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

use coord_2d::*;
use grid_2d::coord_system::{CoordSystem, XThenY, XThenYIter};
use grid_2d::*;
use orientation::Orientation;
use std::hash::{Hash, Hasher};

#[derive(Clone)]
pub struct TiledGridSlice<'a, T: 'a, S: 'a + CoordSystem + Clone = XThenY> {
    grid: &'a Grid<T, S>,
    offset: Coord,
    size: Size,
    orientation: Orientation,
}

pub struct TiledGridSliceIter<'a, T: 'a, S: 'a + CoordSystem + Clone> {
    grid: &'a TiledGridSlice<'a, T, S>,
    coord_iter: XThenYIter,
}

impl<'a, T, S> Iterator for TiledGridSliceIter<'a, T, S>
where
    S: CoordSystem + Clone,
{
    type Item = &'a T;
    fn next(&mut self) -> Option<Self::Item> {
        self.coord_iter
            .next()
            .map(|coord| self.grid.get_valid(coord))
    }
}

impl<'a, T, S> TiledGridSlice<'a, T, S>
where
    S: CoordSystem + Clone,
{
    pub fn new(
        grid: &'a Grid<T, S>,
        offset: Coord,
        size: Size,
        orientation: Orientation,
    ) -> Self {
        TiledGridSlice {
            grid,
            offset,
            size,
            orientation,
        }
    }
    pub fn size(&self) -> Size {
        self.size
    }
    fn get_valid(&self, coord: Coord) -> &'a T {
        let transformed_coord = self.orientation.transform_coord(self.size, coord);
        self.grid.get_tiled(self.offset + transformed_coord)
    }
    pub fn get_checked(&self, coord: Coord) -> &'a T {
        if coord.is_valid(self.size) {
            self.get_valid(coord)
        } else {
            panic!("coord is out of bounds");
        }
    }
    pub fn offset(&self) -> Coord {
        self.offset
    }
    pub fn iter(&self) -> TiledGridSliceIter<T, S> {
        TiledGridSliceIter {
            grid: self,
            coord_iter: XThenYIter::from(self.size),
        }
    }
}

impl<'a, T: Hash, S> Hash for TiledGridSlice<'a, T, S>
where
    S: CoordSystem + Clone,
{
    fn hash<H: Hasher>(&self, state: &mut H) {
        for value in self.iter() {
            value.hash(state);
        }
    }
}

impl<'a, T: PartialEq, S> PartialEq for TiledGridSlice<'a, T, S>
where
    S: CoordSystem + Clone,
{
    fn eq(&self, other: &Self) -> bool {
        self.size == other.size && self.iter().zip(other.iter()).all(|(s, o)| s.eq(o))
    }
}
impl<'a, T: Eq, S> Eq for TiledGridSlice<'a, T, S> where S: CoordSystem + Clone {}

#[cfg(test)]
mod test {
    use super::*;
    use coord_2d::{Coord, Size};
    use orientation::Orientation;
    use std::collections::HashSet;

    #[test]
    fn tiling() {
        let grid = Grid::new_fn(Size::new(4, 4), |coord| coord);
        let slice = TiledGridSlice::new(
            &grid,
            Coord::new(-1, -1),
            Size::new(2, 2),
            Orientation::Original,
        );
        let value = *slice.get_valid(Coord::new(0, 1));
        assert_eq!(value, Coord::new(3, 0));
    }
    #[test]
    fn tiled_grid_slice_hash() {
        let mut grid = Grid::new_fn(Size::new(4, 4), |_| 0);
        *grid.get_mut(Coord::new(1, 3)).unwrap() = 1;
        let size = Size::new(2, 2);
        let a = TiledGridSlice::new(&grid, Coord::new(0, 0), size, Orientation::Original);
        let b = TiledGridSlice::new(&grid, Coord::new(2, 2), size, Orientation::Original);
        let c = TiledGridSlice::new(&grid, Coord::new(0, 2), size, Orientation::Original);
        let d =
            TiledGridSlice::new(&grid, Coord::new(1, 2), size, Orientation::Clockwise270);
        let mut set = HashSet::new();
        set.insert(a);
        set.insert(b);
        set.insert(c);
        set.insert(d);
        assert_eq!(set.len(), 2);
    }
}