egui/crates/egui_demo_lib/src/demo/dancing_strings.rs
Emil Ernerfeldt 8ce0e1c520
Avoid deadlocks by using lambdas for context lock (#2625)
ctx.input().key_pressed(Key::A) -> ctx.input(|i| i.key_pressed(Key::A))
2023-01-25 10:24:23 +01:00

67 lines
2.1 KiB
Rust

use egui::{containers::*, *};
#[derive(Default)]
#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
#[cfg_attr(feature = "serde", serde(default))]
pub struct DancingStrings {}
impl super::Demo for DancingStrings {
fn name(&self) -> &'static str {
"♫ Dancing Strings"
}
fn show(&mut self, ctx: &Context, open: &mut bool) {
use super::View as _;
Window::new(self.name())
.open(open)
.default_size(vec2(512.0, 256.0))
.vscroll(false)
.show(ctx, |ui| self.ui(ui));
}
}
impl super::View for DancingStrings {
fn ui(&mut self, ui: &mut Ui) {
let color = if ui.visuals().dark_mode {
Color32::from_additive_luminance(196)
} else {
Color32::from_black_alpha(240)
};
Frame::canvas(ui.style()).show(ui, |ui| {
ui.ctx().request_repaint();
let time = ui.input(|i| i.time);
let desired_size = ui.available_width() * vec2(1.0, 0.35);
let (_id, rect) = ui.allocate_space(desired_size);
let to_screen =
emath::RectTransform::from_to(Rect::from_x_y_ranges(0.0..=1.0, -1.0..=1.0), rect);
let mut shapes = vec![];
for &mode in &[2, 3, 5] {
let mode = mode as f64;
let n = 120;
let speed = 1.5;
let points: Vec<Pos2> = (0..=n)
.map(|i| {
let t = i as f64 / (n as f64);
let amp = (time * speed * mode).sin() / mode;
let y = amp * (t * std::f64::consts::TAU / 2.0 * mode).sin();
to_screen * pos2(t as f32, y as f32)
})
.collect();
let thickness = 10.0 / mode as f32;
shapes.push(epaint::Shape::line(points, Stroke::new(thickness, color)));
}
ui.painter().extend(shapes);
});
ui.vertical_centered(|ui| {
ui.add(crate::egui_github_link_file!());
});
}
}