This is the updated tutorial to set up and build an app with SDL2.0.10 in Android Studio 3.4.2 in Windows 10
This time I checked to make sure that the text formatting was correct efter I formattesd the quoted text. In the previous tutorial there were some missing characters. If you find some errors please point it out to make it easier for others. 
For this instructions we wish to create a app named DemolitionCrew. Change accordingly to your situation.
Since all the examples is from a real game I have just released on iOS, Android and Switch I will use its name.
We need to utilize not only the SDL2 main lib but also SDL2_Image, SDL2_net etc
I will compile and run this on a Samsung Galaxy S8+
1. Create this folder structure
Folder Structure
d:\Development\android
d:\Development\android\SDL2
d:\Development\android\SDL2_image
d:\Development\android\SDL2_mixer
d:\Development\android\SDL2_net
d:\Development\android\SDL2_ttf
2. Download these zip archives with source:
https://www.libsdl.org/download-2.0.php
https://www.libsdl.org/projects/SDL_image/
https://www.libsdl.org/projects/SDL_mixer/
https://www.libsdl.org/projects/SDL_net/
https://www.libsdl.org/projects/SDL_ttf
3. unpack every zip to individual folders
4. Copy the content to correct folders
From the SDL2.0.10 folder you copy the folder “android-project” to “d:\Development\android”
From the SDL2.0.10 folder you copy “include”,“src” and “Android.mk” to d:\Development\android\SDL2
From the “SDL2_image-2.0.5” folder you copy all files ending with .c and .h and the folder “external” and the file Android.mk to d:\Development\android\SDL2_image
From the “SDL2_ttf-2.0.15” folder you copy all files ending with .c and .h and the folder “external” and the file Android.mk to d:\Development\android\SDL2_ttf
From the “SDL2_net-2.0.1” folder you copy all files ending with .c and .h and the file Android.mk to d:\Development\android\SDL2_net
From the “SDL2_mixer-2.0.4” folder you copy all files ending with .c and .h and the folders “external”,“native_midi”,“timidity” and the file Androis.mk to d:\Development\android\SDL2_mixer
5a. Disable WebP in SDL_image
If you doesn’t have to have support for WebP you can edit the “Android.mk” file
so that line 16 says “SUPPORT_WEBP ?= false”
This time I just left it to true. It worked fine.
5b. Disable mp3 in SDL_Mixer
If you doesn’t have to support mp3 and can stick to OGG instead do disable this.
I tried around a bit until I got tired of the mpg123 issue. So this was my solution. (Brutal)
I guess this can all be solved by finding a correct library, but since I don’t use mp3 I just removed itsall together.
remove these lines in d:\Development\android\SDL2_mixer\Android.mk
SUPPORT_MP3_MPG123 ?= true
MPG123_LIBRARY_PATH := external/mpg123-1.25.6
and further down in the same file:
ifeq ($(SUPPORT_MP3_MPG123),true)
LOCAL_C_INCLUDES += $(LOCAL_PATH)/$(MPG123_LIBRARY_PATH)
LOCAL_CFLAGS += -DMUSIC_MP3_MPG123
LOCAL_SHARED_LIBRARIES += mpg123
endif
In the SDL_Mixer folder i removed these files:
d:\Development\android\SDL2_mixer\music_mpg123.h
d:\Development\android\SDL2_mixer\music_mpg123.c
The entire folder d:\Development\android\SDL2_mixer\external\mpg123-1.25.6
In the file d:\Development\android\SDL2_mixer\music.c I commented out line 40
//#include “music_mpg123.h”
If you discover this later on, a rebuild might not do it. In that case you just have to
remove the “debug” and “release” folder in
D:\Development\android\DemolitionCrew\app.externalNativeBuild\ndkBuild
This could ofcourse be handled better but I didn’t have time for it.
6. Create the Project.
In the folder “d:\Development\android”
Rename the folder “android-project” to what you want your project to be called.
