// Copied from OxygenHub crates/backdrop/src/scene.rs (6dc080f6) by
// scripts/sync-backdrop.sh: change it there, never here.
//! A backdrop's scene (docs/backgrounds.md §2): what it draws and how it
//! moves. The engine (lib.rs) drives any of them the same way.

use crate::backdrop::sky::{Colours, Kind};

pub trait Scene {
    /// The view is now `w` by `h` CSS pixels, the page's content column
    /// between `avoid`'s left and right.
    fn resize(&mut self, w: f32, h: f32, avoid: Option<(f32, f32)>);
    /// The cursor moved to `(x, y)`, or left the page.
    fn point(&mut self, at: Option<(f32, f32)>);
    /// Move on by `dt` seconds.
    fn step(&mut self, dt: f32);
    /// The marks, 8 floats each (sky::Sky::instances).
    fn instances(&self, c: &Colours, out: &mut Vec<f32>);
    /// The links, 12 floats each (sky::Sky::links).
    fn links(&self, c: &Colours, out: &mut Vec<f32>);
    /// The name a resting cursor shows, and where.
    fn label(&self) -> Option<(&str, f32, f32)>;
    /// New activity in repository `repo` (§5, "Live"); only the sky shows it.
    fn arrive(&mut self, _repo: &str, _kind: Kind, _n: u32) {}
    /// Whether a frame would show anything new besides the drift, which
    /// the engine stops drawing a while after the last input (§6).
    fn busy(&self) -> bool;
    fn still(&self) -> bool;
    fn size(&self) -> (f32, f32);
}

impl Scene for crate::backdrop::sky::Sky {
    fn resize(&mut self, w: f32, h: f32, avoid: Option<(f32, f32)>) {
        crate::backdrop::sky::Sky::resize(self, w, h, avoid)
    }
    fn point(&mut self, at: Option<(f32, f32)>) {
        crate::backdrop::sky::Sky::point(self, at)
    }
    fn step(&mut self, dt: f32) {
        crate::backdrop::sky::Sky::step(self, dt)
    }
    fn instances(&self, c: &Colours, out: &mut Vec<f32>) {
        crate::backdrop::sky::Sky::instances(self, c, out)
    }
    fn links(&self, c: &Colours, out: &mut Vec<f32>) {
        crate::backdrop::sky::Sky::links(self, c, out)
    }
    fn label(&self) -> Option<(&str, f32, f32)> {
        crate::backdrop::sky::Sky::label(self)
    }
    fn arrive(&mut self, repo: &str, kind: Kind, n: u32) {
        crate::backdrop::sky::Sky::arrive(self, repo, kind, n)
    }
    fn busy(&self) -> bool {
        crate::backdrop::sky::Sky::busy(self)
    }
    fn still(&self) -> bool {
        self.still
    }
    fn size(&self) -> (f32, f32) {
        (self.w, self.h)
    }
}