Building from source

The 1.13 executables are built from the 1dot13/source repository on GitHub. The project is a plain CMake project (minimum CMake 3.20, C++17) that produces 32-bit (x86) Windows executables for up to four applications:

Application	What it is
JA2	The main 1.13 game executable
JA2MAPEDITOR	The 1.13 Map Editor
JA2UB	1.13 for JA2: Unfinished Business
JA2UBMAPEDITOR	The Map Editor for Unfinished Business

Each can be built in one of eight languages: English, German, French, Italian, Polish, Dutch, Russian or Chinese.

The steps below follow the official build instructions from the repository README, which are written for Visual Studio. A command-line alternative and the project's CI setup are covered at the end.

You don't need to build to play

Ready-made all-in-one packages for every language are published on the releases page — see Installation. Building from source is for developers and for anyone who wants to test unreleased changes.

Prerequisites

• Visual Studio 2019 or newer with C++ desktop development and CMake support installed. Visual Studio's built-in CMake integration handles configuration and building; no .sln file is involved.
• Git, either standalone or through Visual Studio's built-in clone support.
• For debugging: a working 1.13 installation including the 1.13 game data (see Debugging below).

Getting the source

Clone the repository from either URL:

https://github.com/1dot13/source.git
git@github.com:1dot13/source.git

You can do this inside Visual Studio (Clone a repository, paste the URL, click Clone, then double-click Folder View in the Solution Explorer) or clone on the command line first and use Open a local folder instead.

First open: the preset template

When Visual Studio opens the folder, it detects the CMake files and runs a first CMake configure. This first run intentionally fails with an error like:

No existing preset was found, copied a preset template to [some_path]

This is normal and happens only once. The build system copies a preset template (CMakePresets.json) from cmake/presets/ into the repository root, where you can customize it without touching version-controlled files.

Selecting a 1dot13 preset

1. Click the configuration dropdown in the toolbar (it initially says x64-Debug) and select Manage configurations.... This makes Visual Studio load the preset file that was just copied. Close the configuration window again.
2. The x64-Debug entry is now replaced by 1dot13 Debug. The template also defines 1dot13 Release and 1dot13 RelWithDebInfo presets.
3. Select the preset you want and open Manage configurations... once more to edit its settings.

Configuring the build

The preset exposes three cache variables you will want to review:

Variable	Default	Meaning
Languages	ENGLISH	Which language builds to configure. Valid choices: ENGLISH, GERMAN, FRENCH, ITALIAN, POLISH, DUTCH, RUSSIAN, CHINESE. Empty ("") configures all.
Applications	JA2	Which executables to configure. Valid choices: JA2, JA2MAPEDITOR, JA2UB, JA2UBMAPEDITOR. Empty ("") configures all.
CMAKE_RUNTIME_OUTPUT_DIRECTORY	.	Where the built executables are placed. For debugging, set this to the path of your JA2 1.13 installation, e.g. C:/Games/JA2.

You can change these through Visual Studio's Manage configurations... window or by editing the copied CMakePresets.json in the repository root directly. The presets use the Ninja generator and build into build/<preset name>.

Two optional CMake switches exist for advanced builds (both off by default):

• LTO_OPTION — enables link-time optimization if the compiler supports it.
• ADDRESS_SANITIZER — enables AddressSanitizer for non-Release builds.

Building

Use Build → Build All. Visual Studio builds every executable you selected via Applications, in every language you selected via Languages, and writes the resulting .exe files to CMAKE_RUNTIME_OUTPUT_DIRECTORY.

Debugging

To debug the game from Visual Studio, CMAKE_RUNTIME_OUTPUT_DIRECTORY must point to a working 1.13 installation — and that includes the full 1.13 game data, not just the original JA2 files. The executable is placed directly in the game folder, so it finds Ja2.ini, the Data-1.13 folder and everything else it needs at startup.

Set up a play install first

The easiest way to get a valid debug target is a normal 1.13 install: original JA2 plus the latest all-in-one release, as described in Installation. Point CMAKE_RUNTIME_OUTPUT_DIRECTORY at that folder and your freshly built executable will run against real game data.

For orientation in the code itself — where tactical, strategic, AI and engine code live — see the code overview.

Building without Visual Studio

Visual Studio is not strictly required: the project's own CI builds from the plain command line using CMake and Ninja with the MSVC compiler. In an x86 Visual Studio developer command environment, the CI runs the equivalent of:

cmake -S . -B build -GNinja -DCMAKE_BUILD_TYPE=RelWithDebInfo -DLanguages=ENGLISH -DApplications=JA2
cmake --build build

Defining Languages and Applications on the command line skips the preset template step, so the configure run does not fail. Note that the build targets 32-bit x86 and links against Windows-only libraries (Bink, Smacker, DbgHelp, Winmm), and the official CI compiles on Windows runners with MSVC.

Continuous integration

The repository builds automatically via GitHub Actions (.github/workflows/build.yml and .github/workflows/build_language.yml):

• Every push to any branch compiles English and German builds of all four applications as a compilation test.
• Pushes to master (and version tags like v*) build all eight languages, assemble full all-in-one packages together with the current gamedir and gamedir-languages content, and update the rolling "Latest (unstable)" pre-release on the releases page.
• Builds for a v* tag are uploaded to that tag's release instead — this is how stable releases are published (see version history).

So even without a local build environment, changes merged into the repository end up in a downloadable build automatically.

Getting help

If you get stuck building, ask on the Bear's Pit Discord or the Bear's Pit forum. If you want to contribute your changes back, see Contributing.

Sources

• README of github.com/1dot13/source (Visual Studio setup instructions)
• CMakeLists.txt from 1dot13/source (CMake 3.20, C++17, build options, libraries)
• cmake/presets/CMakePresets.json and cmake/CopyUserPresetTemplate.cmake from 1dot13/source (preset names, cache variables, defaults)
• .github/workflows/build.yml and .github/workflows/build_language.yml from 1dot13/source (CI build and release process)