figcraft/packaging/web/README.md

5.6 KiB

Hosting FigCraft for the web

figcraft-web-<version>.zip (from the GitHub release, or packaging/web/package.sh) holds a static site in figcraft-web-<version>/:

File What it is
index.html The page. It loads everything through relative URLs.
figcraft-web-<hash>.js wasm-bindgen glue (generated, ES module)
figcraft-web-<hash>_bg.wasm The app: about 18 MiB raw, 7 MiB with gzip, 4.5 MiB with Brotli (see Sizes)
_headers, .htaccess Sample header rules for Netlify/Cloudflare Pages and Apache

There is no server-side code and no hand-written JavaScript: the glue is generated by wasm-bindgen from the Rust sources (apps/figcraft-web). Upload the folder's contents anywhere that serves static files.

The editor runs entirely on the visitor's device. The web build starts with one new document; there is no desktop TCP control server, and native file dialogs aren't wired up yet. A browser with WebGPU or WebGL2 is required.

Live sessions

The web build can join a live session hosted by the desktop app (File ▸ Join live session…, then paste the invite link); it can't host one. Desktop-hosted sessions use plain ws://, which browsers block from a page served over https:// except to the same computer. To join sessions on other machines, serve the site over http:// on a trusted network (or use the desktop app); wss:// comes with the standalone server.

Sizes

Measured on the 0.1.0 build (trunk build --release; gzip -9, Brotli quality 11):

File Raw gzip Brotli
figcraft-web-<hash>_bg.wasm 18,534,563 bytes (17.7 MiB) 7,023,460 (6.7 MiB) 4,642,764 (4.4 MiB)
figcraft-web-<hash>.js about 148 KB about 22 KB

Per-file upload limits: Cloudflare Pages and Workers static assets reject any file over 25 MiB (26,214,400 bytes). packaging/web/package.sh fails the build if the wasm ever grows past 24 MiB, so a release can't ship a file a common host refuses.

Any path works

All URLs in index.html are relative (public_url = "./" in apps/figcraft-web/Trunk.toml), so the site works at a domain root (https://example.com/), under a prefix (https://example.com/tools/figcraft/) and from a CDN bucket. The asset names carry a content hash, so they can be cached forever. Only index.html needs revalidation.

Required server settings

  • MIME type: serve .wasm as application/wasm. Browsers refuse to stream-compile it under any other type, and the app then loads slowly or not at all. Serve .js as text/javascript. Most hosts already do both. For nginx, check that mime.types has application/wasm wasm;.
  • Compression: turn on gzip or Brotli for .wasm, .js and .html. That takes the download from about 18 MiB to about 7 MiB (gzip) or 4.5 MiB (Brotli). You can also precompress (brotli -k *.wasm) and let the server send Content-Encoding: br.
  • Caching: Cache-Control: public, max-age=31536000, immutable on the hashed .wasm and .js files, and no-cache on index.html.
  • HTTPS: WebGPU (and the clipboard) only work in a secure context, which means https:// or http://localhost. Over plain HTTP elsewhere, the app falls back to WebGL2.
  • No special isolation headers: FigCraft doesn't use SharedArrayBuffer, so it doesn't need Cross-Origin-Opener-Policy or Cross-Origin-Embedder-Policy. If your site already sends COEP require-corp, also send Cross-Origin-Resource-Policy: same-origin (or cross-origin when the files live on a CDN) on the app's files.

nginx example:

location /figcraft/ {
    types { application/wasm wasm; text/javascript js; text/html html; }
    gzip on;
    gzip_types application/wasm text/javascript text/html;
    location ~* \.(wasm|js)$ { add_header Cache-Control "public, max-age=31536000, immutable"; }
    location ~* index\.html$ { add_header Cache-Control "no-cache"; }
}

Local test: python3 -m http.server 8767 inside the folder, then open http://localhost:8767/.

Embedding in a page (iframe)

<iframe
  src="https://example.com/figcraft/"
  title="FigCraft interface design tool"
  style="width: 100%; height: 720px; border: 0;"
  allow="fullscreen; clipboard-read; clipboard-write"
  allowfullscreen>
</iframe>
  • The app fills the iframe and follows its size, so size the iframe and not the app.
  • Keyboard shortcuts go to the iframe after the user clicks into it, as with any embedded app.
  • Sandboxed iframes need at least sandbox="allow-scripts allow-same-origin allow-popups" (allow-popups lets Help links open in a new tab).
  • Don't send X-Frame-Options: DENY or a frame-ancestors CSP that excludes the embedding page.

Renderer selection and fallback flags

FigCraft renders with wgpu. It uses WebGPU when the browser has it and falls back to WebGL2 on its own. A URL query flag overrides this, and it works on the iframe src too:

Flag Effect
(none) WebGPU if available, otherwise WebGL2
?webgl Force the WebGL2 backend (useful when a WebGPU driver misbehaves, and in headless browsers)

For example: <iframe src="https://example.com/figcraft/?webgl" ...>.

A browser with neither WebGPU nor WebGL2 gets a message in place of the app.

Smoke test (headless Chrome)

Headless Chrome exposes navigator.gpu but its adapter request returns nothing, so force WebGL2 on SwiftShader:

"/Applications/Google Chrome.app/Contents/MacOS/Google Chrome" --headless=new \
  --use-angle=swiftshader --enable-unsafe-swiftshader --window-size=1440,900 \
  --timeout=30000 --screenshot=figcraft-web.png "http://127.0.0.1:8767/?webgl"