When Android presents an input event to an app, it wants the app to
return true or false depending on whether the app handled the event or
not. If the event wasn't handled by the app, it will be passed on to
the system, which may decide to take an action depending on what kind
of input event it is. For instance, if a B button press is passed on to
the system, it will be turned into a Back press. But if an R1 press is
passed on to the system, nothing in particular happens.
It's important that we get this return value right in Dolphin. For
instance, the user generally wouldn't want a B button press to open
the EmulationActivity menu, so B button presses usually shouldn't be
passed on to the system - but volume button presses usually should be
passed on to the system, since it would be hard to adjust the volume
otherwise. What ButtonManager did was to pass on input events that are
for a button which the user has not mapped, which I think makes sense.
But exactly how to implement that is more complicated in the new input
backend than in ButtonManager, because now we have a separation between
the input backend and the code that keeps track of the user's mappings.
What I'm going with in this commit is to treat an input as mapped if
it has been polled recently. In part I chose this because it seemed
like a simple way of implementing it that wouldn't cause too many
layering violations, but it also has two useful side effects:
1. If a controller is not being polled (e.g. GameCube controllers in
Wii games that don't use them), its mappings will not be considered.
2. Once sensor input is implemented in the Android input backend,
we will be able to use this "polled recently" tracking to power down
the sensors at times when the game is using a Wii Remote reporting
mode that doesn't include motion data. (Assuming that the sensor
inputs only are mapped to Wii Remote motion controls, that is.)
Android doesn't let us poll inputs whenever we want. Instead, we
listen to input events (activities will have to forward them to the
input backend), and store the received values in atomic variables
in the Input classes. This is similar in concept to how ButtonManager
worked, but without its homegrown second input mapping system.
ButtonManager is very different from how a normal input backend works,
and is making it hard for us to improve controller support on Android.
The following commits will add a new input backend in its place.
When that setting is enabled, m_xfb_entry is initially not present (during the phase where a shader compilation progress bar would be shown). The main path checks for m_xfb_entry, but the software renderer fallback path didn't.
Fixes another aspect of https://bugs.dolphin-emu.org/issues/13172.
Before, it used a fallback where it returned a default object, where the width and height were set to 0. Presenter::Initialize() used GetSurfaceInfo to set the backbuffer size, then used that size when initializing the on-screen UI (even for the software renderer, where the on-screen UI isn't currently present), which meant that ImGui got a window size of 0 and thus resulted in a failed assertion.
Although BindBackbuffer checks for size changes, it doesn't help because ImGui has already been initialized, and the size hasn't actually changed since initialization occured.
Fixes one aspect of https://bugs.dolphin-emu.org/issues/13172.
This second stack leads to JNI problems on Android, because ART fetches
the address and size of the original stack using pthread functions
(see GetThreadStack in art/runtime/thread.cc), and (presumably) treats
stack addresses outside of the original stack as invalid. (What I don't
understand is why some JNI operations on the CPU thread work fine
despite this but others don't.)
Instead of creating a second stack, let's borrow the approach ART uses:
Use pthread functions to find out the stack's address and size, then
install guard pages at an appropriate location. This lets us get rid
of a workaround we had in the MsgAlert function.
Because we're no longer choosing the stack size ourselves, I've made some
tweaks to where the put the guard pages. Previously we had a stack of
2 MiB and a safe zone of 512 KiB. We now accept stacks as small as 512 KiB
(used on macOS) and use a safe zone of 256 KiB. I feel like this should
be fine, but haven't done much testing beyond "it seems to work".
By the way, on Windows it was already the case that we didn't create
a second stack... But there was a bug in the implementation!
The code for protecting the stack has to run on the CPU thread, since
it's the CPU thread's stack we want to protect, but it was actually
running on EmuThread. This commit fixes that, since now this bug
matters on other operating systems too.
JosJuice
Minty-Meeo
MaiandGitHub
Pokechu22
iwubcode
Admiral H. Curtiss