egui/example_wasm/src/lib.rs

112 lines
3.5 KiB
Rust

#![deny(warnings)]
#![warn(clippy::all)]
use std::sync::Arc;
use {
emigui::{
color::srgba, examples::ExampleApp, label, widgets::Separator, Align, RawInput, TextStyle,
*,
},
emigui_wasm::now_sec,
};
use wasm_bindgen::prelude::*;
#[wasm_bindgen]
pub struct State {
examples: ExampleApp,
ctx: Arc<Context>,
webgl_painter: emigui_wasm::webgl::Painter,
frame_times: emigui::MovementTracker<f32>,
}
impl State {
fn new(canvas_id: &str, pixels_per_point: f32) -> Result<State, JsValue> {
let ctx = Context::new(pixels_per_point);
emigui_wasm::load_memory(&ctx);
Ok(State {
examples: Default::default(),
ctx,
webgl_painter: emigui_wasm::webgl::Painter::new(canvas_id)?,
frame_times: emigui::MovementTracker::new(1000, 1.0),
})
}
fn run(&mut self, raw_input: RawInput) -> Result<Output, JsValue> {
let everything_start = now_sec();
let pixels_per_point = raw_input.pixels_per_point;
self.ctx.begin_frame(raw_input);
let mut ui = self.ctx.fullscreen_ui();
let mut ui = ui.centered_column(ui.available_width().min(480.0));
ui.set_align(Align::Min);
ui.add(label!("Emigui!").text_style(TextStyle::Heading));
ui.add_label("Emigui is an immediate mode GUI written in Rust, compiled to WebAssembly, rendered with WebGL.");
ui.add_label(
"Everything you see is rendered as textured triangles. There is no DOM. There are no HTML elements."
);
ui.add_label("This is not JavaScript. This is Rust, running at 60 FPS. This is the web page, reinvented with game tech.");
ui.add_label("This is also work in progress, and not ready for production... yet :)");
ui.horizontal(|ui| {
ui.add_label("Project home page:");
ui.add_hyperlink("https://github.com/emilk/emigui/");
});
ui.add(Separator::new());
ui.set_align(Align::Min);
ui.add_label("WebGl painter info:");
ui.indent("webgl region id", |ui| {
ui.add_label(self.webgl_painter.debug_info());
});
ui.add(
label!(
"CPU usage: {:.2} ms (excludes painting)",
1e3 * self.frame_times.average().unwrap_or_default()
)
.text_style(TextStyle::Monospace),
);
ui.add(
label!(
"FPS: {:.1}",
1.0 / self.frame_times.mean_time_interval().unwrap_or_default()
)
.text_style(TextStyle::Monospace),
);
self.examples.ui(&self.ctx);
let bg_color = srgba(0, 0, 0, 0); // Use background css color.
let (output, batches) = self.ctx.end_frame();
let now = now_sec();
self.frame_times.add(now, (now - everything_start) as f32);
self.webgl_painter.paint_batches(
bg_color,
batches,
self.ctx.texture(),
pixels_per_point,
)?;
emigui_wasm::save_memory(&self.ctx); // TODO: don't save every frame
Ok(output)
}
}
#[wasm_bindgen]
pub fn new_webgl_gui(canvas_id: &str, pixels_per_point: f32) -> Result<State, JsValue> {
State::new(canvas_id, pixels_per_point)
}
#[wasm_bindgen]
pub fn run_gui(state: &mut State, raw_input_json: &str) -> Result<String, JsValue> {
// TODO: nicer interface than JSON
let raw_input: RawInput = serde_json::from_str(raw_input_json).unwrap();
let output = state.run(raw_input)?;
Ok(serde_json::to_string(&output).unwrap())
}