Passing data between two functions called from rust
jice-nospam opened this issue · comments
I'm trying to use dyon as a scripting language for a fantasy console coded in rust.
The console calls a init() function defined in the script, then for each frame a render() function is called.
How can I pass a context from the init function to the render function ? Using current object doesn't work because render is not called directly by init itself but by the rust part.
My idea was to return a context from the init function that the rust engine had to pass as parameter to the render function, but the type is unknown at compile time.
You can use this library https://crates.io/crates/current
As far as I understand, this library brings the dyon concept of current object to rust.
My problem is that I don't have a Rust type for the object created by the dyon script.
Is there a way to get a sort of generic reference to a dyon created object and pass it as parameter to a dyon function ?
Basically, rust calls a init() dyon function that returns an object. This object depends on the script and is not known at compile time. Then rust must call a render() dyon function and pass this object as a parameter.
You can use Variable
on the rust side, even if the type is unknown.
Thank you, this works. However, I get an error if the parameter is mutable :
fn init() -> {} {
println("init")
return {t:0,r:1,g:1,b:1,c:1,s:1}
}
fn update(mut ctx) {
println("update")
ctx.t+=0.01
ctx.c=cos(ctx.t)
ctx.s=sin(ctx.t)
}
fn render(ctx) {
gfx_line(40.0,40.0,40.0+ctx.c*20.0,40.0+ctx.s*20.0,1.0,0.0,0.0)
}
The render function is called and works. The update function though return an error :
Could not find function 'update'
I'm calling it with
let call = Call::new("update").arg(self.var.clone());
error(call.run(&mut self.runtime, &self.module));
self.var being the Variable returned by the init function call.
ok the trick was to Call::new("update(mut)")