A lot of information can be found in SDL/docs/README-android.md.
This page is more walkthrough-oriented.
* Install minimal Java environment. For instance, in Debian/Ubuntu:
sudo apt install openjdk-8-jdk ant android-sdk-platform-tools-common
tools/bin/sdkmanager
(or tools/android
pre-2017) and install one API (>=12; >= 19 for SDL >= 2.0.8; >=26 if for SDL >= 2.0.9)* Configure your environment variables, e.g.:
PATH="/usr/src/android-ndk-rXXx:$PATH" # for 'ndk-build'
PATH="/usr/src/android-sdk-linux/tools:$PATH" # for 'android'
PATH="/usr/src/android-sdk-linux/platform-tools:$PATH" # for 'adb'
export ANDROID_HOME="/usr/src/android-sdk-linux" # for gradle
export ANDROID_NDK_HOME="/usr/src/android-ndk-rXXx" # for gradle
cd /usr/src/SDL2/build-scripts/ ./androidbuild.sh org.libsdl.testgles ../test/testgles.c ```
cd /usr/src/SDL2/build/org.libsdl.testgles/ ant debug install # SDL <= 2.0.7 ./gradlew installDebug # SDL >= 2.0.8 ```
Notes:
```
repositories {
jcenter()
}
``` to ```
repositories {
jcenter()
google()
}
```
``` classpath 'com.android.tools.build:gradle:3.1.0' ```
``` distributionUrl=https\://services.gradle.org/distributions/gradle-4.9-all.zip ```
android {
buildToolsVersion "28.0.1"
compileSdkVersion 28
}}}
externalNativeBuild {
ndkBuild {
arguments "APP_PLATFORM=android-14"
abiFilters 'armeabi-v7a', 'arm64-v8a', 'x86', 'x86_64'
```
Let's modify SDL2_image/showimage.c
to show a simple embedded image (e.g. XPM).
#include "SDL.h"
#include "SDL_image.h"
/* XPM */
static char * icon_xpm[] = {
"32 23 3 1",
" c #FFFFFF",
". c #000000",
"+ c #FFFF00",
" ",
" ........ ",
" ..++++++++.. ",
" .++++++++++++. ",
" .++++++++++++++. ",
" .++++++++++++++++. ",
" .++++++++++++++++++. ",
" .+++....++++....+++. ",
" .++++.. .++++.. .++++. ",
" .++++....++++....++++. ",
" .++++++++++++++++++++. ",
" .++++++++++++++++++++. ",
" .+++++++++..+++++++++. ",
" .+++++++++..+++++++++. ",
" .++++++++++++++++++++. ",
" .++++++++++++++++++. ",
" .++...++++++++...++. ",
" .++............++. ",
" .++..........++. ",
" .+++......+++. ",
" ..++++++++.. ",
" ........ ",
" "};
int main(int argc, char *argv[])
{
SDL_Window *window;
SDL_Renderer *renderer;
SDL_Surface *surface;
SDL_Texture *texture;int done;
SDL_Event event;
if (SDL_CreateWindowAndRenderer(0, 0, 0, &window, &renderer) < 0) {
SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,"SDL_CreateWindowAndRenderer() failed: %s", SDL_GetError());
return(2);
}
surface = IMG_ReadXPMFromArray(icon_xpm);
texture = SDL_CreateTextureFromSurface(renderer, surface);if (!texture) {
SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,"Couldn't load texture: %s", SDL_GetError());
return(2);
}800, 480);
SDL_SetWindowSize(window,
0;
done = while (!done) {
while (SDL_PollEvent(&event)) {
if (event.type == SDL_QUIT)
1;
done =
}
SDL_RenderCopy(renderer, texture, NULL, NULL);
SDL_RenderPresent(renderer);100);
SDL_Delay(
}
SDL_DestroyTexture(texture);
SDL_Quit();return(0);
}
Then let's make an Android app out of it. To compile: ``` cd /usr/src/SDL2/build-scripts/ ./androidbuild.sh org.libsdl.showimage /usr/src/SDL2_image/showimage.c cd /usr/src/SDL2/build/org.libsdl.showimage/ ln -s /usr/src/SDL2_image jni/ ln -s /usr/src/SDL2_image/external/libwebp-0.3.0 jni/webp sed -i -e 's/^LOCAL_SHARED_LIBRARIES.*/& SDL2_image/' jni/src/Android.mk ndk-build -j$(nproc) ant debug install ```
Notes:
You use autotools in your project and can't be bothering understanding ndk-build's cryptic errors? This guide is for you!
