# OpenDana OpenDana is a native, moddable reimplementation of *Solomon's Key 2*, the NES puzzle game also released as *Fire 'n Ice*. It is written in C11 with a deterministic core, runs on Linux, Windows and macOS, and adds a built-in level editor, save states, gamepad support and a mod system. OpenDana does not include any of the original game's content. To play, you need **your own copy of the European ROM** (see [Requirements / legal](#requirements--legal)). On first start, OpenDana reads it once to extract the game's data (levels, graphics, text, music and sound effects) into a local folder. It never runs code from the ROM, does not emulate the console, does not copy or upload the ROM, and does not need it again afterwards. ## Features - A deterministic C11 core with no SDL dependency; the SDL2 front end is a thin layer on top. - A level editor and a level catalogue, both driven with the mouse. - Save states in numbered slots, a mute key, fullscreen and gamepad support. - Mods: a content package of JSON and PNG files that you can replace or overlay, with schemas and a validator. - A command-line API for external tools: validate, play and render a level file. ## Requirements / legal OpenDana is an independent, unofficial project. It is not affiliated with or endorsed by the owners of the original game, and it contains **no** ROM, no graphics, no text, no music, no sound effects and no level data of that game. The names and trademarks of the original belong to their owners (see [`NOTICE`](NOTICE)). To play you need a legally obtained copy of the ROM of the European release of *Solomon's Key 2 / Fire 'n Ice*. OpenDana accepts only the file whose SHA-256 is: ``` 853646c50889dfb7a74c2acf7cf3b76f42d044745433f706dca33f47d826cd1d ``` Check yours with `sha256sum FILE` (Linux), `shasum -a 256 FILE` (macOS) or `certutil -hashfile FILE SHA256` (Windows). Any other file is refused without changing anything. ## Install Download a release and pick one: | Package | How to start | |---|---| | Linux **TAR** (`opendana-X.Y.Z-Linux-x86_64.tar.gz`) | unpack it anywhere and run `bin/opendana`; keep `bin/` and `lib/` together | | Linux **AppImage** | `chmod +x` the file and run it | | Windows **ZIP** (`opendana-X.Y.Z-Windows-x86_64.zip`) | unpack it anywhere and run `bin\opendana.exe`; keep `SDL2.dll` next to it | | macOS **DMG** (`opendana-X.Y.Z-macOS-universal.dmg`) | open it and drag `OpenDana.app` to Applications; the first time, **right click it and choose Open**, because the app is signed ad hoc and is not notarized by Apple | The Linux and Windows packages are for 64-bit x86. The macOS disk image is universal: the app holds an x86_64 and an arm64 build. The arm64 half is compiled but has not been run on Apple Silicon, so it is untested. Each package carries the licence, the third-party notices and the corresponding source code. Verify a download with `sha256sum -c SHA256SUMS` (on macOS, `shasum -a 256 -c SHA256SUMS`). `opendana --version` prints the version and the commit it was built from. ## First run: import your ROM The first start shows an import screen. Press **Choose ROM...** and pick your file, or **drag the ROM onto the window**. If your system has no file chooser, or as soon as you start typing, the screen shows a field for the path. You can also import from a terminal: ```sh opendana --import-rom /path/to/your-rom.nes opendana /path/to/your-rom.nes # import, then start ``` The import is deterministic and all-or-nothing: if it fails, nothing is left half written. It is checked against a manifest of file hashes built into the program. The ROM is read once and never copied; afterwards you do not need it. If a later version of OpenDana needs different content, the game tells you and asks you to import again. Where things are stored: | | Linux | Windows | macOS | |---|---|---|---| | imported content | `$XDG_DATA_HOME/opendana/content/base` (default `~/.local/share/opendana/...`) | `%LOCALAPPDATA%\opendana\content\base` | `~/Library/Application Support/opendana/content/base` | | saves, states, screenshots | `$XDG_DATA_HOME/opendana/` | `%LOCALAPPDATA%\opendana\` | `~/Library/Application Support/opendana/` | | settings (`settings.ini`) | `$XDG_CONFIG_HOME/opendana/` (default `~/.config/...`) | `%APPDATA%\opendana\` | `~/Library/Application Support/opendana/` | `--content DIR`, `--save FILE` and `--settings FILE` use other locations. ## Controls Keyboard to NES pad: | Key | Pad | |---|---| | Arrows | D-pad | | `Z` or `Space` | A | | `X` | B | | `Enter` | START | | Right `Shift` | SELECT | Interface keys (they never reach the simulation): | Key | Action | |---|---| | `Esc` | menu | | `F1` | controls screen | | `F2` | console RESET | | `F5` / `F9` | save / load a state in the current slot | | `F6` / `F7` | previous / next slot | | `M` | mute | | `F11` | fullscreen | | `F12` | screenshot | Gamepads work through SDL's game controller mapping. `opendana --help` lists every option. ## Level editor `opendana --editor` (or **Levels** in the menu) opens the editor: a toolbar, a palette of materials, mouse painting (left click paints, right click erases, middle click picks, the wheel changes material), undo and redo (`Ctrl+Z`, `Ctrl+Y`), `Ctrl+S` to save and `F5` to test the level in the same window. The catalogue stores each level as a JSON file and lets you play, edit, duplicate, delete, import and export levels. ## Mods Everything the game shows comes from a content package of JSON and PNG files (schemas in [`schema/`](schema)). A mod is a directory with a `mod.json` that adds or replaces some of those files; mods are layered on top of the package and the last one wins. ```sh opendana --mod example # the example mod, mods/example opendana --mod /path/to/my-mod # any directory with a mod.json opendana --validate /path/to/my-mod # check a package, a mod or a level file opendana --play-level my-level.json --round 3 opendana --render-level my-level.json --out level.png ``` A mod never needs to contain anything of the original game, and yours must not. Read the guide: [`docs/MODDING.md`](docs/MODDING.md). ## Building from source You need a C11 compiler, CMake 3.16 or later and the SDL2 development files (for example `libsdl2-dev`). Nothing is downloaded during the build. ```sh bash build.sh # build/opendana SDL2_DIR=/path/to/sdl2 bash build.sh # use an SDL2 installed elsewhere ``` This is the same on Linux and macOS (on macOS, point `SDL2_DIR` at an installed SDL2 prefix, or configure with CMake and pass `-DOD_SDL2_FRAMEWORK=/path/to/SDL2.framework` to link a framework). On Windows the packages are cross-compiled with MinGW-w64. This also builds `build/libopendana_core.a` (the core, no SDL) and the unit test runner. To check your clone: ```sh build/opendana_tests_public --category unit ``` See [`CONTRIBUTING.md`](CONTRIBUTING.md) for the rest of the tests and the rules for contributions, and [`docs/RELEASE.md`](docs/RELEASE.md) for how the packages are built. ## Repository layout ``` include/opendana/ public headers of the core src/core/ deterministic C11 core: game, scenes, flow, audio, content src/ext/ extension layer without SDL: editor, catalogue, states, settings src/import/ importer of the user's ROM src/platform/ portable paths src/render/ presentation and PNG writer src/app/ SDL2 layer: window, input, audio, interface schema/ JSON schemas of the content package and of mods mods/example/ example mod packaging/ package scripts, icon, notices tests/, tools/ tests and tools external/ vendored libraries with their licences ``` ## Licence The code is free software under the **GNU General Public License, version 3 or later**: see [`LICENSE`](LICENSE). Third-party components and their licences are in [`NOTICE`](NOTICE). The imported game content is yours, for personal use, and is never part of this project.