Denis Bernard
Background information: http://developer.android.com/reference/android/hardware/SensorEvent.html#values
Steps to reproduce: compile testjoystick.c as an android app (change screen size according to your device). While running the app, also run:
adb logcat -c; adb logcat -s 'SDL:*' 'SDL/APP:*'
When tilting the device left/right, the joystick moves in the opposite direction of what one would expect. Or at least, the behaviour is not consistent with the Y axis.
Also when the device sits on a table (obviously not moving), the Z axis value oscillates between -32000 and +32000 (by overflow):
I/SDL/APP ( 1994): Joystick 0 axis 2 value: 32511
I/SDL/APP ( 1994): Joystick 0 axis 2 value: 32575
I/SDL/APP ( 1994): Joystick 0 axis 2 value: 32383
I/SDL/APP ( 1994): Joystick 0 axis 2 value: -32386
I/SDL/APP ( 1994): Joystick 0 axis 2 value: -32450
I/SDL/APP ( 1994): Joystick 0 axis 2 value: -32578
This is caused by the accelerometer yielding a constant value around 9.81 for Z and feeding something like 0.9 to 1.1 to the joystick driver, resulting in the overflow.
Proposed fix in SDLActivity.java (swap X and subtract G from Z reading)
Denis Bernard
Background information: http://android-developers.blogspot.fr/2010/09/one-screen-turn-deserves-another.html and http://developer.android.com/reference/android/hardware/SensorEvent.html
Right now, the Android accelerometer event handler feeds raw accelerometer data to the SDL Joystick driver. The result is that for landscape-only applications, the axis need to be swapped if running on a portrait device (like a phone), and vice-versa: running a portrait only app on a landscape device like a tablet.
The purpose of this patch is to perform coordinate remapping of the accelerometer data before feeding it to the SDL joystick driver so that the X axis of the joystick is always aligned with the X axis of the display, same for the Y axis.
This has been tested on applications that support screen orientation changes as well as applications with fixed screen orientations, both on phones and tablets.
On Android available touch devices are now added with video initialization (like
the keyboard). This fixes SDL_GetNumTouchDevices() returning 0 before any touch
events happened although there is a touch screen available. The adding of touch
devices after a touch event was received is still active to allow connecting
devices later (if this is possible) and to provide a fallback if the new init
did not work somehow. For the implementation JNI was used and API level 9 is
required. There seems to be nothing in the Android NDK's input header (input.h)
to implement everything on C side without communication with Java side.
If the app is in landscape mode and the user presses the power button, a pause
is followed immediately by a surfaceChanged event because the lock screen
is shown in portrait mode. This triggers a "false" resume.
So, we just pause and resume following the onWindowFocusChanged events.
Also, wait for SDL_APP_WILLENTERBACKGROUND and SDL_APP_DIDENTERBACKGROUND before
blocking the event pump.
Joseba García Echebarria
The current version of SDL HG in Android doesn't do anything when volume keys are pressed.
The change makes SDL ignore volume keys so that they're handled by the OS and the sound volume can be changed within an app.
wjp
In SDL HG (2.0) the pixel format constants in
android-project/src/org/libsdl/app/SDLActivity.java seem to have gone out of
sync with include/SDL_pixels.h in HG rev b1124b32b07d.
E.g., at a glance it seems like 0x85151002 should have become 0x15151002.
Philipp Wiesemann 2012-10-06 07:19:57 PDT
SDL does not use values set with SDL_GL_SetAttribute on Android.
I attached a patch which adds this functionality and makes it possible to set
(for example) depth buffer size or anti-aliasing in the actual application
instead of modifying the Java source (which seems currently the only way).
The functions to show/hide/toggle the on-screen keyboard have been folded into the text input state.
Calling SDL_StartTextInput() will automatically show the on-screen keyboard if it's available.
Calling SDL_StopTextInput() will automatically hide the on-screen keyboard if it's available.
There is a new API function SDL_IsTextInputActive() which will return whether text input is currently active.
Text input is disabled by default, you must call SDL_StartTextInput() when you are ready to accept text input.
SDL_HasScreenKeyboardSupport() no longer needs to be passed a window.
The iPhone-specific on-screen keyboard functions have been removed.
Added information on how to customize your application name and icon.
Added information on using STL with an Android application
Increased the minimum API level to 10, because that's the lowest API
that currently has an emulator image for testing.
Andrey Isakov 2012-10-03 08:30:25 PDT
I've found out in the process of porting one OS project to Android/SDL2 that
there is no support for TextInput events/APIs on Android.
So I implemented some kind of initial support of that feature, and at the very
least it seems to work fine with latin chars input with soft and hardware
keyboards on my Moto Milestone2. I've also tried playing around with more
complex IMEs, like japanese, logging the process and it seemed to work too. I'm
not sure since the app itself I am working on does not have support for
non-latin input.
The main point of the patch is to place a fake input view in the region
specified by SDL_SetTextInputRect and create a custom InputConnection for it.
The reason to make it a separate view is to support Android's pan&scan on input
feature properly. For details please refer to
http://android-developers.blogspot.com/2009/04/updating-applications-for-on-screen.html
Even though the manual states that SetTextInputRect is used to determine the
IME variants position, I thought this would be a proper use for this too.
