For the record - I can't imagine any tangible value in writing a graphics engine (and form library) for an environment that was literally designed as a graphics engine for forms. But, that disclaimer aside, I've considered WASM for graphics for a game engine and I have had some trial success with allocating a shared array buffer, writing to it in WASM and reading from it at a js-friendly rate of 30-60 fps (whatever requestAnimationFrame is serving). The idea being that you treat the shared array buffer as your "screen" and write to it from the WASM as if it were an image buffer, while on the JS side you read it as an image buffer onto the canvas. Gives you a nice, finite, bandwidth and an easy to scale maximum for how much data you can pass through, and neither JS nor WASM ever has to pass any time-critical data.

Of course, this setup leaves a very thin JS client - it's essentially just rendering the same image over and over. So if you've already got everything done in JS, it would mean porting all of your functional code over to something that can compile into WASM. Not a huge lift, but not fun either.

And then, on the other hand, if it's just rendering you're seeing as a bottleneck, JS works pretty well with webGL and webGPU for simple form rendering. A little loop unrolling might be a lot easier than porting the rest of the app.

Anyway, best of luck on it!

have you done any benchmarks to compare wasm performance with js? i have been doing some benchmark test cases after a large refactor of my game engine written in typescript that is built entirely on top of shared buffer arrays (using ECS pattern or so it’s called i guess). i’m done benching for a while now and am ok with results but i have also compared my handcrafted quadtree sort/query algorithm with off the shelf rust implementation that matched the test requirements and saw only 30% gain and figured anything lower than that would not be worth the effort assuming rust compiled to wasm is same or slower and never bothered to test compiled wasm because i could not figure out how to share my buffer arrays with the rust code using wasm bindgen fast enough to bother spending more time on more benching lol