Web, Commodore, Windows version, Linux standalone, Windows Screensaver complete.

README.md

@@ -157,6 +157,99 @@ To install on Windows: right-click `vectorgons.scr` → **Install** (or copy it
 `C:\Windows\System32` and choose it under *Settings → Personalization → Lock
 screen → Screen saver*). Like the `.exe`, it needs only Windows system DLLs.
 
+## Browser (WebAssembly)
+
+The same source compiles to WebAssembly with [Emscripten](https://emscripten.org),
+which maps the GLFW3 windowing and the legacy/immediate-mode OpenGL onto WebGL
+(`-sLEGACY_GL_EMULATION`). The retained-mode VBO geometry, the FBO bloom, and the
+frustum culling all run unchanged; the browser-specific bits (GLU helpers, the
+`requestAnimationFrame` main loop, and the WebGL-incompatible `double`/`glReadBuffer`
+calls) are guarded behind `#ifdef __EMSCRIPTEN__`.
+
+```sh
+source /path/to/emsdk/emsdk_env.sh   # put emcc on PATH
+make web                             # -> web/vectorgons.js + web/vectorgons.wasm
+```
+
+Serve the `web/` directory over HTTP (WebAssembly will **not** load from a
+`file://` URL) and open `index.html`:
+
+```sh
+cd web && python3 -m http.server 8000   # then visit http://localhost:8000/
+```
+
+`web/index.html` is a ready-made page. To embed in your own page, drop a focusable
+canvas with `id="canvas"`, point Emscripten's `Module` at it, and load the script:
+
+```html
+<canvas id="canvas" width="1100" height="760" tabindex="0"></canvas>
+<script>
+  var Module = { canvas: document.getElementById('canvas') };
+</script>
+<script src="vectorgons.js"></script>
+```
+
+Serve `vectorgons.js`, `vectorgons.wasm`, and `vectorgons-boot.js` from the same
+directory. Click the canvas to give it keyboard focus; all the usual controls
+then work, and `F` requests browser fullscreen. (Settings are not persisted in
+the browser.)
+
+### Content-Security-Policy
+
+WebAssembly needs a couple of CSP allowances. If your server sends a strict CSP
+(symptom: the canvas appears but nothing runs, and the console shows
+`both async and sync fetching of the wasm failed`), the page's `script-src` must
+include **`'wasm-unsafe-eval'`** (required to instantiate any WASM — there is no
+nonce/hash alternative) and **`connect-src`** must allow fetching the `.wasm`
+(e.g. `'self'`). Loading the `Module` config from `vectorgons-boot.js` (rather
+than an inline `<script>`) means `'unsafe-inline'` is *not* required. A working
+policy for the Vectorgons path:
+
+```
+script-src 'self' 'wasm-unsafe-eval'; connect-src 'self';
+```
+
+## Commodore 64 (`c64/`)
+
+A bonus port for the original 1982 hardware lives in [`c64/`](c64/). The 1 MHz
+6510 has no floating-point unit and a 1-bit, 320×200 hi-res bitmap, so this is a
+ground-up reimplementation rather than the OpenGL engine recompiled — but it
+keeps the heart of Vectorgons: **tumbling wireframe polytopes**, cycling through
+a small shape library (cube, octahedron, tetrahedron, stellated star, pyramid,
+and a 4-D tesseract shadow) in classic monochrome vector-graphics style.
+
+Per the brief, the glass / metal / mirror objects are dropped — there is no
+shading on a 1-bit bitmap. The compromises that make it fit a C64:
+
+- **Integer fixed-point everywhere** — a 256-entry signed sine table (scale 128)
+  drives the 3-D rotation; points are perspective-projected with integer divide.
+- **One object at a time**, drawn with a Bresenham line routine straight into the
+  VIC-II hi-res bitmap; each frame erases the previous edges and draws the new
+  ones (no full-screen clear) so it stays flicker-free without double buffering.
+- Precomputed bitmap row/column/bit-mask address tables for fast plotting.
+- A custom cc65 linker config keeps program code below `$2000`, reserves
+  `$2000–$3FFF` for the bitmap, and puts BSS/heap/stack above it.
+
+Build it with [cc65](https://cc65.github.io/) and pack it onto a disk image with
+VICE's `c1541`:
+
+```sh
+cd c64
+make d64          # -> vectorgons.prg and vectorgons.d64
+make run          # build + launch in the VICE x64sc emulator
+```
+
+If `cl65`/`c1541` aren't on your `PATH`, point the Makefile at them, e.g.
+`make d64 CL65=/path/to/cl65 CC65_HOME=/path/to/share/cc65`. On real hardware (or
+an emulator) load it the usual way and it autostarts:
+
+```
+LOAD"VECTORGONS",8,1
+RUN
+```
+
+Press any key to return to BASIC.
+
 ## Settings persistence
 
 Your settings are saved automatically on exit to `~/.vectorgons` (a plain