Note: this environment can be used for CMake too.
cd /usr/src/ wget https://libsdl.org/release/SDL2-2.0.5.tar.gz wget https://www.libsdl.org/projects/SDL_image/release/SDL2_image-2.0.1.tar.gz wget https://www.libsdl.org/projects/SDL_mixer/release/SDL2_mixer-2.0.1.tar.gz wget https://www.libsdl.org/projects/SDL_net/release/SDL2_net-2.0.1.tar.gz wget https://www.libsdl.org/projects/SDL_ttf/release/SDL2_ttf-2.0.14.tar.gz
tar xf SDL2-2.0.5.tar.gz tar xf SDL2_image-2.0.1.tar.gz tar xf SDL2_mixer-2.0.1.tar.gz tar xf SDL2_net-2.0.1.tar.gz tar xf SDL2_ttf-2.0.14.tar.gz
ln -s SDL2-2.0.5 SDL2 ln -s SDL2_image-2.0.1 SDL2_image ln -s SDL2_mixer-2.0.1 SDL2_mixer ln -s SDL2_net-2.0.1 SDL2_net ln -s SDL2_ttf-2.0.14 SDL2_ttf ```
cd /usr/src/SDL2/ cd build-scripts/
./androidbuild.sh org.libsdl /dev/null
cd ../build/org.libsdl/ ```
rm -rf jni/src/ ```
ln -s /usr/src/SDL2_image jni/ ln -s /usr/src/SDL2_image/external/libwebp-0.3.0 jni/webp ln -s /usr/src/SDL2_mixer jni/ ln -s /usr/src/SDL2_mixer/external/libmikmod-3.1.12 jni/libmikmod ln -s /usr/src/SDL2_mixer/external/smpeg2-2.0.0 jni/smpeg2 ln -s /usr/src/SDL2_net jni/ ln -s /usr/src/SDL2_ttf jni/ ```
jni/Android.mk
to disable some formats, e.g.: ```SUPPORT_MP3_SMPEG := false include $(call all-subdir-makefiles) ```
ndk-build -j$(nproc) ```
Note: no need to add System.loadLibrary
calls in SDLActivity.java
, your application will be linked to them and Android's ld-linux loads them automatically.
Now:
/usr/src/android-ndk-r8c/build/tools/make-standalone-toolchain.sh \
--platform=android-14 --install-dir=/usr/src/ndk-standalone-14-arm --arch=arm
```
NDK_STANDALONE=/usr/src/ndk-standalone-14-arm PATH=$NDK_STANDALONE/bin:$PATH ```
cd /usr/src/SDL2/build/org.libsdl/ for i in libs/armeabi/*; do ln -nfs $(pwd)/$i $NDK_STANDALONE/sysroot/usr/lib/; done mkdir $NDK_STANDALONE/sysroot/usr/include/SDL2/ \cp jni/SDL/include/* $NDK_STANDALONE/sysroot/usr/include/SDL2/ \cp jni/*/SDL*.h $NDK_STANDALONE/sysroot/usr/include/SDL2/ ```
pkg-config
and install a host-triplet-prefixed symlink in the PATH (auto-detected by autoconf): ```VERSION=0.9.12 cd /usr/src/ wget http://rabbit.dereferenced.org/~nenolod/distfiles/pkgconf-$VERSION.tar.gz tar xf pkgconf-$VERSION.tar.gz cd pkgconf-$VERSION/ mkdir native-android/ && cd native-android/ ../configure --prefix=$NDK_STANDALONE/sysroot/usr make -j$(nproc) make install ln -s ../sysroot/usr/bin/pkgconf $NDK_STANDALONE/bin/arm-linux-androideabi-pkg-config mkdir $NDK_STANDALONE/sysroot/usr/lib/pkgconfig/ ```
.pc
files for SDL: ```cat <<'EOF' > $NDK_STANDALONE/sysroot/usr/lib/pkgconfig/sdl2.pc prefix=/usr/src/ndk-standalone-14-arm/sysroot/usr exec_prefix=${prefix} libdir=${exec_prefix}/lib includedir=${prefix}/include Name: sdl2 Description: Simple DirectMedia Layer is a cross-platform multimedia library designed to provide low level access to audio, keyboard, mouse, joystick, 3D hardware via OpenGL, and 2D video framebuffer. Version: 2.0.5 Requires: Conflicts: Libs: -lSDL2 Cflags: -I${includedir}/SDL2 -D_REENTRANT EOF
cat <<'EOF' > $NDK_STANDALONE/sysroot/usr/lib/pkgconfig/SDL2_image.pc prefix=/usr/src/ndk-standalone-14-arm/sysroot/usr exec_prefix=${prefix} libdir=${exec_prefix}/lib includedir=${prefix}/include Name: SDL2_image Description: image loading library for Simple DirectMedia Layer Version: 2.0.1 Requires: sdl2 >= 2.0.0 Libs: -L${libdir} -lSDL2_image Cflags: -I${includedir}/SDL2 EOF
cat <<'EOF' > $NDK_STANDALONE/sysroot/usr/lib/pkgconfig/SDL2_mixer.pc prefix=/usr/src/ndk-standalone-14-arm/sysroot/usr exec_prefix=${prefix} libdir=${exec_prefix}/lib includedir=${prefix}/include Name: SDL2_mixer Description: mixer library for Simple DirectMedia Layer Version: 2.0.1 Requires: sdl2 >= 2.0.0 Libs: -L${libdir} -lSDL2_mixer Cflags: -I${includedir}/SDL2 EOF
