kdtree_ray/
aabb.rs

1use crate::Point3;
2
3/// Axis-aligned bounding box is defined by two positions.
4///
5/// **Note**: The first position is expected to be the minimum bound and the second
6/// the maximum bound.
7///
8/// The animated GIF below shows a graphic example of an AABB that adapts its
9/// size to fit the rotating entity. The box constantly changes dimensions to
10/// snugly fit the entity contained inside.
11///
12/// ![Gif describing an AABB](https://media.prod.mdn.mozit.cloud/attachments/2015/10/16/11799/57dfaf5508784d6b9c5fe77c0df49a54/rotating_knot.gif)
13#[derive(Clone, Debug)]
14pub struct AABB {
15    /// Minimum position
16    pub min: Point3,
17    /// Maximum position
18    pub max: Point3,
19}
20
21impl Default for AABB {
22    fn default() -> Self {
23        Self::empty()
24    }
25}
26
27impl AABB {
28    /// Create an new AABB from two points.
29    pub fn new(min: Point3, max: Point3) -> Self {
30        Self { min, max }
31    }
32
33    /// Create an empty AABB.
34    pub fn empty() -> Self {
35        Self::new(
36            Point3::new(f32::INFINITY, f32::INFINITY, f32::INFINITY),
37            Point3::new(f32::NEG_INFINITY, f32::NEG_INFINITY, f32::NEG_INFINITY),
38        )
39    }
40
41    /// Compute AABB volume
42    pub fn volume(&self) -> f32 {
43        (self.max.x - self.min.x) * (self.max.y - self.min.y) * (self.max.z - self.min.z)
44    }
45
46    /// Compute AABB surface
47    pub fn surface(&self) -> f32 {
48        let dx = self.max.x - self.min.x;
49        let dy = self.max.y - self.min.y;
50        let dz = self.max.z - self.min.z;
51        2.0 * (dx * dy + dx * dz + dy * dz)
52    }
53
54    /// Merge another AABB into this one.
55    pub fn merge(&mut self, other: &Self) {
56        self.min = Point3::new(
57            self.min.x.min(other.min.x),
58            self.min.y.min(other.min.y),
59            self.min.z.min(other.min.z),
60        );
61        self.max = Point3::new(
62            self.max.x.max(other.max.x),
63            self.max.y.max(other.max.y),
64            self.max.z.max(other.max.z),
65        );
66    }
67}
68
69/// Your shapes needs to implement `Bounded` trait to build a KD-tree around it.
70pub trait Bounded {
71    /// This function return the **Axis-aligned bounding boxes**
72    /// (`AABB`) of the object.
73    ///
74    /// For more information check [AABB](type.AABB.html).
75    fn bound(&self) -> AABB;
76}
kdtree_ray/aabb.rs

kdtree_ray/
aabb.rs
