how can I export or import data in Uint8Array format when using wasm version?

[liushzhql]

When using the WebAssembly (wasm) version, how can I export or import navMesh and TileCache data in Uint8Array format? The code file being used is .packages/recast-navigation-wasm/dist/recast-navigation.wasm-compat.js.

[isaac-mason]

Hi, @recast-navigation/wasm isn't really meant for direct use. It's used internally by the main package (recast-navigation / @recast-navigation/core). There isn't a "wasm" and "non-wasm" version.

You can find instructions for using importNavMesh and exportNavMesh methods in the README: https://github.com/isaac-mason/recast-navigation-js#exporting-and-importing

There's also a storybook you can reference: https://github.com/isaac-mason/recast-navigation-js/blob/main/packages/recast-navigation/.storybook/stories/importing-and-exporting.stories.tsx

If you're interested in how the internal @recast-navigation/wasm package works for whatever reason, you can find autogenerated docs here:

• https://docs.recast-navigation-js.isaacmason.com/classes/index.Wasm.NavMeshImporter.html
• https://docs.recast-navigation-js.isaacmason.com/classes/index.Wasm.NavMeshExporter.html

[liushzhql]

Thank you for your reply. I have read the relevant source code and gained a further understanding of the workflow of this project. However, the way WebAssembly is initialized in the project does not work in my target environment, so I have temporarily given it up. Thank you again anyway.

[isaac-mason]

No worries at all!

However, the way WebAssembly is initialized in the project does not work in my target environment, so I have temporarily given it up.

Could you share more details about this? If there's an improvement that can be made, I'd be keen to learn more 🙂

[liushzhql]

I'm currently facing a new challenge: how to make the package packages/recast-navigation-core compatible with the asmjs runtime? Inside, the reference to the @recast-navigation/wasm package is actually using the file recast-navigation.wasm-compat.js. I've already modified the compilation configuration of @recast-navigation/wasm to generate the file ./dist/recast-navigation.asm.js. However, I'm unable to correctly import it in packages/recast-navigation-core/src/raw-module.ts. Neither importing the existing @recast-navigation/wasm/wasm nor the newly added @recast-navigation/asm works. Below is a snippet of the modified package.json from the @recast-navigation/wasm package:

  "type": "module",
  "main": "./dist/recast-navigation.wasm-compat.js",
  "types": "./dist/recast-navigation.d.ts",
  "exports": {
    ".": {
      "import": "./dist/recast-navigation.wasm-compat.js"
    },
    "./wasm": {
      "import": "./dist/recast-navigation.wasm.js"
    },
    "./wasm-compat": {
      "import": "./dist/recast-navigation.wasm-compat.js"
    },
    "./asm": {
      "import": "./dist/recast-navigation.asm.js"
    }
  },
  "files": [
    "dist/recast-navigation.d.ts",
    "dist/recast-navigation.wasm-compat.js",
    "dist/recast-navigation.wasm.js",
    "dist/recast-navigation.wasm.wasm",
    "dist/recast-navigation.asm.js",
    "README.md",
    "LICENSE"
  ],

[isaac-mason]

There's a related issue for letting users choose their wasm build, I'm not working on it right now though: #164

I'm hoping in future I can support something like this in user-land:

import { init } from 'recast-navigation'
import MyChosenRecastBuild from '@recast-navigation/wasm/wasm-compat'

await init(MyChosenRecastBuild)

Also, I haven't tested what the performance is like with asmjs, but I suspect it will be very bad 🙂 just a warning.

---

Regarding your immediate issue, there's a few things we need to do to fix those entrypoints:

• those entrypoints also need a "types" entry for typescript support
• consuming packages (including e.g. @recast-navigation/core) need to use a tsconfig.json moduleResolution option compatible with entrypoints. Right now the packages use "Node", but would need to use an option like "Bundler"

As a work-around for testing, you could change the main export from ./dist/recast-navigation.wasm-compat.js to ./dist/recast-navigation.asm.js

[liushzhql]

Thank you for your response and reminder. I am considering using asm.js primarily for backward compatibility with platforms that do not support wasm. Therefore, I hope for a mechanism that allows for runtime environment detection and dynamic importing.

I look forward to future updates that will support this. Thank you once again.