egui/emgui_wasm/src/lib.rs

#![deny(warnings)]

extern crate lazy_static;
extern crate serde_json;
extern crate wasm_bindgen;
// extern crate web_sys;

extern crate emgui;

use std::sync::Mutex;

use emgui::{Emgui, Frame, RawInput};

use wasm_bindgen::prelude::*;

mod app;
mod webgl;

// #[wasm_bindgen]
// pub fn show_gui(raw_input_json: &str) -> String {
//     // TODO: faster interface than JSON
//     let raw_input: RawInput = serde_json::from_str(raw_input_json).unwrap();

//     lazy_static::lazy_static! {
//         static ref APP: Mutex<app::App> = Default::default();
//         static ref EMGUI: Mutex<Emgui> = Default::default();
//     }

//     let mut emgui = EMGUI.lock().unwrap();
//     emgui.new_frame(raw_input);

//     use crate::app::GuiSettings;
//     APP.lock().unwrap().show_gui(&mut emgui.layout);

//     let mut style = emgui.style.clone();
//     emgui.layout.foldable("Style", |gui| {
//         style.show_gui(gui);
//     });
//     emgui.style = style;

//     let commands = emgui.paint();
//     serde_json::to_string(&commands).unwrap()
// }

#[wasm_bindgen]
pub fn new_webgl_painter(canvas_id: &str) -> Result<webgl::Painter, JsValue> {
    let emgui_painter = emgui::Painter::new(); // TODO: don't create this twice
    webgl::Painter::new(canvas_id, emgui_painter.texture())
}

struct State {
    app: app::App,
    emgui: Emgui,
    emgui_painter: emgui::Painter,
}

impl State {
    fn new() -> State {
        State {
            app: Default::default(),
            emgui: Emgui::new(),
            emgui_painter: emgui::Painter::new(),
        }
    }

    fn frame(&mut self, raw_input: RawInput) -> Frame {
        self.emgui.new_frame(raw_input);

        use crate::app::GuiSettings;
        self.app.show_gui(&mut self.emgui.layout);

        let mut style = self.emgui.style.clone();
        self.emgui.layout.foldable("Style", |gui| {
            style.show_gui(gui);
        });
        self.emgui.style = style;

        let commands = self.emgui.paint();
        self.emgui_painter.paint(&commands)
    }
}

#[wasm_bindgen]
pub fn paint_webgl(webgl_painter: &webgl::Painter, raw_input_json: &str) -> Result<(), JsValue> {
    // TODO: nicer interface than JSON
    let raw_input: RawInput = serde_json::from_str(raw_input_json).unwrap();

    lazy_static::lazy_static! {
        static ref STATE: Mutex<Option<State>> = Default::default();
    }

    let mut state = STATE.lock().unwrap();
    if state.is_none() {
        *state = Some(State::new());
    }
    let frame = state.as_mut().unwrap().frame(raw_input);
    webgl_painter.paint(&frame)
}