OpenTTD-patches/os/emscripten
Jonathan G Rennison cf4cf5c08f Codechange: vendor the nlohmann-json library (#11290)
(cherry picked from commit ba67f39db6)

# Conflicts:
#	.github/workflows/ci-build.yml
#	CMakeLists.txt
#	COMPILING.md
#	src/os/macosx/survey_osx.cpp
#	src/os/windows/survey_win.cpp
#	src/script/api/script_admin.cpp
#	src/script/api/script_event_types.cpp
#	src/tests/test_script_admin.cpp
2023-11-17 19:20:35 +00:00
..
cmake Codechange: vendor the nlohmann-json library (#11290) 2023-11-17 19:20:35 +00:00
Dockerfile Codechange: vendor the nlohmann-json library (#11290) 2023-11-17 19:20:35 +00:00
emsdk-liblzma.patch Change: [CI] update emscripten and liblzma to the latest version (#10757) 2023-05-02 23:12:52 +02:00
loading.png Add: support for emscripten (play-OpenTTD-in-the-browser) 2020-12-15 15:46:39 +01:00
pre.js Add: [Emscripten] Support for bootstrapping 2023-08-31 12:59:12 +02:00
README.md Codechange: vendor the nlohmann-json library (#11290) 2023-11-17 19:20:35 +00:00
shell.html Add: [Emscripten] Support for bootstrapping 2023-08-31 12:59:12 +02:00

How to build with Emscripten

Please use docker with the supplied Dockerfile to build for emscripten. It takes care of a few things:

  • Use a version of emscripten we know works
  • Patch in LibLZMA support (as this is not supported by upstream)

First, build the docker image by navigating in the folder this README.md is in, and executing:

  docker build -t emsdk-openttd .

Next, navigate back to the root folder of this project.

Now we build the host tools first:

  mkdir build-host
  docker run -it --rm -v $(pwd):$(pwd) -u $(id -u):$(id -g) --workdir $(pwd)/build-host emsdk-openttd cmake .. -DOPTION_TOOLS_ONLY=ON
  docker run -it --rm -v $(pwd):$(pwd) -u $(id -u):$(id -g) --workdir $(pwd)/build-host emsdk-openttd make -j$(nproc) tools

Finally, we build the actual game:

  mkdir build
  docker run -it --rm -v $(pwd):$(pwd) -u $(id -u):$(id -g) --workdir $(pwd)/build emsdk-openttd emcmake cmake .. -DHOST_BINARY_DIR=../build-host -DCMAKE_BUILD_TYPE=Release -DOPTION_USE_ASSERTS=OFF
  docker run -it --rm -v $(pwd):$(pwd) -u $(id -u):$(id -g) --workdir $(pwd)/build emsdk-openttd emmake make -j$(nproc)

In the build folder you will now see openttd.html.

To run it locally, you would have to start a local webserver; something like:

  cd build
  python3 -m http.server

You can now play the game via http://127.0.0.1:8000/openttd.html .