Installation

tile57 builds from source with Zig 0.16 — no CMake, no system libraries beyond Zig itself. There are no pre-built binaries.

1. Clone + fetch the submodules

git clone https://github.com/beetlebugorg/tile57.git
cd tile57
git submodule update --init --recursive

The vendored IHO S-101 Portrayal Catalogue comes in as a submodule (under vendor/). It is a build-time dependency: zig build embeds the catalogue (the Lua portrayal rules plus the symbols, line styles, area fills and colour profile) directly into the binary via @embedFile, so the resulting tile57 needs no on-disk catalogue at runtime. Lua 5.4 is vendored under vendor/lua and compiled in, so no system Lua is needed either.

2. Zig 0.16.0 (required)

The engine, the tile57 CLI, and the static library all need Zig 0.16.0. Install it from ziglang.org/download (pin 0.16.0) and put it on your PATH.

3. Build + test

zig build         # builds zig-out/bin/tile57 + libtile57.a
zig build test    # runs the test suite

zig build produces:

Target	What it is
tile57 (zig-out/bin/tile57)	the offline CLI: bake cells/ENC_ROOTs to PMTiles or a chart bundle, and emit portrayal assets.
libtile57.a	the static library behind the C ABI (include/tile57.h).

The engine is also a real Zig package named tile57 (v0.1.0); a Zig consumer adds it as a dependency and uses @import("tile57") — see the Zig API.

Runtime knob

• TILE57_S101_RULES=<dir> — S-101 portrayal rules directory for raw S-57 cells. An override: the rules are embedded in the binary by default, so this is only needed to portray against a different on-disk catalogue (it applies when a caller passes NULL/null for the rules_dir argument). The CLI accepts the same override per-command via --rules <dir> (portrayal) and --catalog <dir> / a positional catalogue path (assets); an explicit path takes precedence over the embedded copy.

Next: Getting Started bakes a chart and fetches a tile.