gem-hunter

A modernized build of the Zod Engine — the open-source remake of the 1996 Bitmap Brothers real-time strategy game Z — brought up to date to build and play cleanly on current macOS (Apple Silicon), Linux, and Windows, on native SDL3.

This is a fork of the Zod Engine by Michael Bok / Nighsoft (http://zod.sourceforge.net/), originally released under the GPLv3. All the original gameplay is intact; this fork focuses on getting it building and running well on modern systems.

• Ported from SDL 1.2 all the way to native SDL3 — no compatibility shims. Modern SDL3 rendering, input, threads, and SDL3_mixer (MIX_ API) audio throughout; the window/framebuffer and audio layers are honest native modules (zvideo, zaudio), not faked-SDL facades.
• Fixed a family of rendering regressions introduced along the way (sprites that silently failed to draw: zone flags, the resume banner, rock / grenade animations, vehicles, portrait overlays — a negative-source-rect clipping bug; plus black boxes around rotated alpha sprites from an SDL3 bool-return change).
• Fixed input/gameplay issues: fullscreen cursor offset (window→render coordinate mapping) and contested zone flags strobing between teams.
• Modern scaled-framebuffer rendering: the game renders to a logical framebuffer and is GPU-scaled crisp to a large, HiDPI/Retina-aware window (no more tiny, OS-blurred output). Smooth scaling by default; optional knobs via ZOD_FILTER, ZOD_INTEGER, ZOD_SCANLINES.
• Two-finger trackpad panning of the map.
• Dropped the MySQL dependency (it was only for the old online master-server); the binary now needs only SDL3 + extensions.
• Installable: finds its data when installed to a prefix, and launches straight into the single-player campaign with no arguments.
• CMake build + this README + CI.

brew install fenio/tap/zod
zod

This pulls a prebuilt binary (a bottle) when one is available for your arch, otherwise it builds from source. zod with no arguments launches the single-player campaign. (Equivalently: brew tap fenio/tap && brew install zod.)

scoop bucket add fenio https://github.com/fenio/scoop-bucket
scoop install zod
zod

Or grab the zod-windows-x86_64.zip straight from the Releases page and run zod.exe.

⚠️ The Windows build is experimental — it's confirmed to run, but a few input quirks are still being smoothed out. Reports and fixes welcome.

See Build & run below.

Dependencies: a C++ compiler, CMake, pkg-config, and SDL3 with the image, mixer, and ttf extensions. Note that the audio uses SDL3_mixer's new track-based MIX_ API, which needs SDL3_mixer ≥ 3.2.4 — fine on Homebrew and MSYS2, but only in very recent Linux distros (see the Linux note below).

macOS (Homebrew):

brew install cmake pkg-config sdl3 sdl3_image sdl3_mixer sdl3_ttf

Windows (MSYS2 / MinGW):

pacman -S mingw-w64-x86_64-gcc mingw-w64-x86_64-cmake mingw-w64-x86_64-ninja \
  mingw-w64-x86_64-pkgconf mingw-w64-x86_64-sdl3 mingw-w64-x86_64-sdl3-image \
  mingw-w64-x86_64-sdl3-mixer mingw-w64-x86_64-sdl3-ttf

Debian / Ubuntu / Fedora: SDL3 itself is widely packaged now (libsdl3-dev … on apt, SDL3-devel … on dnf), but the MIX_-API SDL3_mixer (3.2.4) only reached distro repos very recently (Ubuntu 26.04, Fedora 42+). On older releases, install SDL3 + SDL3_image + SDL3_ttf from your package manager and build SDL3_mixer from its upstream release — the CI workflow shows the exact steps (it builds SDL3_mixer 3.2.4 from source inside an Ubuntu container).

Then:

cmake -S . -B build
cmake --build build -j
./build/zod            # run in place (assets are found next to the binary)

Install system-wide (optional):

sudo cmake --install build           # -> <prefix>/bin/zod, <prefix>/share/zod
zod                                  # plays the campaign

Running with no arguments starts a local single-player campaign (you on red vs. a blue bot, all 34 levels in order). Useful flags:

Controls: left-click selects; right-click moves/attacks in modern mouse mode; right-drag, middle-drag, two-finger scroll, or arrow keys pans the map. Capture a zone by walking a unit onto its flag; crew a neutral (grey) vehicle by sending a grunt onto it. Alt+Enter toggles borderless fullscreen. Press Y to toggle render smoothing (see below). The game starts paused — click the centre "Click to Start / Resume" banner to begin.

Classic mouse (original-Z style, default): a plain left-click with units selected issues the order and ends the interaction, like the 1996 game — clicks on your own units and drags still select, right-click cancels the selection. Toggle it (and render smoothing) in the in-game Options menu — the choice persists in ~/.zod_prefs; ZOD_CLASSIC_MOUSE=0 / ZOD_SMOOTH=0 still override per launch.

Render smoothing: a purely visual layer (on by default) eases unit movement through its position-correction "snaps" and gives stationary vehicles a smooth idle engine bob. It never affects gameplay. Toggle live with Y, or start with it off via ZOD_SMOOTH=0.

Reporting a bug (zod_diag.log): the game always writes a diagnostic log — zod_diag.log, next to the binary on Windows or in your home folder on macOS/Linux. It auto-records suspicious events as they happen (a move order to an unreachable spot, a unit stuck with no progress, a match that can't end). If a specific unit misbehaves, select it and press F12 (or \ where the OS reserves F12, e.g. macOS) to append its full state — orders, target, owner, whether it can move, crewed vs. driverless — plus a per-team unit census. Attach that file to a bug report; it's far more useful than a screenshot for movement/AI issues.

Pathfinding debug log: to collect evidence when a unit gets stuck or takes a weird route, run with ZOD_PATHLOG=1 — the engine writes zod_path.log recording every move order, A* request/result (with search time), the chosen route, units blocked by impassable terrain, arrivals, and a STUCK line when a unit makes no progress on a move order for 5 seconds. ZOD_PATHLOG=2 adds leg-by-leg progress; ZOD_PATHLOG_FILE overrides the output file (- = stdout). Observation only — it reads movement state but never changes it, and costs nothing when off. For unattended stress-testing, ZOD_BOT_FUZZ=1 makes bots additionally order random units to random map coordinates (reachable or not) — combined with the log it's a pathfinding fuzz harness.

The build also produces zod_mapgen, a standalone skirmish map generator — every seed is a different map:

./build/zod_mapgen -e 2 -s 7 -o maps/random.map
./build/zod -m maps/random.map -t red -b blue -b green -n Player -r 800x600 -w

Generated maps have a fort + starting squad per team, capturable zones with neutral factories/radar/repair, lakes, roads, and rock fields. Run it from the game directory — it reads the palette info and learns its shoreline/road/ground tile usage from the shipped campaign maps, and it guarantees every flag and unit is reachable (vehicle-checked) before writing the file.

• The Zod Engine is by Michael Bok / Nighsoft — this is an SDL3 modernization of their open-source remake of the 1996 Bitmap Brothers RTS Z.
• Splash screen artwork by v2elite.

GPLv3 — see LICENSE. The Zod Engine is © its original authors (Michael Bok / Nighsoft); this fork is distributed under the same license.