Looking forward to trying Compose Web/Canvas on the Wasm target (Kotlin 1.8.20-Beta). Is there a publicly accessible repo with ready-to-use libraries? Currently I'm getting:

No matching variant of org.jetbrains.compose.web:web-core:1.4.0-alpha01-dev958 was found. The consumer was configured to find a usage of 'kotlin-runtime' of a library, preferably optimized for non-jvm, as well as attribute 'org.jetbrains.kotlin.platform.type' with value 'wasm'

More details here: https://kotlinlang.slack.com/archives/C01F2HV7868/p1677883524077679?thread_ts=1660083398.571449&cid=C01F2HV7868

The only public working example of a Wasm + Compose configuration that I'm aware of, can be found here: https://github.com/JetBrains/compose-jb/tree/wasm-jb/experimental/examples/falling-balls-mpp

Thank you for the hint! Seems like it depends on project-internal artifacts, but i’ll have a closer look.

Yeah; It has changed since a few weeks ago. I had a stripped down version that just had the Wasm target in it, and that's stopped working because the

1.8.20

based artifacts have been removed.

I‘ll try to get back to that later. Could be tomorrow for you, though. 🙃 I’ll keep you posted. 👍

image.png

Finally got that counting grid to run on full Wasm (with a custom compiled compose-jb on the wasm-main branch). In an example scenario (25x25 grid, highlighting recompositions), the frame rate improved from 40 FPS (K/Js) to about 60 FPS (K/Wasm). 50% faster. 🎉 For reference: JVM desktop speed on that (slow) machine is 112 FPS. The picture changed when turning on animations (vertically sliding digits): K/Js at 14 FPS, K/Wasm at just 4 FPS – 70% slower. 🤔 Other takeaways: Configuration is hard, as we suspected. Libraries lack Wasm targets (I had to stop using kotlinx.datetime). But

BrowserViewportWindow

still works with K/Js and K/Wasm! So stuff is moving fast and in the right direction. Once I'll see text fields starting to work properly on canvas, things are going to get serious. 🚀😃

@Oliver.O I cannot find the Kotlin/Wasm target on your GitHub project. I guess you haven’t published it there?

No, this is not published currently, as it is hacked into the

compose-jb

project, which is not that quick&easy to set up. I could of course publish a fork, but that would be out of date pretty quickly, and people would have to specifically look up the

wasm-main

branch, so I guess usability is too bad right now to do that. Maybe a better option would be to just be patient and wait for a compose library including the

wasm

target to appear, and then update the counting grid project to use it. I'll reconsider if there is demand.

yes, no worries I am sure Compose for Wasm will appear pretty soon

Amazing!

Correction: The results above were in part comparing apples and oranges (different Compose versions). Also, the initial Js FPS rate reported above was a bit too low (my machine always has its own agenda). These are more accurate numbers (25x25 grid, highlighting recompositions, animations turned off): • Compose 1.4.0-alpha01-dev958 Js: 43 FPS • Compose 2023-02-24/wasm-main Js: 47 FPS (+9% vs. 1.4.0-alpha01-dev958 Js) • Compose 2023-02-24/wasm-main Wasm: 60 FPS (+28% vs. 2023-02-24/wasm-main Js, +40% vs. 1.4.0-alpha01-dev958 Js) With animations (vertically sliding digits) turned on: • Compose 1.4.0-alpha01-dev958 Js: 14 FPS • Compose 2023-02-24/wasm-main Js: 14 FPS • Compose 2023-02-24/wasm-main Wasm: 4 FPS (-70% vs. Js)

@Oliver.O yes, please

Cool, will do.