# Roadmap

Open ideas for the playground frontend. Tick a box when done.

## Quick wins

- [ ] **Labyrinth grid size crash**: `labyrinth.component.html` still binds `[gridRows]`; typed sizes above the max crash the page. Same fix as pathfinding (clamp in code, drop the binding).
- [ ] **Fourier circles slider thumb**: at "Circles: 256" the thumb sits near the left end, like at 30. Check `max`/value binding of the circles `mat-slider` (seen 2026-10-14, not verified).
- [ ] **Lighthouse gate**: add an `assert` block to `lighthouserc.json` (e.g. performance, accessibility, SEO >= 0.9). Today CI runs the audit but never fails.
  Note: the `@lhci/cli` → lighthouse 13 override in `package.json` is only safe without `assert`. Check it again before you add one.
- [ ] **robots.txt + sitemap.xml**: static files in `public/`, listing all routes from `app.routes.ts`.
- [ ] **SEO per algorithm page**: all algorithm routes use `data: { seo: 'ALGORITHMS' }`. Give each one its own key and add `SEO.<KEY>.TITLE` / `DESCRIPTION` to `en.json` and `de.json`.
- [ ] **nginx security headers**: no CSP, `X-Content-Type-Options`, `Referrer-Policy`, `frame-ancestors` in `nginx.conf` (gzip done). First check with `curl -I https://andreas-dahm.eu/` if the reverse proxy already sets them.

## Tests

- [ ] `seo.service.ts`: spec for title/meta update on route change and language change.
- [ ] **Cloth ICM drop specs near timeout**: drop specs in `cloth-icm-solver.spec.ts` take 2.5-3 s each vs Vitest's 5 s default; give them an explicit timeout before a slow CI runner fails them.
- [ ] Pure logic without specs: `pathfinding-animator.ts`, cloth and pendulum GPU strategies (the math around them, not the shaders), `fractal3d`.

## Features

- [ ] **Cloth ICM next steps** (page `algorithms/cloth-icm`, CPU; detection + contours in `collision/`, one response file per paper in `response/`):
  - [x] **Fold flutter damping**: drop cloth never settled (fold vertices flutter at 0.6-1.0 m/s). Done 2026-11-01: cause was the proximity push on folds lying on the ground (push out, next frame stretch constraints pull back, ~1 m/s chatter), not XPBD. Velocity smoothing (neighbour mean) + proximity velocity clamp, drop scene only, drop gap 0.035 -> 0.02: after landing (frames 600-900) max speed median 0.107, p90 0.207 (was 1.2 / 2.0 at 35x35), mean 0.012, same fall and drape, landing frame 20 as before, 11-12 ms/frame headless on 40x40 (was 10.3 on 35x35). Tangled scene bit-identical.
  - [ ] **Bridson 2002**: CCD + velocity-level repulsion, so fast motion cannot jump through the gap; allows a finer drop grid. Large.
  - [ ] **Papers extending ICM**: Ye et al. 2017 (untangling via discrete collision detection), Buffet et al. 2019 (implicit untangling, layered clothing). New `response/` file + scene each. Medium per paper.
  - [ ] **GPU port**: detection on the GPU, contours stay on the CPU (serial walk). Very large.
- [ ] **Cloth ICM drop scene** (state): hits mostly solved, cloth settles. Drop scene 40x40 (spacing 0.145, 5.7 m cloth, user-set), gap 0.02, initial spin 1.5 rad/s around y, one mid-frame proximity re-detection (every 5), velocity smoothing + proximity velocity clamp. Frames 100-240: ICM on avg 1.0 hits per frame (59 % of frames at 0, max 10), ICM off avg 9.8 (max 43), bounded over 900 frames (max 92 after frame 150). Settled: max vertex speed median 0.107 / p90 0.207 m/s (frames 600-900, ICM on; target was 0.1; ICM off median 0.089), mean 0.012, rare snaps to 0.6-0.7. 11.4 ms/frame headless (60 fps budget 16.7). Spin sweep (values above ~0.75 rad/s are capped at the rim to 3 m/s in the first frame; ICM on / off hits, ratio): none 0.31 / 3.9 (12.7x); 0.1 2.6 / 4.3; 0.4 3.5 / 5.8; 0.7 1.3 / 5.1; 1.5 1.0 / 9.8 (chosen, most hits); 3 0.7 / 7.2 (rest speed worse). Finer grids or a gap >= 0.04 made ICM off blow up before the fix (not re-measured). Next: Bridson 2002 CCD + velocity repulsion.
- [ ] **Shareable demo state**: keep demo settings in query params (fractal zoom/center, sorting algorithm, seeds). Opening the link restores the view.
- [ ] **New algorithm demos** (pattern: route + `RouterConstants` + `AlgorithmsService` entry + i18n + information panel):
  - [x] Boids / flocking (GPU path like cloth)
  - [x] **Physarum** (slime mold transport networks, trail map on GPU compute, CPU fallback)
  - [ ] Boids 3D (later, 2D done)
  - [x] **Voronoi / Delaunay** (Bowyer-Watson, CPU + Canvas 2D)
  - [x] A* vs Dijkstra side by side (reuse pathfinding)
  - [x] Fourier epicycles
  - [x] Reaction-diffusion (Gray-Scott) shader (reuse the fractal shader setup)
  - [x] **Lenia** (continuous Game of Life, shader ping-pong like Gray-Scott)
  - [x] **Fluid (Stable Fluids)** (velocity, pressure and dye shader ping-pong like Lenia)
  - [x] **Cloth self-collision (ICM)** (Volino and Magnenat-Thalmann 2006, CPU: BVH with normal-cone culling, contour tracing, intersection contour minimization)
  - [x] **Ant colony** (ACO on TSP, CPU + Canvas 2D)