WildQuant — ashutosh-shinde.github.io

Some curious explorations in mathematics and wildlife, by Ashutosh Shinde.

The whole background is drawn live in code on a blackboard: chalk equations, animals and a stick-figure explorer. There are no videos or background images. Each section of the home page has its own scene. Scrolling to the next section dissolves one scene into chalk dust that re-forms as the next, and the scroll position is the timeline: stop half-way and you see the half-way state.

Preview on your computer

cd ashutosh-shinde.github.io
python3 -m http.server 8000

Then open http://localhost:8000. Use a local server: opening index.html by double-click blocks the fonts.

Where things are

What	File
Home page text, links, section texts, the comment box	index.html
About page (blank for now)	about/index.html
Blogs: title and the list of stories (the boxes are made by tools/publish/build.py)	blogs/index.html
Blogs list: the background of names (Himalayan peaks and routes, glaciers, India's parks and sanctuaries: particles in a box) and the explorer strip at the bottom	js/scenes/gearbox.js, js/lib/strip.js
Simulations: the list of collections and their numbered cards	simulations/index.html
A simulation page (one folder each), e.g. the discrete-time logistic model	simulations/population-dynamics/discrete-logistic/index.html
A simulation's maths and controls (one file per simulation)	js/sims/, e.g. js/sims/logistic.js (tested by node tools/test-logistic.mjs)
Card 2: the continuous-time logistic model	simulations/population-dynamics/continuous-logistic/ + js/sims/continuous-logistic.js (tested by node tools/test-continuous-logistic.mjs)
Card 3: harvesting with Holling responses	simulations/population-dynamics/harvesting/ + js/sims/harvesting.js (tested by node tools/test-harvesting.mjs)
Card 4: Lotka–Volterra competition	simulations/population-dynamics/lv-competition/ + js/sims/lv-competition.js (tested by node tools/test-lv-competition.mjs)
Card 5: the consumer–resource model	simulations/population-dynamics/consumer-resource/ + js/sims/consumer-resource.js (tested by node tools/test-consumer-resource.mjs)
Card 6: prey–predator models	simulations/population-dynamics/prey-predator/ + js/sims/prey-predator.js (tested by node tools/test-prey-predator.mjs)
Plots in chalk style (axes, lines, legends, log axes)	js/lib/plot.js
ODE solvers: Dormand–Prince, ROS2 for stiff models, 2×2 eigenvalues	js/lib/ode.js (tested by node tools/test-ode.mjs)
Shared page helpers for the simulations: sliders, boxes, runtime checks	js/lib/simkit.js
Checking tools: screenshots, slider sweeps, error pass, page changes, preview	tools/dev/ (see its README)
Elementary Mathematics: title and the list of chapters (the boxes are made by tools/publish/build.py)	elementary-mathematics/index.html
Blog posts and maths chapters: what you write (Google Doc, Markdown, R Markdown, LaTeX, knitted HTML)	content/blog/, content/maths/ — how to write and publish: content/README.md
The pages made from them (don't edit: they are rewritten on every publish)	blogs/<name>/, elementary-mathematics/<name>/
Publishing: files → pages, maths typeset (MathJax), photos resized; the page templates	tools/publish/build.py, tools/publish/templates/; run on GitHub by .github/workflows/publish.yml
Drive → GitHub sync (Google Apps Script)	tools/drive-sync/drive-to-github.gs (tested by node tools/test-drive-sync.cjs)
Styles of the two lists, the posts and chapters, and the strip	css/writing.css
Comments page	comments/index.html
Colours, fonts, sizes, where each section's text sits	css/site.css (tokens at the top)
The scroll / dust / calm-zone / page-change engine	js/engine/engine.js (settings in CFG)
The six home-page scenes	js/scenes/home.js, simulations.js, elementary.js, lab.js, blog.js, feedback.js
Page backgrounds: drifting pure maths (Elementary Mathematics), snow on grass (chapters), mountains over a sea of clouds with an eagle, faint snow and the grass (blog posts)	js/scenes/pure.js, js/scenes/snowfield.js, js/scenes/summit.js
Falling chalk snow (Feedback, Comments, chapters)	js/lib/snowfall.js
Animals (hare, wolf, deer, tiger, leopard, owl, ibex, snow leopard, eye)	js/lib/creatures.js
The explorer (stick figure with glasses and backpack)	js/lib/explorer.js
Chalk equations, chalk lines, blackboard texture	js/lib/chalk.js + js/data/equations.js and js/data/pure.js (both generated)
Fonts (small subsets) and their licences	fonts/ + fonts/LICENSES.txt
Comment storage (Google Sheet)	js/comments.js + tools/comments-google-apps-script.gs
Old site	trash/ (not linked anywhere)

Every file starts with a comment that explains what it does and has a HOW TO EDIT note listing the settings worth changing.

