Implement bounding volume intersections (#11439)

# Objective

#10946 added bounding volume types and an `IntersectsVolume` trait, but
didn't actually implement intersections between bounding volumes.

This PR implements AABB-AABB, circle-circle / sphere-sphere, and
AABB-circle / AABB-sphere intersections.

## Solution

Implement `IntersectsVolume` for bounding volume pairs. I also added
`closest_point` methods to return the closest point on the surface /
inside of bounding volumes. This is used for AABB-circle / AABB-sphere
intersections.

---------

Co-authored-by: IQuick 143 <IQuick143cz@gmail.com>
This commit is contained in:
Joona Aalto 2024-01-22 19:55:59 +02:00 committed by GitHub
parent df063ab1ef
commit 6a3b059db9
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
4 changed files with 379 additions and 6 deletions

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@ -2,7 +2,7 @@ mod primitive_impls;
use glam::Mat2;
use super::BoundingVolume;
use super::{BoundingVolume, IntersectsVolume};
use crate::prelude::Vec2;
/// Computes the geometric center of the given set of points.
@ -80,6 +80,16 @@ impl Aabb2d {
let radius = self.min.distance(self.max) / 2.0;
BoundingCircle::new(self.center(), radius)
}
/// Finds the point on the AABB that is closest to the given `point`.
///
/// If the point is outside the AABB, the returned point will be on the perimeter of the AABB.
/// Otherwise, it will be inside the AABB and returned as is.
#[inline(always)]
pub fn closest_point(&self, point: Vec2) -> Vec2 {
// Clamp point coordinates to the AABB
point.clamp(self.min, self.max)
}
}
impl BoundingVolume for Aabb2d {
@ -139,10 +149,32 @@ impl BoundingVolume for Aabb2d {
}
}
impl IntersectsVolume<Self> for Aabb2d {
#[inline(always)]
fn intersects(&self, other: &Self) -> bool {
let x_overlaps = self.min.x <= other.max.x && self.max.x >= other.min.x;
let y_overlaps = self.min.y <= other.max.y && self.max.y >= other.min.y;
x_overlaps && y_overlaps
}
}
impl IntersectsVolume<BoundingCircle> for Aabb2d {
#[inline(always)]
fn intersects(&self, circle: &BoundingCircle) -> bool {
let closest_point = self.closest_point(circle.center);
let distance_squared = circle.center.distance_squared(closest_point);
let radius_squared = circle.radius().powi(2);
distance_squared <= radius_squared
}
}
#[cfg(test)]
mod aabb2d_tests {
use super::Aabb2d;
use crate::{bounding::BoundingVolume, Vec2};
use crate::{
bounding::{BoundingCircle, BoundingVolume, IntersectsVolume},
Vec2,
};
#[test]
fn center() {
@ -244,6 +276,53 @@ mod aabb2d_tests {
assert!(a.contains(&shrunk));
assert!(!shrunk.contains(&a));
}
#[test]
fn closest_point() {
let aabb = Aabb2d {
min: Vec2::NEG_ONE,
max: Vec2::ONE,
};
assert_eq!(aabb.closest_point(Vec2::X * 10.0), Vec2::X);
assert_eq!(aabb.closest_point(Vec2::NEG_ONE * 10.0), Vec2::NEG_ONE);
assert_eq!(
aabb.closest_point(Vec2::new(0.25, 0.1)),
Vec2::new(0.25, 0.1)
);
}
#[test]
fn intersect_aabb() {
let aabb = Aabb2d {
min: Vec2::NEG_ONE,
max: Vec2::ONE,
};
assert!(aabb.intersects(&aabb));
assert!(aabb.intersects(&Aabb2d {
