Anthony Pesch's notes on his patch:
"Currently, the WASAPI backend creates a stream in shared mode and sets the
device's callback size to be half of the shared stream's total buffer size.
This works, but doesn't coordinate will with the actual hardware. The hardware
will raise an interrupt after every period which in turn will signal the
object being waited on inside of WaitDevice. From my empirical testing, the
callback size was often larger than the period size and not a multiple of it,
which resulted in poor latency when trying to time an application based on the
audio callback. The reason for this looked something like:
* The device's callback would be called and and the audio buffer was filled.
* WaitDevice would be called.
* The hardware would raise an interrupt after one period.
* WaitDevice would resume, see that a a full callback had not been played and
then wait again.
* The hardware would raise an interrupt after another period.
* WaitDevice would resume, see that a full callback + some extra amount had
been played and then it would again call our callback and this process would
repeat.
The effect of this is that the pacing between subsequent callbacks is poor -
sometimes it's called very quickly, sometimes it's called very late.
By matching the callback's size to the stream's period size, the pacing of
calls to the user callback is improved substantially. I didn't write an actual
test for this, but my use case for this was my Dreamcast emulator
(https://redream.io) which uses the audio callback to help drive the emulation
speed. Without this change and with the default shared stream buffer (which
has a period of ~10ms) I would get frame times that were between ~3-30
milliseconds; after this change I get frame times of ~11-22 milliseconds.
Note, this patch also has a change that removes passing a duration to the
Initialize call. It seems that the default duration used (when 0 is passed)
does typically match up with the duration returned by GetDevicePeriod, however
the Initialize docs say:
> To set the buffer to the minimum size required by the engine thread, the
> client should call Initialize with the hnsBufferDuration parameter set to 0.
> Following the Initialize call, the client can get the size of the resulting
> buffer by calling IAudioClient::GetBufferSize.
This change isn't strictly required, but I made it to hopefully rule out
another source of unexpected latency."
Fixes Bugzilla #4592.
If called from background threads, use Grand Central Dispatch to use the
main thread instead. On the main thread, just call them directly.
Fixes Bugzilla #4932.
Apparently, recent versions of autotools will issue an error if an empty
description is supplied to AC_DEFINE(). Avoid these errors by just
adding a space in the square brackets.
Partially fixes Bugzilla #4908.
The warnings were produced by GCC 9.2.x for x86_64-linux-gnu or
i386-pc-msdosdjgpp targets.
Most of the fixes involve changing the type of a variable rather than
the format specifier. For many of the affected test conuter variables,
a basic int seems sufficient.
Some format specifier warnings still remain for cases where changing
type or casting seemed inappropriate. Those warnings will probably
require some new format specifier macros (e.g. SDL_PRIu32).
Jason
In iOS, URL Events trigger the DropFile event. I would also expect the same event to be fired on the macOS platform but this is not implemented at all in the AppDelegate.
Konrad
It appears that I cannot use SDL_RenderReadPixels on a bound framebuffer (SDL_Texture set as render target) as it simply results in gibberish data. However, drawing that framebuffer into the default target (window surface) does render it correctly. Other backends (OpenGL, software, Direct3D) do work fine.
It looks to me like D3D11_RenderReadPixels just gets the general backbuffer and not the current render target and its backbuffer.
Here is the patch which actually fetches the current render target and its underlying ID3D11Resource which is ID3D11Texture2D.
DominikD
There are several tests that need resources in the output directory to work:
* `testiconv` depends on `utf8.txt`
* `testoverlay2` and `teststreaming` depend on `moose.dat`
This patch adds these two files to the `RESOURCE_FILES` variable.
One could also copy `shapes\*.bmp` over to the output directory for `testshape` to use but this patch doesn't do that for three reasons:
* executable takes path as an argument and doesn't need these files side by side
* these are ~45MB and copying them over would cause build directory to swell
* there are already files in the output directory that can be used with this test (`sample.bmp` and `button.bmp`)
There are multiple SDL APIs that internally sink into dbus calls, e.g. battery
status, thread priority. If those calls happen in different threads simultaneously
it can result in dbus crashes.
To abide by dbus's multithreading guidelines we must call dbus_threads_init_default()
to enable dbus's internal locking mechanisms:
https://dbus.freedesktop.org/doc/api/html/group__DBusThreads.html#gac7b8a7001befc3eaa8c6b043151008dc
Additionally, access to a DBusMessage must be synchronized between threads.
SDL was already abiding that guideline as the DBusMessage structs aren't shared.
The following email from the dbus mailing list hints that arbitrating access to
the DBusConnection on the SDL may also be required:
https://lists.freedesktop.org/archives/dbus/2017-September/017306.html
Currently the message is double terminated, which results in SDL_DBus_CallMethodInternal()
incorrectly assuming that the other party is always returning true.
I'm not super familiar with dbus, so I'm not sure if this could also be the cause of this bug:
https://github.com/ValveSoftware/steam-for-linux/issues/6901
So if you go into System Preferences on a MacBook and toggle between a pair of
connected bluetooth headphones and built-in internal speakers, SDL will
switch the device it is playing sound through, to match this setting, on the
fly.
Likewise if the default output device is a USB thing and is unplugged; as the
default device changes at the system level, SDL will pick this up and carry
on with the new default. This is different from our unplug detection for
specific devices, as in those cases we want to send the app a disconnect
notification, instead of migrating transparently as we now do for default
devices.
Note that this should also work for capture devices; if the device changes,
SDL will start recording from the new default.
