mirror of
https://gitlab.com/veloren/veloren.git
synced 2024-08-30 18:12:32 +00:00
57 lines
1.8 KiB
Rust
57 lines
1.8 KiB
Rust
use vek::*;
|
|
|
|
/// An iterator of coordinates that create a rectangular spiral out from the
|
|
/// origin
|
|
#[derive(Clone)]
|
|
pub struct Spiral2d {
|
|
layer: i32,
|
|
i: i32,
|
|
}
|
|
|
|
impl Spiral2d {
|
|
#[allow(clippy::new_without_default)]
|
|
/// Creates a new spiral starting at the origin
|
|
pub fn new() -> Self { Self { layer: 0, i: 0 } }
|
|
|
|
/// Creates an iterator over points in a spiral starting at the origin and
|
|
/// going out to some radius
|
|
pub fn with_radius(radius: i32) -> impl Iterator<Item = Vec2<i32>> {
|
|
Self::new()
|
|
.take((radius * 2 + 1).pow(2) as usize)
|
|
.filter(move |pos| pos.magnitude_squared() < (radius + 1).pow(2))
|
|
}
|
|
|
|
/// Creates an iterator over points in the edge of a circle of some radius
|
|
pub fn with_edge_radius(radius: i32) -> impl Iterator<Item = Vec2<i32>> {
|
|
Self::new()
|
|
.take((radius * 2 + 1).pow(2) as usize)
|
|
.filter(move |pos| pos.magnitude_squared() < (radius + 1).pow(2))
|
|
.filter(move |pos| pos.magnitude_squared() >= radius.pow(2))
|
|
}
|
|
}
|
|
|
|
impl Iterator for Spiral2d {
|
|
type Item = Vec2<i32>;
|
|
|
|
#[allow(clippy::erasing_op, clippy::identity_op)]
|
|
fn next(&mut self) -> Option<Self::Item> {
|
|
let layer_size = (self.layer * 8 + 4 * self.layer.min(1) - 4).max(1);
|
|
if self.i >= layer_size {
|
|
self.layer += 1;
|
|
self.i = 0;
|
|
}
|
|
let layer_size = (self.layer * 8 + 4 * self.layer.min(1) - 4).max(1);
|
|
|
|
let pos = Vec2::new(
|
|
-self.layer + (self.i - (layer_size / 4) * 0).max(0).min(self.layer * 2)
|
|
- (self.i - (layer_size / 4) * 2).max(0).min(self.layer * 2),
|
|
-self.layer + (self.i - (layer_size / 4) * 1).max(0).min(self.layer * 2)
|
|
- (self.i - (layer_size / 4) * 3).max(0).min(self.layer * 2),
|
|
);
|
|
|
|
self.i += 1;
|
|
|
|
Some(pos)
|
|
}
|
|
}
|