In this case we name it “DemolitionCrew”
7. Start the command promt (WINKEY+R, Write “cmd” Enter)
Create these links so they will appear as linked folders in the project. It is important that
you have named your project folder in beforehand. Otherwise they diappear.
mklink /J d:\Development\android\DemolitionCrew\app\jni\SDL d:\Development\android\SDL2
mklink /J d:\Development\android\DemolitionCrew\app\jni\SDL_image d:\Development\android\SDL2_image
mklink /J d:\Development\android\DemolitionCrew\app\jni\SDL_mixer d:\Development\android\SDL2_mixer
mklink /J d:\Development\android\DemolitionCrew\app\jni\SDL_net d:\Development\android\SDL2_net
mklink /J d:\Development\android\DemolitionCrew\app\jni\SDL_ttf d:\Development\android\SDL2_ttf
8. Download and start Start Android Studio 3.4.2
I choosed to install it in “d:\Android Studio”
Start Android Studio
“Do not import settings” (I choosed this becuase I have a new installation)
“Android Studio Setup Wizard” will start
Choose “Standard”
Choose your prefered theme and then finish.
Android Studio will now download all the components.
Click on “Open an existing Android Studio Project”
Navigate to “d:\Development\android” and select your project. In this case “DemolitionCrew”.
Click “Open”
If this is the first time you run Android Studio it will need you to accept the Licence agreement.
In the right bottom window you will find a link that says “Install missing SDK packages”
Clicking on that will bring up a window where you can accept the licens agreement.
Click “agree” and the next.
Android studio will install all the components.
After that is done click “Finish”.
In the bottom right window it might say “Error: NDK not configured” Click on the link “Install NDK”
When done it will try to compile and fail.
9. Change view
In the almost top left corner you can alter the view between “Android” and “Project”
Change to “Project” if it is not already choosen.
Expand the tree view DemolitionCrew->app->src->main
Double Click on AndroidManifest.xml
Change the package=“org.libsdl.app” on line 6 to "package=“com.xirbx.games” (Or what your company and app name is)
The android:versionCode=“1” Not sure if this needs to be increased for each release on the google play store, but increase it anyways.
Change this to required true if you want touch screen to work on all smart phones.
<uses-feature
android:name="android.hardware.touchscreen"
android:required="true" />
Add these lines under the other permission lines if you wish SDL_net to access your local net and the internet
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
Save the file (CTRL+S)
10. Expand the tre view to this:
DemolitionCrew->app->jni
Double click on “Application.mk”
Uncomment line 5 so that it says “APP_STL := c++_shared”
Make sure line 10 says: “APP_PLATFORM=android-16”
Add a line underneath that says “APP_CPPFLAGS += -fexceptions”
Expand the tree to DemolitionCrew->app
Double click on build.gradle
Make sure line 16 says :
minSdkVersion 16
Make sure line 22 says:
arguments “APP_PLATFORM=android-16”
Change the ApplicationId on line 14 to this:
applicationId “com.xirbx.games.demolitioncrew”
NOTE! On line 18 you need to increase the versionCode for each build you
upload to Google Play
11. Expand the tre view to this:
DemolitionCrew->app->jni->src
Double click on “Android.mk”
Change line 14 from
LOCAL_SHARED_LIBRARIES := SDL2
to:
LOCAL_SHARED_LIBRARIES := SDL2 \ SDL2_image \ SDL2_mixer \ SDL2_ttf \ SDL2_net
Change line 12 from:
LOCAL_SRC_FILES := YourSourceHere.c
to
LOCAL_SRC_FILES := \ AssetManager.cpp \ Components.cpp \ ECS.cpp \ Game.cpp \ GameClient.cpp \ GameMap.cpp \ main.cpp \ TextureManager.cpp \ tinyxml2.cpp \ UrlReader.cpp \ Vector2D.cpp \ xmltest.cpp \ ResourcePath.cpp \ tmxparser/base64/base64.cpp \ tmxparser/miniz.c \ tmxparser/TmxColor.cpp \ tmxparser/TmxEllipse.cpp \ tmxparser/TmxGroupLayer.cpp \ tmxparser/TmxImage.cpp \ tmxparser/TmxImageLayer.cpp \ tmxparser/TmxLayer.cpp \ tmxparser/TmxMap.cpp \ tmxparser/TmxObject.cpp \ tmxparser/TmxObjectGroup.cpp \ tmxparser/TmxPolygon.cpp \ tmxparser/TmxPolyline.cpp \ tmxparser/TmxProperty.cpp \ tmxparser/TmxPropertySet.cpp \ tmxparser/TmxTerrain.cpp \ tmxparser/TmxTerrainArray.cpp \ tmxparser/TmxText.cpp \ tmxparser/TmxTile.cpp \ tmxparser/TmxTileLayer.cpp \ tmxparser/TmxTileOffset.cpp \ tmxparser/TmxTileset.cpp \ tmxparser/TmxUtil.cpp
NOTE! You only have to list your .cpp and .c files. It will get the header-files
automatically.
