cosmic-mobile

Latest change d22956783f74f68f3d7eff1dd31f885aaf0fbe3e - Checkpoint BúiOS prototype and document clean-worktree workflow by AkurAI Build

use eframe::egui::*;

pub fn active(t: f32) -> bool {
    t < 3.
}
pub fn particle(i: usize, t: f32) -> (f32, f32) {
    let a = i as f32 * 2.399963;
    let k = (t / 2.).clamp(0., 1.);
    let k = k * k * (3. - 2. * k);
    let radius = 110. + (i % 53) as f32 * 3.;
    let spin = a + t.min(2.) * 2.;
    let target = (a.cos() * 125., a.sin() * 55.);
    (
        (1. - k) * spin.cos() * radius + k * target.0,
        (1. - k) * spin.sin() * radius + k * target.1,
    )
}

// Repaint/timed-painter pattern: emilk/egui 0.33.3 dancing_strings.rs (MIT/Apache-2.0).
// ponytail: CPU-projected particles rendered by existing OpenGL; no 3D mesh or new renderer.
pub fn paint(ctx: &Context, t: f32) {
    if !active(t) {
        return;
    }
    ctx.request_repaint();
    let alpha = ((3. - t) / 0.5).clamp(0., 1.);
    let p = ctx.layer_painter(LayerId::new(Order::Tooltip, Id::new("boot")));
    let rect = ctx.content_rect();
    p.rect_filled(
        rect,
        0,
        Color32::from_rgba_unmultiplied(12, 17, 32, (255. * alpha) as u8),
    );
    let center = rect.center();
    for i in 0..240 {
        let (x, y) = particle(i, t);
        let depth = ((i as f32 * 2.399963).sin() + 1.) / 2.;
        p.circle_filled(
            center + vec2(x, y),
            0.8 + depth * 1.7,
            Color32::from_rgba_unmultiplied(110, 190, 255, (alpha * (80. + depth * 150.)) as u8),
        );
    }
    let reveal = ((t - 1.) / 0.8).clamp(0., 1.) * alpha;
    p.text(
        center,
        Align2::CENTER_CENTER,
        "BúiOS",
        FontId::proportional(48.),
        Color32::from_white_alpha((255. * reveal) as u8),
    );
}