# gadm-boundaries

Native C++ boundaries batch generator for the GADM pipeline.  
Uses GDAL/GEOS/PROJ for **10–100× speedup** over the TypeScript pipeline on geometry union + GHS raster enrichment.

## Prerequisites

| Tool | Version |
|------|---------|
| CMake | ≥ 3.20 |
| C++ compiler | C++20 (MSVC, GCC, or Clang) |
| vcpkg | Latest (set `VCPKG_ROOT` env var) |

## Setup

```bash
# Install native dependencies (one-time)
vcpkg install
```

## Build

```bash
# Release (Ninja)
cmake --preset vcpkg
cmake --build build --config Release

# Windows MSVC
cmake --preset vcpkg-win
cmake --build build --config Release

# Debug
cmake --preset dev
cmake --build build/dev
```

## Usage

```bash
# All countries, all levels
./build/boundaries --country=all

# Single country, specific level
./build/boundaries --country=DEU --level=0

# Force regeneration (ignore cache)
./build/boundaries --country=NGA --force
```

Output goes to `cache/gadm/boundary_{code}_{level}.json` — drop-in replacement for the TS pipeline.

## Architecture

See [docs/cpp-port.md](../docs/cpp-port.md) for the full spec.

```
src/
├── main.cpp          # CLI entry, country loop, cache logic
├── gpkg_reader.h/cpp # GeoPackage → features (OGR)
├── geo_merge.h/cpp   # Geometry union (GEOS)
├── ghs_enrich.h/cpp  # GeoTIFF raster sampling + PIP
├── pip.h             # Inline ray-casting point-in-polygon
└── types.h           # BoundaryFeature, BoundaryResult structs
```