altered_perception 0.5.0

`struct HSV/Luma/HSL/etc.` for sharing pixels between crates + other pixel manipulations
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
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117

use crate::HSV;
use num_traits::cast::AsPrimitive;
use num_traits::Bounded;
use rgb::RGB;

impl<N: std::convert::Into<f64> + Copy + 'static> HSV<N> {
    /// Converts an rgb pixel into an hsv pixel
    ///
    /// ```
    /// use altered_perception::HSV;
    /// use rgb::RGB;
    ///
    /// let rgb_pixel = RGB::new(1,2,3);
    /// let hsv_pixel: HSV<f64> = HSV::from_rgb::<u8>(rgb_pixel);
    /// ```
    pub fn from_rgb<T: std::convert::Into<f64> + Bounded>(rgb_pixel: RGB<T>) -> HSV<N>
    where
        f64: AsPrimitive<N>,
    {
        let r_prime: f64 = rgb_pixel.r.into() / T::max_value().into();
        let g_prime: f64 = rgb_pixel.g.into() / T::max_value().into();
        let b_prime: f64 = rgb_pixel.b.into() / T::max_value().into();

        let c_max: f64 = r_prime.max(g_prime.max(b_prime));
        let c_min: f64 = r_prime.min(g_prime.min(b_prime));

        // Account for floating point error (avoids divide by zero error)
        let delta: f64 = if c_max - c_min == 0.0 {
            f64::MIN_POSITIVE
        } else {
            c_max - c_min
        };

        let mut hue: f64 = if delta == 0.0 {
            0.0
        } else if c_max == r_prime {
            60.0 * (((g_prime - b_prime) / delta) % 6.0)
        } else if c_max == g_prime {
            60.0 * (((b_prime - r_prime) / delta) + 2.0)
        } else if c_max == b_prime {
            60.0 * (((r_prime - g_prime) / delta) + 4.0)
        } else {
            0.0
        };

        // Accounts for negative degree wrap around
        if hue < 0.0 {
            hue += 360.0;
        }

        let saturation: f64 = if c_max == 0.0 { 0.0 } else { delta / c_max };

        HSV {
            h: hue.as_(),
            s: saturation.as_(),
            v: c_max.as_(),
        }
    }

    /// Creates a single pixel of type N
    pub fn new(h: N, s: N, v: N) -> HSV<N> {
        HSV { h, s, v }
    }

    /// Converts an hsv pixel to an rbg pixel
    ///
    /// ```
    /// use altered_perception::HSV;
    /// use rgb::RGB;
    ///
    /// let hsv_pixel = HSV::new(90.0, 0.5, 0.3);
    /// let rgb_pixel = HSV::to_rgb::<u8>(hsv_pixel);
    /// ```
    pub fn to_rgb<T: std::marker::Copy + 'static + Bounded + std::convert::Into<f64>>(
        hsv_pixel: HSV<N>,
    ) -> RGB<T>
    where
        f64: AsPrimitive<T>,
    {
        let c: f64 = hsv_pixel.v.into() * hsv_pixel.s.into();
        let x: f64 = c * (1.0 - ((hsv_pixel.h.into() / 60.0) % 2.0 - 1.0).abs());
        let m: f64 = hsv_pixel.v.into() - c;

        let (r_prime, g_prime, b_prime) = match hsv_pixel.h.into() as u32 % 360 {
            0..=59 => (c, x, 0.0),
            60..=119 => (x, c, 0.0),
            120..=179 => (0.0, c, x),
            180..=239 => (0.0, x, c),
            240..=299 => (x, 0.0, c),
            300..=359 => (c, 0.0, x),
            _ => (0.0, 0.0, 0.0),
        };

        // Account for overflow
        let r: f64 = if (r_prime + m) * T::max_value().into() > T::max_value().into() {
            0.0
        } else {
            (r_prime + m) * T::max_value().into()
        };
        let g: f64 = if (g_prime + m) * T::max_value().into() > T::max_value().into() {
            0.0
        } else {
            (g_prime + m) * T::max_value().into()
        };
        let b: f64 = if (b_prime + m) * T::max_value().into() > T::max_value().into() {
            0.0
        } else {
            (b_prime + m) * T::max_value().into()
        };

        RGB {
            r: r.round().as_(),
            g: g.round().as_(),
            b: b.round().as_(),
        }
    }
}