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
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
|
//! Environment interactions.
use std::any::Any;
use std::cell::RefCell;
use std::collections::{hash_map::Entry, HashMap};
use std::fmt::{self, Debug, Formatter};
use std::fs;
use std::io::Cursor;
use std::path::{Path, PathBuf};
use std::rc::Rc;
use image::io::Reader as ImageReader;
use image::{DynamicImage, GenericImageView, ImageFormat};
use crate::font::FontLoader;
/// A reference-counted shared environment.
pub type SharedEnv = Rc<RefCell<Env>>;
/// Encapsulates all environment dependencies (fonts, resources).
#[derive(Debug)]
pub struct Env {
/// Loads fonts from a dynamic font source.
pub fonts: FontLoader,
/// Loads resource from the file system.
pub resources: ResourceLoader,
}
/// Loads resource from the file system.
pub struct ResourceLoader {
paths: HashMap<PathBuf, ResourceId>,
entries: Vec<Box<dyn Any>>,
}
/// A unique identifier for a resource.
#[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
pub struct ResourceId(usize);
impl ResourceLoader {
/// Create a new resource loader.
pub fn new() -> Self {
Self { paths: HashMap::new(), entries: vec![] }
}
/// Load a resource from a path.
pub fn load<R: 'static>(
&mut self,
path: impl AsRef<Path>,
parse: impl FnOnce(Vec<u8>) -> Option<R>,
) -> Option<(ResourceId, &R)> {
let path = path.as_ref();
let id = match self.paths.entry(path.to_owned()) {
Entry::Occupied(entry) => *entry.get(),
Entry::Vacant(entry) => {
let data = fs::read(path).ok()?;
let resource = parse(data)?;
let len = self.entries.len();
self.entries.push(Box::new(resource));
*entry.insert(ResourceId(len))
}
};
Some((id, self.get_loaded(id)))
}
/// Retrieve a previously loaded resource by its id.
///
/// # Panics
/// This panics if no resource with this id was loaded.
#[track_caller]
pub fn get_loaded<R: 'static>(&self, id: ResourceId) -> &R {
self.entries[id.0].downcast_ref().expect("bad resource type")
}
}
impl Debug for ResourceLoader {
fn fmt(&self, f: &mut Formatter) -> fmt::Result {
f.debug_set().entries(self.paths.keys()).finish()
}
}
/// A loaded image resource.
pub struct ImageResource {
/// The original format the image was encoded in.
pub format: ImageFormat,
/// The decoded image.
pub buf: DynamicImage,
}
impl ImageResource {
pub fn parse(data: Vec<u8>) -> Option<Self> {
let reader = ImageReader::new(Cursor::new(data)).with_guessed_format().ok()?;
let format = reader.format()?;
let buf = reader.decode().ok()?;
Some(Self { format, buf })
}
}
impl Debug for ImageResource {
fn fmt(&self, f: &mut Formatter) -> fmt::Result {
let (width, height) = self.buf.dimensions();
f.debug_struct("ImageResource")
.field("format", &self.format)
.field("color", &self.buf.color())
.field("width", &width)
.field("height", &height)
.finish()
}
}
|
