User Guide

User guide

Build

OpenCaptive requires CMake 3.20+, a C17 compiler, SDL3 and zlib.

cmake -S . -B build -G Ninja
cmake --build build
ctest --test-dir build --output-on-failure

Use a separate build-release directory with -DCMAKE_BUILD_TYPE=Release for a shipping-style test run. Tests explicitly keep assertions enabled in Release builds.

Launch and data checks

./build/opencaptive --data /path/to/your/media --verify-data all
./build/opencaptive --data /path/to/your/media --game captive
./build/opencaptive --data /path/to/your/media --game liberation

--verify-data captive, --verify-data liberation and --verify-data all perform read-only SHA-256 verification. A successful check means that the known content required by the current loader was found; it does not claim that every original gameplay system is implemented.

Archives may be stored directly in the chosen directory. The loader scans archive entries and loose files by their bytes, so repacking or renaming media does not change its identity.

Captive controls

Input	Action
W/S or arrows	Walk forward/back
A/D or left/right	Turn
Q/E	Strafe
Space	Attack with selected droid
F	Open/interact with the facing object
1–4	Choose droid
I / T / M	Inventory / terminal / map overlay
, / .	Use up/down stairs
F5 / F9	Save / load Captive state
F10	Open runtime graphics and cheat options
Escape	Return to menu

Closed doors block movement and line of sight. Face a normal door and use F. Generators are mission objectives; destroying all generated generators advances the campaign. A direct attack or enemy shot cannot cross a wall or closed door.

Liberation status and controls

Verified CD32 presentation data is decoded for Liberation's opening and city frame. Press any key to advance from the opening to the city frame. The old procedural city/interior controls are not presented as a playable Liberation implementation: their generated logic is not the original game's logic and no longer produces substitute graphics. F10 still opens the runtime options.

Runtime options and cheats

Press F10 during either game to pause the live simulation and open the runtime popup. It can switch the experimental enhanced Captive viewport, scanlines, CRT curvature, bilinear output filtering, brightness, music and SFX immediately. The same popup has explicit cheat switches for god mode, infinite energy and completing the current objective. Escape or F10 closes it. The start-menu settings page also exposes music and SFX enablement for the next game session. Cheats are deliberately visible and opt-in; they are not activated by command-line defaults.

Saves

Captive saves contain the map-cell state, droids, money, generator progress, creatures and puzzle state. Loading is transactional: malformed or truncated saves are rejected without overwriting the running game.

The save format is intentionally versioned. Newer engine versions can reject old experimental saves rather than interpreting them incorrectly. Liberation uses a separate versioned save format for its city and interior state. Use F5 and F9 while playing Liberation; it does not reuse Captive's incompatible dungeon save format.

Useful diagnostics

For a noninteractive smoke start on a Unix-like system:

SDL_VIDEODRIVER=dummy SDL_AUDIODRIVER=dummy \
  timeout 5 ./build/opencaptive --data /path/to/your/media --game captive

The expected result is a timeout after the game loop has started, with log lines for texture loading and verified game startup. It is not a gameplay-completion test.