FSO for Android — prebuilt libraries & engine builds

Build scripts that cross-compile, for every Android ABI:

• Prebuilt dependency libraries used by FreeSpace Open — FFmpeg, SDL2/SDL3, OpenAL + Oboe, Freetype and shaderc.
• FreeSpace Open itself (Shivansps fork, android-build branch), producing a jniLibs/ tree ready to drop into the FSOwrapper project.

Everything targets Ubuntu 24.04 (x86_64). The Docker images are pinned to linux/amd64 because the Android NDK r29 is a linux-x86_64 toolchain.

Layout

.
├── build_libs.sh            # builds the prebuilt dependency libs
├── build_fso_android.sh     # builds FSO for all ABIs
├── compose.yaml             # both builds, as docker compose services
├── docker_libs/Dockerfile   # image for build_libs.sh       (NDK + SDK baked in)
├── docker_fso/Dockerfile    # image for build_fso_android.sh (NDK baked in)
└── patchs/                  # optional *.patch files applied to FSO (see below)

Build with Docker (recommended)

docker compose build --no-cache
docker compose run --rm libs    # prebuilt dependency libs
docker compose run --rm fso     # FreeSpace Open

Outputs land in your project folder:

Service	Output
libs	prebuilt_android/bin-android-{arm64,x64,arm32,x86}.tar.gz
fso	fso_android/jniLibs/ and fso_android/jniLibs.tar.gz

The NDK (and, for libs, the SDK) are baked into the images at build time, so the runs don't re-download them. The two builds are independent: fso fetches its Android prebuilt libs from the Fso-Android-Prebuilts release, not from prebuilt_android/, so you don't need to run libs first.

On Windows: the Docker path works as-is. The NDK is extracted inside the image (a case-sensitive Linux filesystem).

Applying patches to FSO (optional)

Drop git-style .patch files into patchs/. build_fso_android.sh applies them — in alphabetical order — right after cloning and checking out the android-build branch, before any build starts.

• Number them to control order: 0001-…, 0002-…, etc.
• No .patch files (or no folder) → nothing happens; the build runs normally.

Generate one from a checked-out FSO tree:

git diff > /path/to/repo/patchs/0001-my-change.patch

Keep the folder present — the included README.txt (or a .gitkeep) is enough. The Docker image copies patchs/, and COPY fails if the folder is missing.

Build manually (without Docker)

Build system: Ubuntu 24.04 x86_64.

Dependencies for the prebuilt libraries:

sudo apt-get update && sudo apt-get install -y --no-install-recommends \
  build-essential cmake ninja-build nasm pkg-config \
  meson autoconf automake libtool \
  git curl wget unzip xz-utils ca-certificates file \
  openjdk-17-jdk-headless python3

Dependencies for FSO:

sudo apt-get update && sudo apt-get install -y --no-install-recommends \
  build-essential cmake ninja-build git curl ca-certificates unzip \
  pkg-config libudev-dev libusb-1.0-0-dev

Then run whichever you need:

chmod +x build_libs.sh build_fso_android.sh

./build_libs.sh          # -> prebuilt_android/  (all ABIs)
./build_fso_android.sh   # -> fso_android/jniLibs/  for the FSOwrapper project

Both scripts download the NDK on demand and cache the zip next to themselves. If ANDROID_NDK_HOME already points at a valid NDK, they reuse it and skip the download.