rusty-wacc-viewer VS watt

While a "host" application (for the WASM runtime used) is required to enable access to graphical output (or user input) it doesn't have to be a browser.

At the (almost) most basic level a chunk of memory can be used as a framebuffer--the host application would read the pixel data which the WASM bytecode wrote and then write it to the host display via OS-level routines.

There are some plans/experiments at making a framebuffer "device" available as part of WASI.

I've written a couple of graphical WASM host applications that aren't browsers (and which don't use memory for pixel data transfer just integer values returned from a function):

The "WebAssembly Calling Card (WACC) Viewer" is implemented via the Godot game engine and an addon that integrates the Wasmtime WASM runtime with the engine: https://wacc.rancidbacon.com

(Also implemented a WACC Viewer in Rust: https://gitlab.com/RancidBacon/rusty-wacc-viewer)

WACC specifies how to transform three integer values (returned from a function in a WASM module) into a coloured triangle in order to render it on screen.

Another "host application" I implemented was a libretro compatible plugin that loads a WASM module and then feeds the module with input from libretro & retrieves framebuffer pixel data (one pixel at a time :D ) via a WASM function call & writes it to the libretro framebuffer for display.

The precompiled binary is not a sandboxed WASM binary. Despite the name "watt" it has nothing to do with https://github.com/dtolnay/watt . You can look at the actual code to see for yourself.

* Related: watt is one approach to pre-compile proc-macro crates using WASM.

In addition to thiserror and anyhow, our resident superhuman Rust-improving Robot, dtolnay, also developed an experiment in distributing precompiled proc macros as WebAssembly named Watt and, though I never bothered to create a Zulip account so I don't know what was said, I'm told there has been discussion around the idea of implementing something in that vein.

I think when we have Cranelift, Mold, and maybe Watt all working together then compile times will basically be a non-issue. It'll be a few years though.

Check out https://github.com/dtolnay/watt - it's a really interesting solution to the problem!

I really like the idea of Watt: https://github.com/dtolnay/watt Run macros in a wasm sandbox so they can't touch anything you don't explicitly allow.

I really wish there was more interest in getting something like Watt upstreamed.