Configuration

Build options, the environment variables the game reads, and the player's settings in savedata.txt.

Three layers configure the game: CMake options when you build it, environment variables when you start it (mostly for testing and diagnostics), and the player's own settings, which the Setup screen edits and savedata.txt keeps. Names below are checked against CMakeLists.txt and src/ as of 2026-11-10.

CMake options

The game's own

CNA options the game gives a default

Standard CMake variables that matter here

Fixed by the game

The game forces these OFF so that only the libraries are built: CNA_BUILD_TESTS, CNA_BUILD_EXAMPLES, CNA_SHARED_LIBRARY (CNA is static: cna-engine links its static modules, and a shared CNA would load twice), and cna-engine's CNA_ENGINE_BUILD_TESTS, CNA_ENGINE_BUILD_EXAMPLES, CNA_ENGINE_WITH_EXTENDED, CNA_ENGINE_WITH_ENHANCED_GRAPHICS, CNA_ENGINE_INSTALL, CNA_ENGINE_PILOT_PROBES and CNA_ENGINE_WARNINGS_AS_ERRORS. CNA itself turns off sharp-runtime's tests.

Where CNA finds its own dependencies

CNA looks for sharp-runtime and easy-gl next to itself; its cache variables CNA_SHARP_RUNTIME_ROOT and CNA_EASYGL_ROOT point elsewhere. easy-gl always adds ../meta-gl beside itself. For Android, Gradle passes CNA_HOME / CNA_ENGINE_HOME from cna.home / cna.engine.home in android/local.properties, else from the environment variables of the same names, else the siblings (Build Guide).

Environment variables

Every variable below is read with std::getenv somewhere in src/. None is needed to play; most exist for tests, comparisons and measurements.

Files and setting overrides

Diagnostics

QA runs

Read by the libraries, not the game: XDG_DATA_HOME, LOCALAPPDATA and HOME decide CNA's per-user folder (Running the Game); SDL_AUDIODRIVER and SDL_VIDEODRIVER are SDL's. The scripts in tools/ have variables of their own (Testing).

Player settings

The Setup screen

Open it from the main menu's Setup button or from Setup in the pause menu; Return or Esc leaves it. Every change is saved at once (a slider when you let it go) and applies at once, except Textures, which applies at the next start. From top to bottom (InputPad.cpp):

The nickname, the language, the volume sliders, 3D terrain, 3D effects, frame rate and textures are Galaxy Eggbert additions (the original took its language, French or English, from the system's; Galaxy does too until the button is pressed); the rest is the original's Setup. Erase progress works as the original's: it resets the whole file to its defaults, every setting and all three players' progress. What the effect levels draw: 3D Effects & Graphics.

savedata.txt keys

A plain key=value text file in the player's folder (src/GalaxyEggbert/Game/SaveData.cpp). Unknown keys are ignored and out-of-range values are clamped or fall back to the default.

soundEnabled=1
jumpRight=1
autoZoom=1
accelActive=0
effectsVolume=100
musicVolume=100
accelSensitivity=50
fullscreen=0
terrainRelief=0
effectsLevel=0
frameRate=60
textureScale=0
selectedGamer=0
gamer0.lives=3
gamer0.missionNumber=0
gamer0.lastWorld=1
gamer0.hasProgress=0
gamer0.doorsUnlocked=0000...   (200 digits)
...

The other player files (resume.txt, demos/, customworlds/) and how progress is checkpointed: Save Data & Resume and SaveData.