cat <<'EOF' > $NDK_STANDALONE/sysroot/usr/lib/pkgconfig/SDL2_net.pc prefix=/usr/src/ndk-standalone-14-arm/sysroot/usr exec_prefix=${prefix} libdir=${exec_prefix}/lib includedir=${prefix}/include Name: SDL2_net Description: net library for Simple DirectMedia Layer Version: 2.0.1 Requires: sdl2 >= 2.0.0 Libs: -L${libdir} -lSDL2_net Cflags: -I${includedir}/SDL2 EOF
cat <<'EOF' > $NDK_STANDALONE/sysroot/usr/lib/pkgconfig/SDL2_ttf.pc prefix=/usr/src/ndk-standalone-14-arm/sysroot/usr exec_prefix=${prefix} libdir=${exec_prefix}/lib includedir=${prefix}/include Name: SDL2_ttf Description: ttf library for Simple DirectMedia Layer with FreeType 2 support Version: 2.0.14 Requires: sdl2 >= 2.0.0 Libs: -L${libdir} -lSDL2_ttf Cflags: -I${includedir}/SDL2 EOF ```
You can add any other libraries (e.g.: SDL2_gfx, freetype, gettext, gmp...) using commands like: ``` mkdir cross-android/ && cd cross-android/ ../configure --host=arm-linux-androideabi --prefix=$NDK_STANDALONE/sysroot/usr \
--with-some-option --enable-another-option \
--disable-shared
make -j$(nproc) make install ```
Static builds (--disable-shared
) are recommended for simplicity (no additional .so
to declare).
Example with SDL2_gfx: ``` VERSION=1.0.3 wget http://www.ferzkopp.net/Software/SDL2_gfx/SDL2_gfx-$VERSION.tar.gz tar xf SDL2_gfx-$VERSION.tar.gz mv SDL2_gfx-$VERSION/ SDL2_gfx/ cd SDL2_gfx/ mkdir cross-android/ && cd cross-android/ ../configure --host=arm-linux-androideabi --prefix=$NDK_STANDALONE/sysroot/usr \
--disable-shared --disable-mmx
make -j$(nproc) make install ```
You can compile YOUR application using this technique, with some more steps to tell Android how to run it using JNI.
First, prepare an Android project:
/usr/src/SDL2/android-project
skeleton as explained in README-android.md
. You can leave it as-is in a first step.mkdir -p libs/armeabi/ for i in /usr/src/SDL2/build/org.libsdl/libs/armeabi/*; do ln -nfs $i libs/armeabi/; done ```
Make your project Android-aware:
/usr/src/SDL2/src/main/android/SDL_android_main.c
in your project (comment out the line referencing "SDL_internal.h"). Compile it as C (not C++).AM_CONDITIONAL(ANDROID, test "$host" = "arm-unknown-linux-androideabi") }}}
if ANDROID
AM_CFLAGS = -fPIC
AM_LDFLAGS += -shared
COMMON_OBJS += SDL_android_main.c
endif }}}
PATH=$NDK_STANDALONE/bin:$PATH mkdir cross-android/ && cd cross-android/ ../configure --host=arm-linux-androideabi \
--prefix=/android-aint-posix \
--with-your-option --enable-your-other-option ...
make ```
armeabi-v7a
and document what devices support it); something like: ```mkdir cross-android-v7a/ && cd cross-android-v7a/
CFLAGS="-g -O2 -march=armv7-a -mfpu=vfpv3-d16 -mfloat-abi=softfp -mthumb" LFDLAGS="-march=armv7-a -Wl,--fix-cortex-a8" \
../configure --host=arm-linux-androideabi \
...
```
Now you can install your pre-built binaries and build the Android project:
android-project/libs/armeabi/libmain.so
..apk
: ```android update project --name your_app --path . --target android-XX ant debug ant installd ```
adb shell am start -a android.intenon.MAIN -n org.libsdl.app/org.libsdl.app.SDLActivity # replace with your app package ```
(Work In Progress)
You can use our Android GCC toolchain using a simple toolchain file: ```
SET(CMAKE_SYSTEM_NAME Linux) # Tell CMake we're cross-compiling include(CMakeForceCompiler)
CMAKE_FORCE_C_COMPILER(arm-linux-androideabi-gcc GNU) SET(ANDROID TRUE) ```
You then call CMake like this: ``` PATH=$NDK_STANDALONE/bin:$PATH cmake \
-D CMAKE_TOOLCHAIN_FILE=../android_toolchain.cmake \
...
```
If ```ant installd``` categorically refuses to install with , even if you have free local storage, that may mean anything. Check logcat first: If the error logs are not helpful (likely ;')) try locating all past traces of the application: ``` find / -name "org...." ``` and remove them all.
If the problem persists, you may try installing on the SD card: ``` adb install -s bin/app-debug.apk ```
If you get in your logcat: ``` SDL: Couldn't locate Java callbacks, check that they're named and typed correctly ``` this probably means your ```SDLActivity.java``` is out-of-sync with your libSDL2.so.