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use crate::bitmap::MapPoint;
// dither intensities (bayers)
// 0: none
// 1: (0, 0)
// 2: (2, 2)
// 3: (0, 2)
// 4: (2, 0)
// 5: (1, 1)
// 6: (3, 3)
// 7: (1, 3)
// 8: (3, 1)
// 9: (0, 1)
// 10: (0, 3)
// 11: (2, 3)
// 12: (2, 1)
// 13: (1, 0)
// 14: (3, 2)
// 15: (1, 2)
// 16: (3, 0)
pub fn bayer(level: u8, pt: MapPoint) -> bool {
if level == 0 {
false
} else {
let MapPoint { x, y } = pt;
let r = (x % 4, y % 4);
match level {
1 => r == (0, 0) || bayer(0, pt),
2 => r == (2, 2) || bayer(1, pt),
3 => r == (0, 2) || bayer(2, pt),
4 => r == (2, 0) || bayer(3, pt),
5 => r == (1, 1) || bayer(4, pt),
6 => r == (3, 3) || bayer(5, pt),
7 => r == (1, 3) || bayer(6, pt),
8 => r == (3, 1) || bayer(7, pt),
9 => r == (0, 1) || bayer(8, pt),
10 => r == (0, 3) || bayer(9, pt),
11 => r == (2, 3) || bayer(10, pt),
12 => r == (2, 1) || bayer(11, pt),
13 => r == (1, 0) || bayer(12, pt),
14 => r == (3, 2) || bayer(13, pt),
15 => r == (1, 2) || bayer(14, pt),
16 => r == (3, 0) || bayer(15, pt),
_ => panic!("Invalid dither level!"),
}
}
}
// dither intensities (rylander)
// 0: none
// 1: (1, 3)
// 2: (3, 1)
// 3: (3, 3)
// 4: (1, 1)
// 5: (1, 2)
// 6: (3, 0)
// 7: (3, 2)
// 8: (1, 0)
// 9: (0, 3)
// 10: (2, 1)
// 11: (2, 3)
// 12: (0, 1)
// 13: (0, 2)
// 14: (2, 0)
// 15: (2, 2)
// 16: (0, 0)
pub fn rylander(level: u8, pt: MapPoint) -> bool {
if level == 0 {
false
} else {
let MapPoint { x, y } = pt;
let r = (x % 4, y % 4);
match level {
1 => r == (1, 3) || rylander(0, pt),
2 => r == (3, 1) || rylander(1, pt),
3 => r == (3, 3) || rylander(2, pt),
4 => r == (1, 1) || rylander(3, pt),
5 => r == (1, 2) || rylander(4, pt),
6 => r == (3, 0) || rylander(5, pt),
7 => r == (3, 2) || rylander(6, pt),
8 => r == (1, 0) || rylander(7, pt),
9 => r == (0, 3) || rylander(8, pt),
10 => r == (2, 1) || rylander(9, pt),
11 => r == (2, 3) || rylander(10, pt),
12 => r == (0, 1) || rylander(11, pt),
13 => r == (0, 2) || rylander(12, pt),
14 => r == (2, 0) || rylander(13, pt),
15 => r == (2, 2) || rylander(14, pt),
16 => r == (0, 0) || rylander(15, pt),
_ => panic!("Invalid dither level!"),
}
}
}
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