This mixer type was added in
943b4c2036 because "anything which
produces sampled data with high latency (like the MT-32 emulator)
will sound terribly", but as far as I can see (or reproduce), this
mixer doesn't do anything that would solve that problem, except
that it effectively doubles the size of the audio buffer so there's
less chance of an underflow due to slower-than-realtime synthesis
by the softsynth. But you don't need the overhead of a separate
thread to do that, you just need to increase the buffer size.
If it turns out that everything that had previously been fixed by
this manager is broken by this change, everything that had been
fixed probably could have been fixed by just increasing the audio
buffer size in SdlMixerManager. :\
The previous default buffer size of 4096 samples for 44kHz mixer
would add up to 93ms of audio latency, which is fine for early
adventure games, but this is significantly more latency than is
acceptable for games with full motion video. For these games,
the latency needs to be kept within roughly +15ms and -45ms of
video frame presentation to avoid lip sync problems. With this
change, the default audio buffer size is calculated to be 1024
samples at 44kHz (which happens to match what DOSBox uses).
There is a possibility that the reduced latency may cause issues
that did not previously exist with things like the MT-32 emulator,
where a larger buffer size allowed for a larger window where
high-complexity synthesis that could not be generated in realtime
could be balanced out by low-complexity synthesis that could be
generated faster than realtime. In this case, rather than
increasing the system mixer buffer size again, please move the
MT-32 emulator into its own thread and give it its own larger ring
buffer into which it can generate more sample data in advance,
independently from the rest of the audio system.
For other systems where this buffer size reduction might cause a
problem with audio drop-outs, a new audio_buffer_size
configuration option has been added to allow users to tweak the
audio buffer size to match their machine's ability to generate
audio samples.
Fixes Trac#10033. Also improves playback of samples in SCI that
were programmed to restart across several consecutive frames,
relying on lower audio latency in the original engine for this to
not sound bad, like the hopping sound at the start of chapter 1
of KQ7, and the sound of turning on the power in the digger train
in the Lighthouse volcano.
Removing this GUI control was suggested as far back as 2011 at
<http://lists.scummvm.org/pipermail/scummvm-devel/2011-November/010416.html>.
There were no objections, but it was never removed. When working
on audio latency bugs, I independently rediscovered that the GUI
option was broken: the per-game options would *never* work, and the
option would not take effect until ScummVM was restarted because
there is no API for interacting with the backend audio mixer. So
now, it is finally gone.
Primarily for the sake of future troubleshooting, configurability
of the audio sample frequency within SdlMixerManager is maintained
for the moment, but now users will need to edit their ScummVM
configuration file manually to change it.
_hwscreen is always initialized to 16bpp so the supported 32bpp
pixel formats would never be put into the list of supported pixel
formats, making it useless for engines to query for usable 32bpp
pixel formats.
This patch changes things so that the native desktop pixel format
is at the top of the supported formats list, and all pixel formats
<= the default desktop pixel format will now show up in the list
of supported formats. ("Supported" is somewhat of a misnomer here
since there is no hardware querying beyond checking the default
desktop pixel format. SDL generally accepts a wide variety of pixel
formats and tries to convert them to whatever the hardware
supports.)
When -Wundeclared-selector is enabled (recommended by Apple), the
calls to the setBadgeLabel selector in MacOSXTaskbarManager are
warned on because NSDockTile declarations are not included because
they do not exist in macOS 10.4 and earlier. While I don't know
that we are even supporting such old macOS versions these days, it
is simple enough to fix this problem when compiling to modern
macOS versions by conditionally including the necessary header.
Previously we were clearing the whole backbuffer for 3 frames after a
window size change, and then only clearing the game area. This assumes
the OpenGL driver uses at most 3 render buffer and uses them in
sequential order. This does not seem to be the case on Linux when using
an Intel integrated GPU.
Instead we now clear the whole backbuffer on each frame to make sure
there are no leftovers remaining on the screen. All semi-recent GPUs
should have hardware clear anyway so this should not impact negatively
performance.
Possibly fixes#10025.
The thread locale concerns display options (e.g. date formatting) not
the display language. There are typically, but not necessarily the same,
as Windows allows them to be configured separately.
The call to SDL_SetWindowSize works around a macOS specific SDL2 bug.
Fixes the window not restoring to its previous position when exiting
fullscreen on Linux/X11.
When updating or recreating the window, if we changed the window
size at the same time we also toggle between OpenGL and non
OpenGL mode, or toggle fullscreen mode, we may have a pending
SDL resize event with the wrong size. So we need to make sure to
append another one with the correct size to end up with the correct
size. This fixes bug #9971.
This fixes tons of warnings with clang from a recent xcode version on
macOS (and possibly other systems) complaining that an instantiation
of _singleton is required but no definition is available.
Destroying and recreating the SDL window whenever the video mode
changes in SDL2 is not necessary and causes several problems:
1. In windowed mode, the game window shifts position;
2. In fullscreen mode in macOS, every time the window is
recreated, it causes the OS to play its switch-to-fullscreen
animation again and emit system alert noises;
3. The window content flickers; and
4. The engine loses events from the old destroyed window.
This patch changes the SDL backend code to avoid destroying and
recreating the SDL window when using SDL2, except when switching
OpenGL modes, since there is no way to change the OpenGL feature
of a window.
There are still some outstanding issues with OpenGL where window
size ends up getting reset even though the user has resized it;
this will probably need to be addressed at some point in another
patch.
Thanks to @bgK and @criezy for their feedback which made this
patch much better.
Co-Authored-By: Bastien Bouclet <bastien.bouclet@gmail.com>
Updating the cursor's texture is not necessary if it is not going to be drawn.
Fixes glDrawArrays sometimes failing due to using a framebuffer with an
incomplete color attachment. In SCI32 games, the framebuffer is incomplete
because the engine does not define pixel data for the cursor.
Thierry Crozat
Cameron Cawley
Vincent Bénony
Bastien Bouclet
Colin Snover
Eugene Sandulenko
Torbjörn Andersson
Frank Richter
Vincent Pelletier
Schrijvers Luc
lubomyr