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
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137

use std;

const NUM_RGB_BYTES: usize = 3;

#[derive(Debug)]
pub struct OpcPixel<'a, T: AsRef<[u8]> + 'a> {
    x: T,
    pub phantom: std::marker::PhantomData<&'a [u8]>,
}

impl<'a, T: AsRef<[u8]> + 'a> OpcPixel<'a, T> {
    pub fn new(x: T) -> Self {
        OpcPixel {
            x: x,
            phantom: std::marker::PhantomData,
        }
    }
    pub fn r(&self) -> u8 {
        self.x.as_ref()[0]
    }
    pub fn g(&self) -> u8 {
        self.x.as_ref()[1]
    }
    pub fn b(&self) -> u8 {
        self.x.as_ref()[2]
    }
}

impl<'a, T: AsRef<[u8]> + AsMut<[u8]> + 'a> OpcPixel<'a, T> {
    pub fn set_r(&mut self, v: u8) {
        self.x.as_mut()[0] = v;
    }
    pub fn set_g(&mut self, v: u8) {
        self.x.as_mut()[1] = v;
    }
    pub fn set_b(&mut self, v: u8) {
        self.x.as_mut()[2] = v;
    }
}

impl<'a, T: AsRef<[u8]> + 'a> std::convert::From<&'a OpcPixel<'a, T>> for (u8, u8, u8) {
    fn from(t: &'a OpcPixel<'a, T>) -> (u8, u8, u8) {
        (t.r(), t.g(), t.b())
    }
}

#[derive(Clone,Debug)]
pub struct Pixels {
    pixels: Vec<u8>,
}

impl std::convert::From<Vec<u8>> for Pixels {
    fn from(t: Vec<u8>) -> Pixels {
        let mut t = t;
        let blen: usize = t.len() - (t.len() % NUM_RGB_BYTES);
        t.truncate(blen);
        Pixels { pixels: t }
    }
}

impl std::convert::From<Pixels> for Vec<u8> {
    fn from(t: Pixels) -> Vec<u8> {
        t.pixels
    }
}

impl Pixels {
    pub fn new(n: usize) -> Pixels {
        Pixels { pixels: vec![0;n*NUM_RGB_BYTES] }
    }

    pub fn iter(&self) -> PixelIterator {
        PixelIterator::new(self)
    }

    pub fn iter_mut(&mut self) -> PixelIteratorMut {
        PixelIteratorMut::new(self)
    }
}

pub struct PixelIterator<'a> {
    p: std::slice::Chunks<'a, u8>,
}

impl<'a> PixelIterator<'a> {
    fn new(p: &'a Pixels) -> Self {
        PixelIterator { p: p.pixels.chunks(NUM_RGB_BYTES) }
    }
}

impl<'a> std::iter::Iterator for PixelIterator<'a> {
    type Item = OpcPixel<'a, &'a [u8]>;

    fn next(&mut self) -> Option<Self::Item> {
        self.p.next().map(|x| OpcPixel::new(x))
    }

    fn nth(&mut self, n: usize) -> Option<Self::Item> {
        self.p.nth(n).map(|x| OpcPixel::new(x))
    }

}

impl<'a> ExactSizeIterator for PixelIterator<'a> {
    fn len(&self) -> usize {
        self.p.len()
    }
}

pub struct PixelIteratorMut<'a> {
    p: std::slice::ChunksMut<'a, u8>,
}

impl<'a> PixelIteratorMut<'a> {
    fn new(p: &'a mut Pixels) -> Self {
        PixelIteratorMut { p: p.pixels.chunks_mut(NUM_RGB_BYTES) }
    }
}

impl<'a> std::iter::Iterator for PixelIteratorMut<'a> {
    type Item = OpcPixel<'a, &'a mut [u8]>;

    fn next(&mut self) -> Option<Self::Item> {
        self.p.next().map(|x| OpcPixel::new(x))
    }

    fn nth(&mut self, n: usize) -> Option<Self::Item> {
        self.p.nth(n).map(|x| OpcPixel::new(x))
    }

}

impl<'a> ExactSizeIterator for PixelIteratorMut<'a> {
    fn len(&self) -> usize {
        self.p.len()
    }
}