WebAssembly

[a-b-street]

WebAssembly

[dabreegster]

Initial proof of concept. ;) It needs a fair bit of work, but I don't see any actual blockers.

[dabreegster]

Currently waiting on RazrFalcon/resvg#229

[dabreegster]

http://abstreet.s3-website.us-east-2.amazonaws.com/

I'm declaring victory. Many things are broken compared to the native version (saving your edits, partially transparent colors), but enough works to try it out! If you find other issues with web specifically, please file more bugs. Thanks!

[dabreegster]

Starting experiments with webgl at https://github.com/dabreegster/rust_wasm_gui_test

[dabreegster]

This is actually getting quite close: https://github.com/dabreegster/abstreet/tree/wasm

• I got almost everything working with glow on native
• glow on webgl isn't drawing yet, probably some simple bug
• need to deal with non-wasm-friendly stuff from a few places -- notably usvg's harfbuzz dependency, reading/writing files, and uses of Instant

As always, I'd love help with this!

[dabreegster]

Do you want me to pursue it @dabreegster?

I have no understanding of this stuff and want to remedy that, so I'll take a crack at it, if that's OK

@alvinhochun, we can pin to particular git commits of winit, so don't let us block any stdweb cleanup. Thanks for checking in!

[dabreegster]

Yes please. This is on my radar, but I don't have any time to work on it soon.

Dependencies right now are glium, glutin, winit. winit got web support recently. The OpenGL usage is contained in the ezgui crate and doesn't use anything fancier than scissor test and texture arrays.

[dabreegster]

Info on the winit support: https://users.rust-lang.org/t/winit-0-20-and-web-support/36155

[Immortalin]

Seems quite laggy?

[dabreegster]

Oh yeah, definitely. I haven't tried in release mode yet, but I bet that'll help. Lots of other bugs to work through before this is anywhere near ready. Probably the hardest piece will be getting some variation of text rendering through usvg without a dependency on harfbuzz.

[alvinhochun]

Hi, I want to let you know that winit is considering deprecating the stdweb backend (rust-windowing/winit#1662). As it appears that A/B street is using winit with stdweb and it doesn't look like you have any plans to move to web-sys, may I ask for your opinion on this?

[dabreegster]

I originally chose stdweb over web-sys many months ago, because it wasn't clear which one was used more, and following the stdweb example seemed slightly easier at the time. I don't think there are any blockers for us switching to web-sys, and we want to use the better maintained option. @michaelkirk did some deep dives into the two recently to fix some bugs and has better context. Should we just migrate to web-sys now?

[michaelkirk]

Yep, I think migrating to web-sys makes sense.

AFAIK the most substantial piece of work will be writing the boilerplate to replace cargo web, which is stdweb only IIRC. I don't think it'll be difficult, just hasn't been a priority.

Do you want me to pursue it @dabreegster?

[michaelkirk]

Be my guest!