picto 0.4.4

Image handling library.
Documentation 
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

//            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
//                    Version 2, December 2004
//
// Copyleft (ↄ) meh. <meh@schizofreni.co> | http://meh.schizofreni.co
//
// Everyone is permitted to copy and distribute verbatim or modified
// copies of this license document, and changing it is allowed as long
// as the name is changed.
//
//            DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
//   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
//
//  0. You just DO WHAT THE FUCK YOU WANT TO.

use crate::region::Region;

/// Iterator over X and Y coordinates within an `Region`.
#[derive(Eq, PartialEq, Debug)]
pub struct Coordinates {
	x: u32,
	y: u32,

	region: Region,
}

impl Coordinates {
	/// Create a new `Iterator` for the given `Region`.
	#[inline]
	pub fn new(region: Region) -> Self {
		Coordinates { x: 0, y: 0, region }
	}

	/// The `Region` being iterated over.
	#[inline]
	pub fn region(&self) -> Region {
		self.region
	}
}

impl Iterator for Coordinates {
	type Item = (u32, u32);

	#[inline]
	fn next(&mut self) -> Option<Self::Item> {
		if self.x >= self.region.width {
			self.x = 0;
			self.y += 1;
		}

		if self.y >= self.region.height {
			return None;
		}

		self.x += 1;

		Some((self.x - 1 + self.region.x, self.y + self.region.y))
	}

	#[inline]
	fn size_hint(&self) -> (usize, Option<usize>) {
		(self.len(), Some(self.len()))
	}
}

impl ExactSizeIterator for Coordinates {
	#[inline]
	fn len(&self) -> usize {
		let length = self.region.width * self.region.height;
		let remaining = length - (self.y * self.region.width + self.x);

		remaining as usize
	}
}

#[cfg(test)]
mod test {
	use super::*;
	use crate::region::Region;

	#[test]
	fn size_hint() {
		let mut coord = Coordinates::new(Region::from(0, 0, 2, 2));

		assert_eq!(4, coord.size_hint().0);
		coord.next().unwrap();
		assert_eq!(3, coord.size_hint().0);
		coord.next().unwrap();
		assert_eq!(2, coord.size_hint().0);
		coord.next().unwrap();
		assert_eq!(1, coord.size_hint().0);
		coord.next().unwrap();
		assert_eq!(0, coord.size_hint().0);
	}
}