Building for Linux

This document describes the process to build Ocean on Linux.

1 Prerequisites

• General prerequisites listed on the main page
• Python 3.10 or higher, plus the build scripts' dependencies: pip install -r build/python/requirements.txt
• Currently some packages will have to be installed using the package manager of your distribution (example commands and package names given below are for Fedora and Ubuntu, but they should be similar for other distributions): ``` # Fedora sudo dnf install libX11-devel-1.7.0-9.el9.x86_64 \ gtk3-devel-3.24.31-2.el9.x86_64 \ mesa-libGL-devel \ libgudev-devel \ xz-devel

# Ubuntu sudo apt-get install libx11-dev libudev-dev liblzma-dev libgl1-mesa-dev libxcb-glx0-dev ```

2 Building the third-party libraries

The third-party libraries are built using the Python-based build system. It handles fetching, patching, and building all dependencies with DAG-based parallel builds.

cd /path/to/ocean

# Build for every target this host supports (debug + release, static)
python build/python/build_ocean_3rdparty.py

# Build release only
python build/python/build_ocean_3rdparty.py --config release

# Include optional libraries (e.g., OpenCV)
python build/python/build_ocean_3rdparty.py --with opencv

# Show build plan without building
python build/python/build_ocean_3rdparty.py --dry-run

Once the build is complete, the installed libraries can be found in ocean_3rdparty/install/. Each library is a complete, relocatable CMake install prefix at <target>/<library>/, for example linux_x86_64_static/zlib/include/zlib.h and linux_x86_64_static/zlib/lib/libz.a. Release targets have no suffix; debug targets add _debug. On ARM64 systems, paths use arm64 instead of x86_64. On distributions that install into lib64 (Fedora, RHEL and derivatives) the prefix contains lib64/ rather than lib/, since the tree is copied as CMake produced it.

Passing --for-external-integration produces a different, flattened layout intended for non-CMake build systems, with headers shared across architectures: <library>/h/<platform>/ and <library>/lib/<target>/.

Run python build/python/build_ocean_3rdparty.py --help to see all available options.

Note: The build system displays a real-time TUI with progress for all parallel build jobs. Use --log-level verbose to see detailed build output instead.

3 Building Ocean

Ocean is built using a Python build script that invokes CMake with the correct configuration.

cd /path/to/ocean

# Build Ocean using the Python 3P layout
python build/python/build_ocean.py
# Build for a specific configuration
python build/python/build_ocean.py --config release

# Specify custom directories
python build/python/build_ocean.py \
    --build-dir "${HOME}/build_ocean" \
    --install-dir "${HOME}/install_ocean" \
    --third-party-dir /path/to/ocean_3rdparty/install

# Show build plan without building
python build/python/build_ocean.py --dry-run

Once the build is complete, the compiled binaries can be found in ocean_install/linux_x86_64_static (release) and .../linux_x86_64_static_debug (or linux_arm64_static* on ARM64 systems).

Run python build/python/build_ocean.py --help to see all available options.

CMake options for Linux x86_64

To disable AVX2, pass the option when invoking CMake directly (see Using CMake Directly):

cmake -S . -B build_linux \
    -DOCEAN_ENABLE_AVX2=OFF \
    -DCMAKE_BUILD_TYPE=Release \
    -DBUILD_SHARED_LIBS=OFF \
    -DOCEAN_THIRD_PARTY_ROOT=./ocean_3rdparty/install

Note: This option only affects Ocean's own code. Third-party libraries are built separately and do not use AVX2 instructions.

Using CMake Directly

Alternatively, you can invoke CMake directly:

cd /path/to/ocean

# Configure and build using CMake
cmake -S . -B build_linux \
    -DCMAKE_BUILD_TYPE=Release \
    -DBUILD_SHARED_LIBS=OFF \
    -DOCEAN_THIRD_PARTY_ROOT=./ocean_3rdparty/install

cmake --build build_linux --target install -j