Common edits

• Text and links: edit index.html. Every section is marked with a comment banner, for example <!-- ===== 2 · SIMULATIONS -->.
• Fill a section page: open its index.html and write below the title.
• Turn on comments: follow the steps at the top of tools/comments-google-apps-script.gs. It takes about 10 minutes. Then paste the web-app URL into SHEET_URL in js/comments.js. To remove a comment, delete its row in the sheet.
• Add or change an equation:
  1. Edit ITEMS in tools/make_equations.py.
  2. Run python3 tools/make_equations.py. This needs LaTeX (pdflatex and pdftocairo).
  3. Use the new id in a scene.
• Add or change a drifting note on the Elementary Mathematics page: edit PURE in tools/make_equations.py and run python3 tools/make_equations.py pure. Every entry appears on the page by itself. Ids starting with n_ are theorem names, the rest are formulas.
• Publish a blog post or a maths chapter: write it in Google Docs (or as a .md, .Rmd, .tex or knitted .html file), start it with the four header lines (title:, date:, category:, abstract:), and put it in your Drive folder WildQuant website/Blog or …/Elementary Mathematics, or upload it to content/blog/ or content/maths/ on github.com. It gets its page and its box on the list by itself. All of it: content/README.md.
• The Blogs background and strip: the peaks, routes, glaciers, parks and words are the lists at the top of js/scenes/gearbox.js; the explorer's activities are ACTS in js/lib/strip.js (the wall's height, how concave it is and the lake's length are in WALL).
• The blog posts' background: js/scenes/summit.js (the mountains, the eagle, how faint the snow is). Posts are made from tools/publish/templates/post.html, which loads it.
• Add a simulation:
  1. Copy a simulation folder to a new folder and write the page: simulations/population-dynamics/discrete-logistic/ for a map, or one of cards 3–6 (e.g. ) for differential equations. Those pages also load the ODE solvers (, ) and the shared sliders and boxes (, ).

Publishing (Blogs and Elementary Mathematics)

What you write lives in content/ (from Drive or uploaded on GitHub); every push to master runs .github/workflows/publish.yml, which makes the pages with tools/publish/build.py, commits them, and deploys the site to GitHub Pages (about two minutes). One-time settings: GitHub → Settings → Pages → Source: GitHub Actions; and the Drive sync script (steps at the top of tools/drive-sync/drive-to-github.gs).

To make the pages on your computer: install pandoc 3.9, then pip install -r tools/publish/requirements.txt, npm install --prefix tools/publish, and run python3 tools/publish/build.py (then preview as above).

Adding a page

Every page of the site opens and closes with the same animation: a click on a link pulls the drawings into the link, and the next page opens under a quick flash from the same spot. A new page gets this, and the blackboard, by being built like the others. The easiest way is to copy a page and change it: copy about/index.html for a plain page, or a chapter for a long read. If you build one from scratch, it needs all of these:

1. In <head>: ../css/site.css and the small inline <script> marked "arriving from another page of the site" (copy it unchanged from any page). Then the scripts ../js/lib/core.js, ../js/lib/chalk.js, ../js/engine/engine.js and, last, ../js/site.js, each with defer.
2. At the top of <body>: the two canvases <canvas id="board-tex" aria-hidden="true"></canvas> and <canvas id="board-fx" aria-hidden="true"></canvas>, and a back link <a class="back" href="../" data-collapse data-back="#home"><span aria-hidden="true">←</span> WildQuant</a>. data-back makes it a back link: it returns to where the visitor left the home page, or to the section it names (here #home, the top) if they never were there. Use the section that links to your page.
3. data-collapse on every link to another page of the site, for example <a href="../about/index.html" data-collapse>. Links to other websites, and # links within a page, do without.
4. data-calm on the text blocks, so the drawings fade behind them.
5. A background (optional): add data-scene="…" to <body> and load the scene's script after engine.js and before site.js. pure (faint drifting maths, also needs ../js/data/pure.js first), snowfield (snow on grass, also needs ../js/lib/snowfall.js first) and summit (mountains, an eagle, snow and grass; also needs snowfall.js, explorer.js and snowfield.js first) are made for pages. Without a scene the page shows the plain blackboard.

Paths are relative to the page's folder: ../ from a page one folder deep (like about/), ../../ from two folders deep (like a chapter), ../../../ from three (like a simulation).

Behaviour notes

• Home intro: it plays once per browser session. Scrolling skips it, and so does opening the page further down (a link like /#feedback, or a back link to where the visitor left).
• Reduced motion: visitors with "reduce motion" switched on see one still drawing per section. Nothing animates for them.
• Phones: they get the same scenes with fewer particles, a smaller flock, and layouts arranged for portrait.
• Calm zones: any element with data-calm keeps the drawings behind it faint. Use data-calm="0.6" for a lighter effect. Animals are never faded: scenes draw them after the calm zones (the "top" pass) and size and place them so they stay clear of the text on any screen shape.
• Page changes: any link with data-collapse pulls the drawings into the link in a third of a second (the next page is fetched at the click and opened as the swirl closes), and the next page shows at once under a quick flash from the same spot; its drawings fade in as soon as the board has started. Every page works this way (see "Adding a page"). A page opens at its top, or at the #section the link names; a back link (data-back) opens it where the visitor left it instead. The small script at the top of every page does this. Timing: collapse and navAt in CFG (js/engine/engine.js); the flash is .wq-arrive and the fade-in .wq-ready #board-fx in css/site.css.
• Starting quickly: a page shows its text first and starts the board right after. Only the scenes on screen are made at once; the others are made a moment later while the page is idle (on the home page with its intro, all at once, so that nothing interrupts the intro).