Working for Android (on macOS)

Building raylib for Android on MAC OSX

It's helpful to know step by step what each part of the process is doing. For this, let's create a simple bash script, where each line can be run manually and the results can be seen. This should be useful for understanding the process on Linux as well.

This is simple as in we're just using shell commands, no cmake, no builders of any kind.

Initial folder setup

Note: project.c is copied from raylib/templates/simple_game/simple_game.c

/toolchain_arm_api28    put android_toolchain_arm_api28 here
/raylib                 put raylib here
/project1/lib
/project1/obj
/project1/src
/project1/dex
/project1/res/values/strings.xml
/project1/assets
/project1/project.c
/project1/AndroidManifest.xml

/res/values/strings.xml

Note: This is likely not necessary.

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="app_name">My App</string>
</resources>

/src/com/seth/project/NativeLoader.java

Note: My project is named "project" and the namespace is named "seth"

package com.seth.project; 
public class NativeLoader extends android.app.NativeActivity { 
    static {
        System.loadLibrary("project"); // must match name of shared library (in this case libproject.so) 
    } 
} 

AndroidManifest.xml

Note: "package" is the unique name of your project, this will overwrite apps with the same name

<?xml version='1.0' encoding="utf-8" ?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package='com.seth.project' android:versionCode='0'
    android:versionName='0' >
    <application>
        <activity android:name="com.seth.project.NativeLoader"
            android:theme="@android:style/Theme.NoTitleBar.Fullscreen"
            android:configChanges="orientation|keyboardHidden|screenSize"
            android:launchMode="singleTask"
            android:clearTaskOnLaunch="true">
        <meta-data android:name="android.app.lib_name" android:value="project"/>
            <intent-filter>
                <category android:name='android.intent.category.LAUNCHER'/>
                <action android:name='android.intent.action.MAIN'/>
            </intent-filter>
        </activity>
    </application>
</manifest>

Outline of the Process

cp              Copy libs from raylib to lib
gcc             Gen native_app_glue.o from raylib
ar rcs          Gen obj/libnative_app_glue.a from native_app_glue.o
gcc             Gen project.o from project.c
gcc             Gen lib/libproject.so from obj/project.o
aapt package    Gen R.java
javac           Gen classes from R.java and NativeLoader.java
dx              Gen classes.dex from objects
aapt package    Gen project.unsigned.apk
aapt add        Add shared library to project.unsigned.apk
keytool         Generate keystore
jarsigner       Gen project.signed.apk 
zipalign        Align project
adb install     Install project
adb logcat      view log

Install Standalone Toolchain

Install ndk-bundle using Android Studio. Install this in t

~/Library/Android/sdk/ndk-bundle/build/tools/make-standalone-toolchain.sh --arch=arm --platform=android-28 --install-dir=./toolchain_arm_api28

Install raylib

Compile raylib into ./raylib

~/.bash_profile

Add these files to path so you won't have a big headache later on

export ANDROID_SDK_ROOT="/Users/watchmyfeet/Library/Android/sdk"
export PATH="${ANDROID_SDK_ROOT}/build-tools/27.0.3/:$PATH"
export PATH="${ANDROID_SDK_ROOT}/tools:$PATH"
export PATH="${ANDROID_SDK_ROOT}/tools/bin:$PATH"
export PATH="${ANDROID_SDK_ROOT}/platform-tools:$PATH"

Initial Project Setup

Note: Keytool is in java folder on system

cd project1
mkdir lib/armeabi-v7a
cp ../raylib/src/libraylib.a lib/armeabi-v7a/libraylib.a
keytool -genkeypair -validity 1000 -dname "CN=seth,O=Android,C=ES" -keystore project.keystore -storepass 'mypass' -keypass 'mypass' -alias projectKey -keyalg RSA

Build Script

Note: Here's step by step commands which lead to the installation of your project!

../toolchain_arm_api28/bin/arm-linux-androideabi-gcc -c ../raylib/src/external/android/native_app_glue/android_native_app_glue.c -o obj/native_app_glue.o -std=c99 -march=armv7-a -mfloat-abi=softfp -mfpu=vfpv3-d16 -ffunction-sections -funwind-tables -fstack-protector-strong -fPIC -Wall -Wa,--noexecstack -Wformat -Werror=format-security -no-canonical-prefixes -DANDROID -DPLATFORM_ANDROID -D__ANDROID_API__=28

# Requires: folder setup
# Creates: obj/native_app_glue.o
# Note: This gcc uses other tools in the same toolchain folder structure, don't even thing about symlinking to it.

