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A comment on Rocket – A Rust game running on WASM. Parent comment

Re:Rocket – A Rust game running on WASM by Game_Ender on Monday December 04, 2017 @08:33AM (#15843619)
The interface between WASM and JS is limited to native types that WASM supports which is just integers [0] (and maybe doubles?). With that limited API you cannot pass full structures around, the best you can do is pass what are essentially pointers to memory around [1].

[0] - https://developer.mozilla.org/en-US/docs/WebAssembly/Underst...

[1] - https://becominghuman.ai/passing-and-returning-webassembly-a...

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Re:Rocket – A Rust game running on WASM by onion2k on Monday December 04, 2017 @10:33AM (#15844573)
You can do something very similar in plain JS using a sharedArrayBuffer and a webworker. A sharedArrayBuffer is a typed array in an area of shared memory that the worker and the main script can both access. It works really well if it fits your use case. I wrote a 'javascript snow' thing that uses it - https://github.com/onion2k/snowfall
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Re:Rocket – A Rust game running on WASM by wofo on Monday December 04, 2017 @08:37AM (#15843646)
Doubles are supported as well through the `f64` type I think. Interestingly, I am passing booleans in my code as well... and it seems to work.
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Re:Rocket – A Rust game running on WASM by landonxjames on Monday December 04, 2017 @09:06AM (#15843861)
I wonder if its converting them to 0's and 1's and sending that to the javascript?
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Re:Rocket – A Rust game running on WASM by wofo on Wednesday December 06, 2017 @05:12AM (#15859942)
Just checked what is going on and that is indeed the case. Rust booleans compile now to the i32 type (though there is no guarantee that will stay like that in the future).
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