1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
|
use crate::{canvas::Frame, triangle};
use iced_native::Size;
use std::cell::RefCell;
use std::sync::Arc;
pub trait Layer: std::fmt::Debug {
fn draw(&self, bounds: Size) -> Arc<triangle::Mesh2D>;
}
use std::marker::PhantomData;
#[derive(Debug)]
pub struct Cached<T: Drawable> {
input: PhantomData<T>,
cache: RefCell<Cache>,
}
#[derive(Debug)]
enum Cache {
Empty,
Filled {
mesh: Arc<triangle::Mesh2D>,
bounds: Size,
},
}
impl<T> Cached<T>
where
T: Drawable + std::fmt::Debug,
{
pub fn new() -> Self {
Cached {
input: PhantomData,
cache: RefCell::new(Cache::Empty),
}
}
pub fn clear(&mut self) {
*self.cache.borrow_mut() = Cache::Empty;
}
pub fn with<'a>(&'a self, input: &'a T) -> impl Layer + 'a {
Bind {
layer: self,
input: input,
}
}
}
#[derive(Debug)]
struct Bind<'a, T: Drawable> {
layer: &'a Cached<T>,
input: &'a T,
}
impl<'a, T> Layer for Bind<'a, T>
where
T: Drawable + std::fmt::Debug,
{
fn draw(&self, current_bounds: Size) -> Arc<triangle::Mesh2D> {
use std::ops::Deref;
if let Cache::Filled { mesh, bounds } =
self.layer.cache.borrow().deref()
{
if *bounds == current_bounds {
return mesh.clone();
}
}
let mut frame = Frame::new(current_bounds.width, current_bounds.height);
self.input.draw(&mut frame);
let mesh = Arc::new(frame.into_mesh());
*self.layer.cache.borrow_mut() = Cache::Filled {
mesh: mesh.clone(),
bounds: current_bounds,
};
mesh
}
}
pub trait Drawable {
fn draw(&self, frame: &mut Frame);
}
|
