rust_musiclight/src/userscript.rs
Thomas Kolb 864add8403 Provide SignalProcessing methods to the Lua script
This is accomplished by providing a wrapped reference to the
SignalProcessing instance of the Rust program as a global Lua variable.
The wrapper class implements mlua::UserData, wraps the relevant
SignalProcessing methods and provides them as Lua methods.

So far, this is implemented for get_energy_in_band() only.
2021-02-21 19:49:16 +01:00

134 lines
3.5 KiB
Rust

// vim: noet
/*
* Module for the Lua scripting interface of Musiclight.
*/
/* Test code for reference
// test the mlua crate
let lua_state = Lua::new();
lua_state.globals().set("get_rust_value", lua_state.create_function(|_, ()| {
Ok(3)
}).unwrap()).unwrap();
let user_script = std::fs::read_to_string("test.lua").unwrap();
lua_state.load(&user_script).exec().unwrap();
let lua_func_test : mlua::Function = lua_state.globals().get("test").unwrap();
println!("{}", lua_func_test.call::<_, u32>(123).unwrap());
*/
use crate::config;
use crate::signal_processing::SignalProcessing;
use mlua::Lua;
use mlua::FromLua;
use mlua::Error;
use std::rc::Rc;
use std::cell::RefCell;
pub struct UserScript
{
lua_state: Lua,
}
impl UserScript
{
pub fn new(sigproc: Rc<RefCell<SignalProcessing>>, user_script_path: &str) -> std::result::Result<UserScript, mlua::Error>
{
let s = UserScript {
lua_state: Lua::new(),
};
// provide some configuration constants to Lua via a table
let config_table = s.lua_state.create_table()?;
config_table.set("sampling_rate", config::SAMP_RATE)?;
config_table.set("block_length", config::BLOCK_LEN)?;
config_table.set("samples_per_update", config::SAMPLES_PER_UPDATE)?;
s.lua_state.globals().set("CONFIG", config_table)?;
// register the signal processing reference as Lua user data
s.lua_state.globals().set("sigproc", SignalProcessingWrapper{
signal_processing: sigproc
})?;
// load the user script and execute it to make variables and functions available
let user_script = std::fs::read_to_string(user_script_path)?;
s.lua_state.load(&user_script).exec()?;
Ok(s)
}
pub fn init(&self) -> std::result::Result<(), mlua::Error>
{
// find the init functions
let lua_init_func: mlua::Function = self.lua_state.globals().get("init")?;
lua_init_func.call( (config::NUM_STRIPS, config::NUM_LEDS_PER_STRIP) )?;
Ok(())
}
pub fn periodic(&self) -> std::result::Result<(), mlua::Error>
{
// find the init functions
let lua_periodic_func: mlua::Function = self.lua_state.globals().get("periodic")?;
// call the script's periodic() function, which (hopefully) returns four Tables with color
// values
let rvals = lua_periodic_func.call::<_, mlua::MultiValue>( () )?;
// check the number of returned values
if rvals.len() != 4 {
return Err(Error::RuntimeError("Wrong number of return values from 'periodic'. Expected 4.".to_string()));
}
// convert the Lua Tables to normal vectors
let mut colorlists = Vec::<Vec<f32>>::new();
for rval in rvals {
let table = mlua::Table::from_lua(rval, &self.lua_state)?;
let v = table.sequence_values()
.map(|x| x.unwrap())
.collect::<Vec<f32>>();
// check the length of the color array
if v.len() != config::NUM_LEDS_TOTAL {
return Err(Error::RuntimeError("Number of color values returned from 'periodic' must match number of LEDs given in 'init'.".to_string()));
}
colorlists.push(v);
}
println!("{:?}", colorlists[0][0]);
Ok(())
}
}
/*
* Wrap a SignalProcessing instance and provide a Lua interface for some of its methods.
*/
struct SignalProcessingWrapper
{
signal_processing: Rc<RefCell<SignalProcessing>>,
}
impl mlua::UserData for SignalProcessingWrapper
{
fn add_methods<'lua, M: mlua::UserDataMethods<'lua, Self>>(methods: &mut M)
{
methods.add_method("get_energy_in_band", |_, this, (start_freq, end_freq): (f32, f32)| {
Ok(this.signal_processing.borrow().get_energy_in_band(start_freq, end_freq))
});
}
}