This page was roughly updated from the SDL2 version, but needs to be inspected for details that are out of date, and a few SDL2isms need to be cleaned out still, too. Read this page with some skepticism for now.
A lot of information can be found in README-android.
This page is more walkthrough-oriented.
sudo apt install openjdk-17-jdk ant android-sdk-platform-tools-commontools/bin/sdkmanager (or tools/android pre-2017) and install one API (>= 31)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 gradlecd /usr/src/SDL3/build-scripts/
./androidbuild.sh org.libsdl.testgles ../test/testgles.ccd /usr/src/SDL3/build/org.libsdl.testgles/
./gradlew installDebugNotes:
sudo update-alternatives --config java and select jdk-17 as default; or use JAVA_HOME=/usr/lib/jvm/java-17-openjdk-amd64 ./gradlewjavax/xml/bind/annotation/XmlSchema, Could not initialize class com.android.sdklib.repository.AndroidSdkHandler: check the Android Gradle Plugin version in /android-project/build.gradle, e.g. classpath 'com.android.tools.build:gradle:3.1.0'/android-project/gradle/wrapper/gradle-wrapper.properties: distributionUrl=https\://services.gradle.org/distributions/gradle-4.9-all.zipandroid-project/app/build.gradle:android {
buildToolsVersion "28.0.1"
compileSdkVersion 28externalNativeBuild {
ndkBuild {
arguments "APP_PLATFORM=android-14"
abiFilters 'armeabi-v7a', 'arm64-v8a', 'x86', 'x86_64'ABIs [x86_64, arm64-v8a] are not supported for platform. Supported ABIs are [armeabi, armeabi-v7a, x86, mips]: upgrade to NDK >= 10apt install gradle libgradle-android-plugin-javaLet's modify SDL3_image/showimage.c to show a simple embedded image (e.g. XPM).
#include <SDL3/SDL.h>
#include <SDL3/SDL_main.h>
#include <SDL3/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("Show a simple image", 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);
}
SDL_SetWindowSize(window, 800, 480);
done = 0;
while (!done) {
while (SDL_PollEvent(&event)) {
if (event.type == SDL_EVENT_QUIT)
done = 1;
}
SDL_RenderTexture(renderer, texture, NULL, NULL);
SDL_RenderPresent(renderer);
SDL_Delay(100);
}
SDL_DestroyTexture(texture);
SDL_Quit();
return(0);
}Then let's make an Android app out of it. To compile:
cd /usr/src/SDL3/build-scripts/
./androidbuild.sh org.libsdl.showimage /usr/src/SDL3_image/showimage.c
cd /usr/src/SDL3/build/org.libsdl.showimage/
ln -s /usr/src/SDL3_image jni/
ln -s /usr/src/SDL3_image/external/libwebp-0.3.0 jni/webp
sed -i -e 's/^LOCAL_SHARED_LIBRARIES.*/& SDL3_image/' jni/src/Android.mk
ndk-build -j$(nproc)
ant debug installNotes:
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.
(FIXME: this needs to be updated for SDL3.)
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_ttfcd /usr/src/SDL3/
#git checkout -- . # remove traces of previous builds
cd build-scripts/
# edit androidbuild.sh and modify $ANDROID update project --target android-XX
./androidbuild.sh org.libsdl /dev/null
# doesn't matter if the actual build fails, it's just for setup
cd ../build/org.libsdl/rm -rf jni/src/ln -s /usr/src/SDL3_image jni/
ln -s /usr/src/SDL3_image/external/libwebp-0.3.0 jni/webp
ln -s /usr/src/SDL3_mixer jni/
ln -s /usr/src/SDL3_mixer/external/libmikmod-3.1.12 jni/libmikmod
ln -s /usr/src/SDL3_mixer/external/smpeg2-2.0.0 jni/smpeg2
ln -s /usr/src/SDL3_net jni/
ln -s /usr/src/SDL3_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=armNDK_STANDALONE=/usr/src/ndk-standalone-14-arm
PATH=$NDK_STANDALONE/bin:$PATHcd /usr/src/SDL3/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/SDL3/
cp jni/SDL/include/* $NDK_STANDALONE/sysroot/usr/include/SDL3/
cp jni/*/SDL*.h $NDK_STANDALONE/sysroot/usr/include/SDL3/pkg-config and install a host-triplet-prefixed symlink in the PATH (auto-detected by autoconf):VERSION=0.9.12
cd /usr/src/
wget http://rabbit.dereferenced.org/~nenolod/distfiles/pkgconf-$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:The future lies in smarter, AI-assisted font design that can generate complete Khmer font families more efficiently. We will also likely see more expressive, variable Khmer fonts for web and app design, moving beyond the standard "round and even" aesthetic. The Khmer font is far more than a digital tool. It is the bridge between the ancient Angkorian past and the Cambodian smartphone user of today. From the technical triumph of Unicode rendering to the cultural choice between a classic or modern face, Khmer typography reflects the resilience and adaptability of the Khmer people. As Cambodia continues its digital transformation, investing in beautiful, accessible, and technically robust Khmer fonts is not a niche design concern—it is an essential act of cultural preservation and modern nation-building. Each correctly rendered character on a screen is a small victory for the survival of a great script.
