Returning shader's source instead of path in custom Material

[tesfabpel]

I'm trying to create a custom Material but I can't figure out how to create a shader given its source code (included at compile-time via the include_str! macro) in the fragment_shader() function of the Material trait.
That function expects a return type of ShaderRef that is an enum including the Handle variant but since the function is static (it doesn't take a self parameter) and as such, I can't store the Handle as a field as well...

[tim-blackbird]

Internally, Bevy and other plugins do something like this.

const SHADER_HANDLE: HandleUntyped =
	HandleUntyped::weak_from_u64(Shader::TYPE_UUID, /* insert a large random number here */);

// You can use this helper macro as suggested by komadori below :)
load_internal_asset!(
    app,
    SHADER_HANDLE,
    "shader/path.wgsl",
    Shader::from_wgsl
);

// Which expands to the following code.
let mut shaders = app.world.resource_mut::<Assets<Shader>>();
shaders.set_untracked(SHADER_HANDLE, Shader::from_wgsl(include_str!("shader/path.wgsl")));

And then return this handle from fragment_shader().

[komadori]

@devil-ira is correct, but better still Bevy exports the load_internal_asset macro to encapsulate the boilerplate:

https://docs.rs/bevy/latest/bevy/asset/macro.load_internal_asset.html

You still have to think of a large 64-bit random number yourself though 😋.

[tesfabpel]

Thank you! I'll try this later!

[tesfabpel]

Yes, it works ok! Thank you all again!
I find this way a little bit dirty... You have to use a "random" large random number (instead of having bevy assign one for you). Hopefully in a future version there will be a way to register those assets differently...
For example, a game may want to support loading shaders from Steam Workshop (like I believe GMod does) and this static approach is a bit constraining probably, since I can't create a custom material with parameters (the fragment_shader and the vertex_shader functions are parameter-less static) forbidding me to load arbitrary shader files from disk / memory / whatever...