Fixes Bugzilla #4851.
This avoids the need to malloc something extra, use a semaphore, etc, and
fixes Emscripten with pthreads support, which might not spin up a web worker
until after SDL_CreateThread returns and thus can't wait on a semaphore at
this point in any case.
Fixes Bugzilla #5064.
Build is broken without EGL since version 2.0.12 and
https://hg.libsdl.org/SDL/rev/72cc4740dec2:
/home/giuliobenetti/autobuild/run/instance-1/output-1/build/sdl2-2.0.12/src/video/kmsdrm/SDL_kmsdrmvideo.c: In function 'KMSDRM_CreateSurfaces':
/home/giuliobenetti/autobuild/run/instance-1/output-1/build/sdl2-2.0.12/src/video/kmsdrm/SDL_kmsdrmvideo.c:394:5: error: unknown type name 'EGLContext'
EGLContext egl_context;
^
Fixes:
- http://autobuild.buildroot.org/results/fafd20a01591032662f9ca025fcea3478239cf3c
Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Build with directfb is broken due to a spurious '}' and a missing 'E'
since version 2.0.12 and https://hg.libsdl.org/SDL/rev/4c2dcf490cba:
/home/buildroot/autobuild/run/instance-2/output-1/build/sdl2-2.0.12/src/video/directfb/SDL_DirectFB_render.c: In function 'SetBlendMode':
/home/buildroot/autobuild/run/instance-2/output-1/build/sdl2-2.0.12/src/video/directfb/SDL_DirectFB_render.c:202:9: error: case label not within a switch statement
202 | case SDL_BLENDMODE_MUL:
| ^~~~
/home/buildroot/autobuild/run/instance-2/output-1/build/sdl2-2.0.12/src/video/directfb/SDL_DirectFB_render.c:205:67: error: 'DSBF_DSTCOLOR' undeclared (first use in this function); did you mean 'DSBF_DESTCOLOR'?
205 | SDL_DFB_CHECK(destsurf->SetSrcBlendFunction(destsurf, DSBF_DSTCOLOR));
| ^~~~~~~~~~~~~
Fixes:
- http://autobuild.buildroot.org/results/83ccefee68c2800c0544e6f40fa8bc8ee6b67b77
Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Andrei Kortunov
Hello. I try to implement an application for Android, which uses a new sensors API from 2.0.9 to control a camera rotation via built-in gyroscope, using the code from the test/testsensor.c as an example.
Gyroscope input itself works well, but an interval between SDL_SENSORUPDATE events is about 200ms (the SENSOR_DELAY_NORMAL, I believe), when I need the interval about 20-40ms (the SENSOR_DELAY_GAME or SENSOR_DELAY_FASTEST).
Test apps in Xcode-iOS/Test/TestiPhoneOS.xcodeproj weren't launching
in the most-recent release of Xcode and the iOS Simulator (version 11.3.1).
This was caused by their shared Info.plist file not defining a
CFBundleShortVersionString (as reported by Xcode, when launching a test
app from within Xcode).
If a driver's implementation of CreateWindowFramebuffer sets the window
surface, use that rather than overwriting it. A driver may set the window
surface if data cannot be passed via the CreateWindowFramebuffer output
parameters (e.g. surface palette colors).
Otherwise our cached state goes out of sync when updating a texture. Since
these state changes aren't necessary, they were removed instead of updating
the cached state.
Fixes Bugzilla #4998.
bluenaxela+sdl
I've noticed that the Switch Pro Controller hidapi driver does not report battery levels when connected via Bluetooth, despite having code for setting joystick->epowerlevel.
This is caused by the driver always using k_eSwitchInputReportIDs_SimpleControllerState via Bluetooth. Using that mode means that the state reports you get back from the controller do not include battery state. Not using the full controller state over Bluetooth effectively makes this driver's support for setting joystick->epowerlevel entirely pointless, only ever reporting SDL_JOYSTICK_POWER_WIRED.
Is there a reason this was set to only use SimpleControllerState via Bluetooth?
I've attached a patch I'm using to allow getting battery level for the Switch Pro Controller.
A couple notes about this patch:
1) It changes LoadStickCalibration to accept the input_mode that is selected, because that's really what should determine what is used for stick extents, since stick extents differ between the modes.
2) In my patch I only use FullControllerState when the vid/pid matches the official Switch Pro Controller, as a cautionary measure in case some third-party controllers have problems with FullControllerState mode via Bluetooth (I noticed a HORI Wireless Switch Pad I had seemed to not read controller calibration correctly for stick extents. Maybe it's calibration data was uninitialized on account of having never been used with a Switch? I'm unsure, though if that guess is right maybe SDL2 should be detecting an uninitiated calibration state and using some sensible defaults)
There are a number of poorly behaved HID devices that time out on attempts to
read various strings. Rather than end up on an endless treadmill of blacklisting
broken devices, reduce our risk by only querying devices that are gamepads.
SDL_hidapijoystick.c already checks these same usages, so we shouldn't
exclude any working HID devices (caveat below).
This also makes HidP_GetPreparsedData() and HidP_GetCaps() failure skip
the device entirely, but that seems desired. If a device can't even return basic
top-level collection data properly, we want nothing to do with that broken device.
If we do find devices that work with HIDAPI joystick and fail these calls, we can
add an exception via VID+PID matching.
Sam Lantinga
Ryan C. Gordon
Michael Maltese
Paul Cercueil
Jay Petacat
Flamefire
David Ludwig
Fabrice Fontaine
Cameron Gutman