../toolchain_arm_api28/bin/arm-linux-androideabi-ar rcs obj/libnative_app_glue.a obj/native_app_glue.o

# Requires: obj/native_app_glue.o
# Creates: obj/libnative_app_glue.a

../toolchain_arm_api28/bin/arm-linux-androideabi-gcc -c project.c -o obj/project.o -I. -I../raylib/src -I../raylib/src/external/android/native_app_glue -std=c99 -march=armv7-a -mfloat-abi=softfp -mfpu=vfpv3-d16 -ffunction-sections -funwind-tables -fstack-protector-strong -fPIC -Wall -Wa,--noexecstack -Wformat -Werror=format-security -no-canonical-prefixes -DANDROID -DPLATFORM_ANDROID -D__ANDROID_API__=28 --sysroot=../toolchain_arm_api28/sysroot

# Requires: project.c
# Creates: obj/project.o

../toolchain_arm_api28/bin/arm-linux-androideabi-gcc -o lib/armeabi-v7a/libproject.so obj/project.o -shared -I. -I../raylib/src -I../raylib/src/external/android/native_app_glue -Wl,-soname,libproject.so -Wl,--exclude-libs,libatomic.a -Wl,--build-id -Wl,--no-undefined -Wl,-z,noexecstack -Wl,-z,relro -Wl,-z,now -Wl,--warn-shared-textrel -Wl,--fatal-warnings -u ANativeActivity_onCreate -L. -Lobj -Llib/armeabi-v7a -lraylib -lnative_app_glue -llog -landroid -lEGL -lGLESv2 -lOpenSLES -latomic -lc -lm -ldl

# Requires: obj/project.o
# Creates: lib/armeabi-v7a/libproject.so

aapt package -f -m -S res -J src -M AndroidManifest.xml -I ${ANDROID_SDK_ROOT}/platforms/android-28/android.jar

# Requires: AndroidManifest.xml, res/
# Creates: src/com/seth/project/R.java

javac -verbose -source 1.7 -target 1.7 -d obj -bootclasspath `/usr/libexec/java_home`/jre/lib/rt.jar -classpath ${ANDROID_SDK_ROOT}/platforms/android-28/android.jar:obj -sourcepath src src/com/seth/project/R.java src/com/seth/project/NativeLoader.java

# Requires: src/com/seth/project/R.java, src/com/seth/project/NativeLoader.java
# Creates: obj/com/seth/project/NativeLoader.class ... R&attr.class R$string.class R.class 

dx --verbose --dex --output=dex/classes.dex obj

# Requires: obj/com/seth/project/NativeLoader.class ... R&attr.class R$string.class R.class 
# Creates: dex/classes.dex

aapt package -f -M AndroidManifest.xml -S res -A assets -I ${ANDROID_SDK_ROOT}/platforms/android-28/android.jar -F project.unsigned.apk dex

# Creates: project.unsigned.apk
# Note: The "dex" at the end is the directory the classes.dex file is in! This folder can not contain the manifest file for whatever reason.

aapt add project.unsigned.apk lib/armeabi-v7a/libproject.so

# Does: Adds shared library to apk

jarsigner -keystore project.keystore -storepass mypass -keypass mypass -signedjar project.signed.apk project.unsigned.apk projectKey

# Does: Signs

zipalign -f 4 project.signed.apk project.apk

# Does: Aligns

adb install -r project.apk

# Does: install

Error: couldn't find libprojectlibrary.so

You'll get this if your shared library's name does not match across the build. In my case, I was referencing projectlibrary in the java file where it should have just been "project"

Error: INSTALL_FAILED_NO_MATCHING_ABIS

This one was tricky! Make sure the platform of the standalone toolchain you build matches the platform you are using on your system.

make-standalone-toolchain.sh --arch=arm --platform=android-28 --install-dir=./toolchain_arm_api28
${ANDROID_SDK_ROOT}/platforms/android-28

This command may also help.

adb shell getprop ro.product.cpu.abi

Error: INSTALL_FAILED_DEXOPT

This one was easier. The Apk generated must contain classes/classes.dex. If it doesn't, check aapt package -f -M to make sure you are including the folder dex is in at the end of it.

Dealing with Segmentation Faults - Using adb logcat

In the event of a segfault, don't despair! You can get the entire backtrace using adb logcat.

adb logcat "libc:*" "DEBUG:*" "*:S"

This gives you everything tagged with libc or DEBUG. "*:S" is there to Silence all other stuff.

Now, you may see a message that says "Suppressing debuggerd output because prctl(PR_GET_DUMPABLE)==0"

In that case you have to set this to 1.

In your c code, dd this include statement, and the prctl command somewhere early on in your main():

#include <sys/prctl.h>
...
prctl(PR_SET_DUMPABLE, 1, 0, 0, 0);

Here's a more robust logcat command:

adb logcat "threaded_app:*" "raylib:*" "libc:*" "DEBUG:*" "InputDispatcher:*" "JavaBinder:*" "WindowState:*" "Eve:*" "ViewRootImpl:*" "*:S"

Or be brave and try to find the important tags yourself:

adb logcat "*:*"