#[derive(PartialEq, Clone, Copy, Debug)]
struct Voxel {
    r: u8,
    g: u8,
    b: u8
}

const AIR_VOXEL: Voxel = Voxel { r: 0, g: 0, b: 0 };

struct VoxelMap {
    data: Vec<Voxel>,
    width: usize,
    height: usize,
    depth: usize
}

impl VoxelMap {
    fn new(width: usize, height: usize, depth: usize) -> Self {
        Self {
            data: vec![AIR_VOXEL; width * height * depth],
            width,
            height,
            depth
        }
    }

    fn set(&mut self, x: usize, y: usize, z: usize, voxel: Voxel) {
        if x < self.width && y < self.height && z < self.depth {
            self.data[x + y * self.width + z * self.width * self.height] = voxel;
        }
    }

    fn get(&self, x: usize, y: usize, z: usize) -> Voxel {
        if x < self.width && y < self.height && z < self.depth {
            self.data[x + y * self.width + z * self.width * self.height]
        } else {
            AIR_VOXEL
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_voxel_map() {
        let mut map = VoxelMap::new(10, 10, 10);
        map.set(0, 0, 0, Voxel { r: 255, g: 0, b: 0 });
        assert_eq!(map.get(0, 0, 0), Voxel { r: 255, g: 0, b: 0 });
        assert_eq!(map.get(1, 0, 0), AIR_VOXEL);
        assert_eq!(map.get(0, 1, 0), AIR_VOXEL);
        assert_eq!(map.get(0, 0, 1), AIR_VOXEL);
        assert_eq!(map.get(10, 0, 0), AIR_VOXEL);
        assert_eq!(map.get(0, 10, 0), AIR_VOXEL);
        assert_eq!(map.get(0, 0, 10), AIR_VOXEL);

        // out of bounds
        assert_eq!(map.get(0, 0, 11), AIR_VOXEL);
    }
}