egui/example_wasm/src/lib.rs

129 lines
4.1 KiB
Rust

#![deny(warnings)]
extern crate serde_json;
extern crate wasm_bindgen;
extern crate emigui;
extern crate emigui_wasm;
use {
emigui::{
color::srgba,
containers::*,
example_app::ExampleApp,
label,
widgets::{Label, Separator},
Align, Emigui, RawInput, TextStyle, *,
},
emigui_wasm::now_sec,
};
use wasm_bindgen::prelude::*;
#[wasm_bindgen]
pub struct State {
example_app: ExampleApp,
emigui: Emigui,
webgl_painter: emigui_wasm::webgl::Painter,
frame_times: std::collections::VecDeque<f64>,
}
impl State {
fn new(canvas_id: &str, pixels_per_point: f32) -> Result<State, JsValue> {
Ok(State {
example_app: Default::default(),
emigui: Emigui::new(pixels_per_point),
webgl_painter: emigui_wasm::webgl::Painter::new(canvas_id)?,
frame_times: Default::default(),
})
}
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.emigui.begin_frame(raw_input);
let mut region = self.emigui.background_region();
let mut region = region.centered_column(region.available_width().min(480.0));
region.set_align(Align::Min);
region.add(label!("Emigui!").text_style(TextStyle::Heading));
region.add_label("Emigui is an immediate mode GUI written in Rust, compiled to WebAssembly, rendered with WebGL.");
region.add_label(
"Everything you see is rendered as textured triangles. There is no DOM. There are no HTML elements."
);
region.add_label("This is not JavaScript. This is Rust, running at 60 FPS. This is the web page, reinvented with game tech.");
region.add_label("This is also work in progress, and not ready for production... yet :)");
region.horizontal(Align::Min, |region| {
region.add_label("Project home page:");
region.add_hyperlink("https://github.com/emilk/emigui/");
});
region.add(Separator::new());
region.set_align(Align::Min);
region.add_label("WebGl painter info:");
region.indent("webgl region", |region| {
region.add_label(self.webgl_painter.debug_info());
});
let mean_frame_time = if self.frame_times.is_empty() {
0.0
} else {
self.frame_times.iter().sum::<f64>() / (self.frame_times.len() as f64)
};
region.add(
label!(
"Frame time: {:.1} ms (excludes painting)",
1e3 * mean_frame_time
)
.text_style(TextStyle::Monospace),
);
// TODO: Make it even simpler to show a window
Window::new("Examples")
.default_pos(pos2(32.0, 300.0))
.default_size(vec2(300.0, 400.0))
.show(region.ctx(), |region| {
self.example_app.ui(region);
});
Window::new("Emigui settings")
.default_pos(pos2(400.0, 300.0))
.default_size(vec2(400.0, 400.0))
.show(region.ctx(), |region| {
self.emigui.ui(region);
});
let bg_color = srgba(0, 0, 0, 0); // Use background css color.
let (output, batches) = self.emigui.end_frame();
self.frame_times.push_back(now_sec() - everything_start);
while self.frame_times.len() > 30 {
self.frame_times.pop_front();
}
self.webgl_painter.paint_batches(
bg_color,
batches,
self.emigui.texture(),
pixels_per_point,
)?;
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())
}