Sylvain
If you play with the TouchScreen with +3 fingers randomly / pressing simultaneously all fingers.
You triggers FINGER DOWN events, but not always all the associated FINGER UP events.
So, after a while SDL_GetNumFingers() can report a wrong number of fingers pressed !
The explanation is hidden there : http://developer.android.com/reference/android/view/MotionEvent.html
Each pointer has a unique id that is assigned when it first goes down (indicated by ACTION_DOWN or ACTION_POINTER_DOWN).
A pointer id remains valid until the pointer eventually goes up (indicated by ACTION_UP or ACTION_POINTER_UP) or when the gesture is canceled (indicated by ACTION_CANCEL).
in ACTION_CANCEL :
The current gesture has been aborted. You will not receive any more points in it. You should treat this as an up event, but not perform any action that you normally would.
Constant Value: 3 (0x00000003)
Lets Android take care of which is the primary pointer (the one acting as the
mouse in SDL), reorganized the Java side code as well to make it easier to
understand.
Thanks to Denis Bernard!
Also, changed the Android manifest so the app doesn't quit with orientation
changes, and made testgles.c exit properly on Android.
This bumps the build SDK level to 12 (up from 10). Runtime requirements remain
the same (at API level < 12 joystick support is disabled).
Also enables building SDL for armv7 and x86.
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.
Denis Bernard
This patch to Android.mk adds support for static linking of libSDL for Android applications. A patched readme with static build instructions is also provided.
It does not break existing build environments setup according to the README-android.txt since the static library version will not be built in not required.
The static build uses the Android NDK module system (see docs/IMPORT-MODULE.html in the NDK folder and step 5 in the instructions below).
Instructions:
1. Copy the android-project directory wherever you want to keep your projects
and rename it to the name of your project.
2. Create a symlink to SDL/src/main/android/SDL_android_main.c as
<project>/jni/src/SDL_android_main.c
3. Rename <project>/jni/src/Android_static.mk to <project>/jni/src/Android.mk
(overwrite the existing one)
4. Edit <project>/jni/src/Android.mk to include your source files
5. create and export an environment variable named NDK_MODULE_PATH that points
to the parent directory of this SDL directory. e.g.:
export NDK_MODULE_PATH="$PWD"/..
6. Edit <project>/src/org/libsdl/app/SDLActivity.java and remove the call to
System.loadLibrary("SDL2") line 42.
7. Run 'ndk-build' (a script provided by the NDK). This compiles the C source
Although this requires an environment variable to be setup, it can be added once and for all to the main Android.mk of the project.
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.
C++ is a bit of a minefield on Android. Much functionality still doesn't work, and Android can't decide on which C++ standard library to use, so it provides 3 different ones, all of which are incompatible with each other. (It looks like clang is coming too which will add a new compiler and a 4th standard library.)
As middleware, SDL might be distributed as a binary and intermixed with other projects already using C++. If C++ is intermixed in a bad way, bad things will happen. Removing dependencies on C++ will avoid this problem and downstream users won't have to worry/care.
Philipp Wiesemann
SDL's Android project template has old default icons from Android while iOS project template has custom icons with SDL's logo.
There is a Wizard in the Android Developer Tools to create "Android Icon Sets". As an example I created icons from the iOS loading screen and attached them in a ZIP archive. They are named "ic_launcher.png" instead of "icon.png" because that is the new name used in Android projects. To use them the AndroidManifest.xml needs to be changed to have "@drawable/ic_launcher" instead of "@drawable/icon". I do not know why there was no icon created for ldpi. Maybe it is deprecated.
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.
Alexey Petruchik
Please remove local.properties from android-project folder and add it to hgignore
According to the local.properties:
# This file must *NOT* be checked in Version Control Systems,
ny00@outlook.com
Let me quote the following opening tag from
android-project/AndroidManifest.xml:
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
<!-- Replace org.libsdl.app with the identifier of your game, e.g.
com.gamemaker.game
-->
package="org.libsdl.app"
android:versionCode="1"
android:versionName="1.0"
android:installLocation="auto">
The comment (with the text "Replace org.libsdl.app with...") seems to be a
cause of troubles. Here are a few examples I've spotted:
1) While using nkd-build from android-ndk-r8d, I receive the following error:
Invalid attribute name: <!-- replace org.libsdl.app with the identifier of your
game, e.g.
com.gamemaker.game
--
/home/ny00123/util/android-ndk-r8d/build/gmsl/__gmsl:512: *** non-numeric
second argument to `wordlist' function: ''. Stop.
2) Repeating this but with android-ndk-r6b (an earlier revision), it reduces to
a warning and actual complication is not halted.
3) Following the instructions in README.android and using Eclipse (from a
recently downloaded ADT Bundle), I cannot seem to be able to create an Android
project from existing sources (one of the SDL test apps for now).
* On a side note, I can't find where I may choose the "Build Target" before
clicking "Finish", but it does not seem to be related to this bug report.
Anyway, following the choice of the project path and a click on "Finish",
nothing seems to occur.
If I rather do so after removing the above comment from AndroidManifest.xml,
though, the project appears on Eclipse as expected once I click on "Finish".
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.
morgan.devel@gmail.com 2012-01-13 00:32:23 PST
The android version of SDL_SYS_JoystickUpdate doesn't check if there is
actually new data and always generate the SDL_JOYAXISMOTION event.
Consequently, doing a while(SDL_PollEvent()) will result in an endless loop.
The attached patch fix this issue.
It also scale the incoming values properly in the Sint16 range. The scale from
[-gravity;+gravity] is done directly in the java part because one may want to
map the sensor values with a non-linear method for example.
Gabriel Jacobo 2011-12-23 12:55:11 PST
The attached files provide some improvement over the current handling of
pause/resume in Android.
- I disabled the exit(status) instruction in SDL_main as that makes the entire
app instead of the SDL thread exit (while not needed for pause/resume it is
needed for Live Wallpapers, an SDLActivity for which I'll upload in a separate
bug).
- Added nativePause and nativeResume which basically just mark the window as
visible/hidden, something that the end user needs to take into consideration
(ideally pausing the event loop).
Also, this arrangement creates a new GL context when needed, which at least in
my test system is every time you go away from the app and come back to it. So,
this means that the textures need to be generated again after resuming (a
problem the end user didn't have before because the app exited completely when
it should've been pausing). I'd like to know if there's a standard way of
letting the user know that the GL context has changed and that he needs to
refresh his textures, or if this is out of the scope of the library and each
user handles it in their own way (I don't know how/if this same thing is
handled in the iPhone backend, but it would be wise to try to imitate that).
Gabriel Jacobo 2011-12-23 12:57:10 PST
Also, in the SDLActivity the EGL handling code is moved up to the Activity from
the Surface code, as I think it is possible (in theory) that the surface is
destroyed temporarily while the context remains alive (though in practice in my
test system this is not the case)
* Formalized the interface with Java methods in SDL_android.h
* We don't need the feature system, at least right now
* Fixed waiting for the SDLMain thread
