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rajsite avatar image
rajsite asked geoffda edited

Technical details about WebAssembly system implementation

Following the Flight Simulator SDK documentation link from @WasmWeekly, I'm finding the WebAssembly approach for creating Flight Simulator plugins very interesting! I've been interested in using WebAssembly as a plugin mechanism for software we develop. The benefits of API control / stability, good performance, cross-platform compatibility, and robustness when running 3rd-party code in-process is all fascinating.

I was wondering if there is any technical share out about how the system was implemented in Flight Simulator with pros, cons, lessons learned, future direction, etc. It seems like a pattern that could potentially be useful in a wide-range of software applications and I'm curious to hear how problems like debugging from Visual Studio were solved and what WASM runtime is used, etc.

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rajsite avatar image rajsite commented ·

Just wanted to check-in again and see if anyone knows if there was any technical share out of how WASM was integrated into Microsoft Flight Simulator or if there is a better venue to ask. I would appreciate any help! :)

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geoffda avatar image
geoffda answered geoffda edited

Microsoft Flight Simulator gets their WASM support from inNative. The SDK is freely available here: The inNative approach used by MSFS is to compile WASM into native code and build it into a dynamic link library prior to execution. If you are intending to add WASM support to your own software, using inNative would be a very simple way of doing it as all of the tools and integration APIs are provided. Alternatively, if you don't want to ship open source, don't like the license, or need to JIT compile, you could roll your own development tools. The WebAssembly org provides complete technical documentation of the WebAssembly specifications, so you could implement your own compiler, runtime, etc.

From the perspective of developing add-ons for Microsoft Flight Simulator, I will say that WASM totally sucks. The only real benefit it offers for MSFS development is cross-platform support, but so far that has been a bit of a bust. The trade-off to enable cross-platform is extremely limited API access from within the WASM runtime. Combine lack of functionality with poor debugging tools and the end result is an environment where the set of the few things that can be done is vastly dominated by the set of most things which cannot be done.

Outside of Microsoft Flight Simulator, integrating WebAssembly could be a good choice; it all depends on what you are trying to allow plug-in developers to accomplish and how much functionality you are willing to expose to the runtime.

You might also be interested in the "WASM Deep Dive" document that I created which can be found here: WASM Deep Dive - SDK Discussion / Tutorials - Microsoft Flight Simulator Forums

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