Bezeg 2.0
Explore the mathematics of curves, one control point at a time.
Bezeg is an interactive educational app for students and educators. Drag control points, adjust parameters, and follow geometric constructions to see how Bézier curves, splines, and Pythagorean hodograph (PH) curves work.
Open Bezeg 2.0 → · Documentation · Roadmap
Explore
The app brings together 26 interactive demonstrations:
| Topic | What you can explore |
|---|
| Foundations | Bernstein polynomials and their basis functions |
| Bézier curves | De Casteljau's construction, affine transformations, subdivision, extrapolation, and degree elevation |
| Rational curves | Weights, rational constructions, Farin points, and circle pieces |
| Splines | Cⁿ, C¹, C², and G¹ continuity constructions |
| PH curves | Cubic and quintic curves, generating points, and offsets |
| Parameterization | Weighted parameters, spline α parameters, and approximately equal-distance PH sampling |
Controls vary by demonstration. Save examples as browser-local presets, exchange preset files, and export figures as SVG or PNG. Presentation mode gives the graph more room for classroom use.
Bezeg runs in the browser without accounts or a backend. The interface defaults to Slovenian, and English is available from the language selector. See the capability map and UI guide for the full inventory and current limitations.
Run locally
With Node.js 24 (the version in .nvmrc; at least 24.15) and npm installed, run these commands from the project directory:
npm install
npm start
Open localhost:3000/bezeg-2.0/ in your browser. The development server reloads when you edit the source.
The current stack is React, TypeScript, JSXGraph, and Bootstrap, built with Vite and tested with Vitest. See technical architecture for how the app shell, geometry, graph adapters, and presets fit together.
Check your changes
For concise verification with full logs retained, install just and run just --list. just check checks types, runs unit tests once, and builds the app; just unit <test-file> runs a focused unit check. See developer commands for setup, smoke tests, ports, verbose output, and build freshness.
Run the mathematical regression checks:
npm test -- src/bezeg/impl/curve/bezier-evaluation.test.ts
Run the full test suite, and check types (Vite does not type-check):
npm test
npx tsc --noEmit --pretty false
npm test watches for changes in an interactive terminal and runs once in CI or non-interactive shells. See current coverage for the testing status and the performance plan for interaction measurements.
Build and publish
Create the production bundle in build/, and optionally inspect it locally at /bezeg-2.0/:
npm run build
npm run preview
Publish to GitHub Pages using the repository's deployment script:
npm run deploy
The deploy command builds first through predeploy, then publishes build/ using gh-pages to https://github.com/efodx/bezeg-2.0.git. The app is served at /bezeg-2.0/ with an attributed redirect fallback for direct route links. This release is a separate copy: the original app and its site at https://efodx.github.io/bezeg/ remain independent and are not targeted by this script.
The public route base and browser storage namespace change in this release. Presets saved in the original site remain there and do not appear automatically in 2.0. To bring them over, export them from the original site and import that .txt preset file through 2.0's Shrani controls; the established file format and validation remain supported. The 2.0 language choice and saved presets use separate browser-local keys. The GitHub Pages SPA playbook covers routing, assets, and publishing checks.
Contribute
Start with the documentation index and contributor instructions. Contributor documentation is in English.
- Future plan — the agreed direction and open decisions.
- Guardrails — product constraints, mathematical correctness, and engineering practices.
- Roadmap — the sequence of improvements and acceptance criteria.
- Domain glossary — the project's mathematical and technical vocabulary.
The direction is a clearer educational workspace with a prominent graph, understandable controls, responsive interactions, and Bezeg's elderflower identity. Keep changes bounded, preserve mathematical meaning, and match verification to the work.
