioDevice to call SDL_OpenedAudioDeviceDisconnected on the corresponding open audio device. There didn't appear to be a way to cross reference the handle that SDL_RemoveAudioDevice gets and the SDL_AudioDevice pointer that SDL_OpenedAudioDeviceDisconnected needs, so I ended up adding a void *handle field to struct SDL_AudioDevice so that I could do the cross reference.
Is there some other way beside adding a void *handle field to the struct to get the proper information for SDL_OpenedAudioDeviceDisconnected?
James Zipperer
Close the audio device before waiting for the audio thread to complete, which fixes a situation where the audio thread never completes
Add an additional check in the audio thread to see if the device is enabled and bail out if the device is no longer enabled
The Apple TV remote is currently exposed as a joystick with its touch surface treated as two axes. Key presses are also generated when its buttons and touch surface are used.
A new hint has been added to help deal with deciding whether to background the app when the remote's menu button is pressed: SDL_HINT_APPLE_TV_CONTROLLER_UI_EVENTS.
AudioQueues are available in Mac OS X 10.5 and later (and iOS 2.0 and later).
Their API is much more clear (and if you don't mind the threading tapdance
to get its own CFRunLoop) much easier to use in general for our purposes.
As an added benefit: they seemlessly deal with format conversion in ways
AudioUnits don't: for example, my MacBook Pro's built-in microphone won't
capture at 8000Hz and the AudioUnit version wouldn't resample to hide this
fact; the AudioQueue version, however, can handle this.
Moved this code from winmm into core so both can use it.
DirectSound (at least on Win10) also returns truncated device names, even
though it's handed in as a string pointer and not a static-sized buffer. :/
Otherwise, if you had a massive, one-time queue buildup, the memory from that
remains allocated until you close the device. Also, if you are just using a
reasonable amount of space, this would previously cause you to reallocate it
over and over instead of keeping a little bit of memory around.
I think this was important for SDL 1.2 because some targets needed
special device memory for DMA buffers or locked memory buffers for use in
hardware interrupts or something, but since it just defines to SDL_malloc
and SDL_free now, I took it out for clarity's sake.
- It's now always called if device->hidden isn't NULL, even if OpenDevice()
failed halfway through. This lets implementation code not have to clean up
itself on every possible failure point; just return an error and SDL will
handle it for you.
- Implementations can assume this->hidden != NULL and not check for it.
- implementations don't have to set this->hidden = NULL when done, because
the caller is always about to free(this).
- Don't reset other fields that are in a block of memory about to be free()'d.
- Implementations all now free things like internal mix buffers last, after
closing devices and such, to guarantee they definitely aren't in use anymore
at the point of deallocation.
Turns out that libartsc isn't thread-safe, so if we run a capture and playback
device at the same time, it often crashes in arts's internal event loop.
We could throw mutexes around the read/write calls, but these are meant to
block, so one device could cause serious latency and stutter in the other.
Since this audio target isn't in high-demand (Ubuntu hasn't offered a libartsc
package for years), I'm just backing out the capture support. If someone needs
it, they can pull it out of the revision history.
(We probably never noticed because this is meant to block until it fully
writes a buffer, and would only trigger an issue if we had a short write
that wasn't otherwise an error condition.)
This allows us to set an explicit stack size (overriding the system default
and the global hint an app might have set), and remove all the macro salsa
for dealing with _beginthreadex and such, as internal threads always set those
to NULL anyhow.
I've taken some guesses on reasonable (and tiny!) stack sizes for our
internal threads, but some of these might turn out to be too small in
practice and need an increase. Most of them are simple functions, though.
This is kind of nasty, because ALSA reports dozens of "devices" that aren't
really things you'd ever want, or things that should be listed this way, but
the default path still works as before, and it at least allows these devices
to be available to apps.
This does not handle hotplugging yet. You get a device list at init time
and that's it.
xaudio2 is not linked against sdl but the sdk already handles dynamically loading (XAudio2Create is inlined and just loads a com object). Updated SDL_xaudio2.c
"UWP" appears to be Microsoft's new name for WinRT/Windows-Store APIs.
This set of changes updates SDL's WinRT backends to support the Win10 flavor
of WinRT. It has been tested on Win10 on a desktop. In theory, it should
also support Win10 on other devices (phone, Xbox One, etc.), however further
patches may be necessary.
This adds:
- a set of MSVC 2015 project files, for use in creating UWP apps
- modifications to various pieces of SDL, in order to compile via MSVC 2015 +
the Win10 API set
- enables SDL_Window resizing and programmatic-fullscreen toggling, when using
the WinRT backend
- WinRT README updates
- disable compiling in XAudio2 support. We both need the DX SDK to make this code plus we need to work out the runtime dependency problem this code bring in on windows (needing the DX runtime installed).
CR: SamL
The internal function SDL_EGL_LoadLibrary() did not delete and remove a mostly
uninitialized data structure if loading the library first failed. A later try to
use EGL then skipped initialization and assumed it was previously successful
because the data structure now already existed. This led to at least one crash
in the internal function SDL_EGL_ChooseConfig() because a NULL pointer was
dereferenced to make a call to eglBindAPI().