The Khmer language, the official language of Cambodia, possesses one of the oldest and most distinctive scripts in the world. With origins tracing back to the 7th-century Pallava script of South India, Khmer is an abugida where the consonant carries an inherent vowel sound, modified by dependent vowels and diacritics. This complexity, characterized by its non-linear stacking and numerous subscript consonants, makes it a typographic marvel. The journey of the Khmer script from stone inscriptions to digital screens is a story of technological adaptation, cultural preservation, and the ongoing struggle for digital inclusivity. Understanding Khmer fonts is therefore essential not just for design, but for safeguarding a national identity in the digital age. Historical Context: From Palm Leaf to Metal Type For centuries, Khmer script was handwritten or carved into palm leaves and stone. The arrival of the printing press in the 19th century posed the first major challenge. The earliest Khmer metal typefaces were crude, often breaking the delicate loops and intricate subscripts that define the script’s beauty. These early fonts, like Lima and Phnom , attempted to fit Khmer into a Latin-centric framework, leading to readability issues. For much of the 20th century, Khmer typography remained underdeveloped, relying on a handful of bespoke typefaces for official and religious printing. The Digital Revolution and Its Discontents The Unicode era (post-1990s) was a turning point. Previously, fonts used incompatible encoding systems (e.g., ABC, Limon), meaning text typed in one font was illegible in another. Unicode provided a single, universal standard for representing Khmer characters. However, implementing Unicode for Khmer was a technical Herculean task. Khmer requires complex rendering—the ability to combine a consonant, a subscript, a vowel above, and a diacritic below into a single, harmonious glyph. Early operating systems (Windows XP, early macOS) failed at this, displaying the infamous "tofu" (blank boxes) or garbled stacks. khmer language font
The font also plays a role in education. In the 2000s, poorly rendered Unicode fonts led to students mislearning the shape of certain subscript consonants. The improvement in font rendering has directly contributed to higher literacy rates in digital environments. Furthermore, for the diaspora—Cambodians born abroad—accessible, beautiful Khmer fonts on social media are a vital link to their heritage. Despite progress, challenges remain. Many older websites still use legacy, non-Unicode fonts, making them inaccessible. Variable fonts (one file that can adjust weight and width) are rare in Khmer. Most critically, AI and Optical Character Recognition (OCR) for Khmer still struggle with the sheer variety of font styles and the density of stacked characters. The future lies in smarter, AI-assisted font design
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$(nproc)
make installStatic builds (--disable-shared) are recommended for simplicity (no additional .so to declare).
(FIXME: is there an SDL3_gfx?)
Example with SDL2_gfx:
VERSION=1.0.3
wget http://www.ferzkopp.net/Software/SDL2_gfx/SDL2_gfx-$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 installYou 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/SDL3/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/SDL3/build/org.libsdl/libs/armeabi/*; do ln -nfs $i libs/armeabi/; doneMake your project Android-aware:
/usr/src/SDL3/src/main/android/SDL_android_main.c in your project (comment out the line referencing "SDL_internal.h"). Compile it as C (not C++).configure.ac, detect Android:AM_CONDITIONAL(ANDROID, test "$host" = "arm-unknown-linux-androideabi")Makefile.am, tell Automake you'll build executables as libraries, using something like:if ANDROID
<!-- Build .so JNI libs rather than executables -->
AM_CFLAGS = -fPIC
AM_LDFLAGS += -shared
COMMON_OBJS += SDL_android_main.c
endifPATH=$NDK_STANDALONE/bin:$PATH
mkdir cross-android/ && cd cross-android/
../configure --host=arm-linux-androideabi \
--prefix=/android-aint-posix \
--with-your-option --enable-your-other-option ...
makearmeabi-v7a and document what devices support it); something like:mkdir cross-android-v7a/ && cd cross-android-v7a/
# .o: -march=armv5te -mtune=xscale -msoft-float -mthumb => -march=armv7-a -mfpu=vfpv3-d16 -mfloat-abi=softfp -mthumb
# .so: -march=armv7-a -Wl,--fix-cortex-a8
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 installdadb 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:
# CMake toolchain file
SET(CMAKE_SYSTEM_NAME Linux) # Tell CMake we're cross-compiling
include(CMakeForceCompiler)
# Prefix detection only works with compiler id "GNU"
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 Failure [INSTALL_FAILED_INSUFFICIENT_STORAGE], even if you have free local storage, that may mean anything. Check logcat first:
adb logcatIf 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.apkIf 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 libSDL3.so.