Save the file (CTRL + S)
12. Expand DemolitionCrew->app->src->main
Here you will see “java”, “res” and “AndroidManifest.xml”
NOTE! It is easy to accidentally choose the wrong src-folder.
Right click on “DemolitionCrew->app->src->main”
Select New->Folder->Assets Folder. (NOT Directory. the folder option is the one with a android figure on)
A window pops up. Click “Finish”
A new folder is created called “assets”
13. It is OK to breath now!
Now you can minimize the Android studio window and in windows
open up our project folder:
In this folder i place all my assets:
D:\Development\android\DemolitionCrew\app\src\main\assets
Assets are stuff like all your game graphics, sound, music and levels.
In this folder i place all my C++ and C code
D:\Development\android\DemolitionCrew\app\jni\src
Also place all the header files for SDL including SDL_mixer.h, SDL_image.h, SDL_ttf.h and SDL_net.h
I guess there is a better way to do this but I was desperate.
14. Go back to Android Studio
Navigate to DemolitionCrew->app->jni->src in the tree view
If you have a a main.cpp file, it can look something like this.
#include "main.h"
extern "C"
{
using namespace std;
Game *game=nullptr;
int SDL_main(int argc, char* argv[])
{
game = new Game();
game->gameState=gs_LOADING_GAME;
game->init("Game"); // Setting up SDL stuff and open screens
while(game->running())
{
game->update();
game->render();
}
game->clean();
return 0;
}
}
The important stuff here is the extern “C” after the #includes but before everything else
and that you should use SDL_main() instead of plain main()
15. It is time to make a java-class for our game.
Navigate to DemolitionCrew->app->src->main->java
Right click “java” and select “New->Package”. Name it “com.xirbx.games”
Right click “com.xirbx.games” and select “New->File”. Name it “DemolitionCrew.java” (Or your game name)
Double click on DemolitionCrew.java
and paste this text:
package com.xirbx.games;
import org.libsdl.app.SDLActivity;
/**
* A sample wrapper class that just calls SDLActivity
*/
public class DemolitionCrew extends SDLActivity { }
16. Expand the tree view DemolitionCrew->app->src->main
Double Click on AndroidManifest.xml
On line 58 , change from:
<activity android:name="SDLActivity"
To:
<activity android:name="DemolitionCrew"
Save file (CTRL + S)
17. Naming the Game Icon
Expand the tree to this:
DemolitionCrew->app->src->main->res->values
Double click on the “strings.xml”
Change:
<string name="app_name">Game</string>
To:
<string name="app_name">Demolition Crew</string>
This string is where the AndroidManifest.xml gets its game name value from.
I guess you can localize this for different languages.
18. Changing the Icon picture
Expand the tree to this:
DemolitionCrew->app->src->main->res
In each folder that begins with “mipmap” there is a png image called “ic_launcher.png”
Replace those with your own images.
Make sure they are the correct sizes.
I think it is easier to change those from windows and not in Android studio.
19. When all this is done you should be able to build the entire project. (CTRL +F9)
20. Connect a Android device (That is set to developer mode I guess) and press Run (SHIFT +F10)
I hope this tutorial saved you some time. Please check out my games on App store, Google Play
and Nintendo eShop!
Jesper / xirBX AB
