# Crusader Map Renderer

Node web app that renders Crusader maps on the server and streams only finished PNG tiles to the browser.

## Goals

- Keep Crusader source assets server-side.
- Detect maps from `STATIC` and `STATIC_REGRET` automatically.
- Build map render state on demand after the user selects a map.
- Serve large maps as draggable and zoomable image tiles.
- Run locally with Node or inside Docker.

## Local Run

```powershell
cd map_renderer
npm install
npm start
```

Open `http://localhost:3000`.

Viewer behavior:

- drag with the mouse or one finger to pan
- use the scroll wheel to zoom directly at the pointer
- pinch to zoom on touch devices
- toggle roofs and editor-only elements independently before building

The app expects asset folders under the app root:

- `map_renderer/STATIC`
- `map_renderer/STATIC_REGRET`

## Docker Run

The Docker image excludes the Crusader assets on purpose. Mount them at runtime so they stay outside the image and are never served directly to clients.

```powershell
cd map_renderer
docker build -t crusader-map-renderer .
docker run --rm -p 3000:3000 `
  -v ${PWD}/STATIC:/app/STATIC:ro `
  -v ${PWD}/STATIC_REGRET:/app/STATIC_REGRET:ro `
  crusader-map-renderer
```

If only one game is available, mount only that folder.

## Docker Compose

The compose file mounts `STATIC` and `STATIC_REGRET` from the host filesystem into the container as read-only volumes. They are excluded from the image build by `.dockerignore`, so the assets are never copied into the image.

```powershell
cd map_renderer
docker compose up --build
```

## HTTP Surface

- `GET /api/maps` returns the detected catalog.
- `POST /api/builds` starts or reuses a build.
- `GET /api/builds/:id` returns build status.
- `GET /api/maps/:game/:mapId/metadata?buildId=...` returns map bounds and tile settings.
- `GET /api/maps/:game/:mapId/tiles/:tileX/:tileY.png?buildId=...` returns rendered PNG tiles.

No raw Crusader asset files are exposed over HTTP.