# Credits & licences · ABT01 Tools v1.1

## Open-source code bundled in the app
| Library | Use | Licence |
|---|---|---|
| [three.js](https://threejs.org) | 3D preview, OrbitControls | MIT |
| [opentype.js](https://opentype.js.org) | Reading fonts, text → outlines | MIT |
| [earcut](https://github.com/mapbox/earcut) (Mapbox) | Polygon triangulation for STL / 3MF | ISC |
| [fflate](https://github.com/101arrowz/fflate) | ZIP for 3MF packages and multi-sheet downloads | MIT |
| [polygon-clipping](https://github.com/mfogel/polygon-clipping) (Mike Fogel) | Boolean ops for stencil bridges (union / difference / xor) | MIT |
| [Vite](https://vitejs.dev), [TypeScript](https://www.typescriptlang.org), [Vitest](https://vitest.dev) | Build and tests (dev only) | MIT / Apache-2.0 |

## Fonts (in `public/fonts/`)
- **Archivo Black** · Omnibus-Type · SIL Open Font License 1.1
- **Bebas Neue** · Dharma Type · SIL Open Font License 1.1
- **Hershey single-stroke fonts** (`public/fonts/hershey/*.jhf`: futural, futuram, scripts, timesr) · Dr. A. V. Hershey, U.S. National Bureau of Standards. Free to use under the Hershey font licence: the original fonts were developed by Dr. A. V. Hershey while working at the U.S. National Bureau of Standards, and the .jhf files come from the hershey-fonts package by Kamal Mostafa. Only the font data is used; the parser and layout in `src/generators/hershey.ts` are our own.
- UI fonts Inter, Space Grotesk, JetBrains Mono load from Google Fonts (OFL 1.1).

## Projects that may be reused with credit (MIT)
- **SVGnest** (Jack Qiao) · nesting. v1 uses its own simple rectangle (shelf) nesting; true-shape nesting with SVGnest is planned.
- **Joinery** (Florian Fischer) · joints for laser parts. Credited as reference for joint ideas; no code copied in v1.
- **LaserCutMazes** · maze ideas. The v1 maze code (recursive backtracker + exact wall outline tracing) is our own.
- **VectorRuler** · planned for the ruler tool (not in v1).

## v1.1 tools: where ideas came from
- **Single-line text**: our own Hershey (.jhf) parser and layout.
- **Stencils**: our own island detection and automatic bridges, built on polygon-clipping.
- **Jigsaw**: our own tab geometry (neck plus round head) with shared edges. Draradech's jigsaw tool was looked at as an idea only; no code was used.
- **Café set, gaskets/washers/drill guides, packaging dielines**: our own geometry.
- **G-code and EPS writers**: our own code. Router tool offsets use our own miter offset (`src/core/offset.ts`).
- None of SVGnest, Joinery, LaserCutMazes or VectorRuler code is used in v1.1, so no new credits are needed for them.

## Ideas only, no code copied
- **Boxes.py**, **MakerCase** and **Templatemaker** inspired features. Licences don't allow reuse here, so the finger-joint box and the packaging templates (tuck-end carton, mailer) are written from scratch.
- The gear maths is the standard involute construction (textbook geometry). Hessmer and Leary gear tools were used as reference only.