min: Vec2::new(0.5, 0.5),
max: Vec2::new(2.0, 2.0),
}));
assert!(aabb.intersects(&Aabb2d {
min: Vec2::new(-2.0, -2.0),
max: Vec2::new(-0.5, -0.5),
}));
assert!(!aabb.intersects(&Aabb2d {
min: Vec2::new(1.1, 0.0),
max: Vec2::new(2.0, 0.5),
}));
}
#[test]
fn intersect_bounding_circle() {
let aabb = Aabb2d {
min: Vec2::NEG_ONE,
max: Vec2::ONE,
};
assert!(aabb.intersects(&BoundingCircle::new(Vec2::ZERO, 1.0)));
assert!(aabb.intersects(&BoundingCircle::new(Vec2::ONE * 1.5, 1.0)));
assert!(aabb.intersects(&BoundingCircle::new(Vec2::NEG_ONE * 1.5, 1.0)));
assert!(!aabb.intersects(&BoundingCircle::new(Vec2::ONE * 1.75, 1.0)));
}
}
use crate::primitives::Circle;
@ -305,6 +384,15 @@ impl BoundingCircle {
max: self.center + Vec2::splat(self.radius()),
}
}
/// Finds the point on the bounding circle that is closest to the given `point`.
///
/// If the point is outside the circle, the returned point will be on the perimeter of the circle.
/// Otherwise, it will be inside the circle and returned as is.
#[inline(always)]
pub fn closest_point(&self, point: Vec2) -> Vec2 {
self.circle.closest_point(point - self.center) + self.center
}
}
impl BoundingVolume for BoundingCircle {
@ -363,10 +451,29 @@ impl BoundingVolume for BoundingCircle {
}
}
impl IntersectsVolume<Self> for BoundingCircle {
#[inline(always)]
fn intersects(&self, other: &Self) -> bool {
let center_distance_squared = self.center.distance_squared(other.center);
let radius_sum_squared = (self.radius() + other.radius()).powi(2);
center_distance_squared <= radius_sum_squared
}
}
impl IntersectsVolume<Aabb2d> for BoundingCircle {
#[inline(always)]
fn intersects(&self, aabb: &Aabb2d) -> bool {
aabb.intersects(self)
}
}
#[cfg(test)]
mod bounding_circle_tests {
use super::BoundingCircle;
use crate::{bounding::BoundingVolume, Vec2};
use crate::{
bounding::{BoundingVolume, IntersectsVolume},
Vec2,
};
#[test]
fn area() {
@ -443,4 +550,27 @@ mod bounding_circle_tests {
assert!(a.contains(&shrunk));
assert!(!shrunk.contains(&a));
}
#[test]
fn closest_point() {
let circle = BoundingCircle::new(Vec2::ZERO, 1.0);
assert_eq!(circle.closest_point(Vec2::X * 10.0), Vec2::X);
assert_eq!(
circle.closest_point(Vec2::NEG_ONE * 10.0),
Vec2::NEG_ONE.normalize()
);
assert_eq!(
circle.closest_point(Vec2::new(0.25, 0.1)),
Vec2::new(0.25, 0.1)
);
}
#[test]
fn intersect_bounding_circle() {
let circle = BoundingCircle::new(Vec2::ZERO, 1.0);
assert!(circle.intersects(&BoundingCircle::new(Vec2::ZERO, 1.0)));
assert!(circle.intersects(&BoundingCircle::new(Vec2::ONE * 1.25, 1.0)));
assert!(circle.intersects(&BoundingCircle::new(Vec2::NEG_ONE * 1.25, 1.0)));
assert!(!circle.intersects(&BoundingCircle::new(Vec2::ONE * 1.5, 1.0)));
}
}

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@ -1,6 +1,6 @@
mod primitive_impls;
use super::BoundingVolume;
use super::{BoundingVolume, IntersectsVolume};
use crate::prelude::{Quat, Vec3};
/// Computes the geometric center of the given set of points.
@ -74,6 +74,16 @@ impl Aabb3d {
let radius = self.min.distance(self.max) / 2.0;
BoundingSphere::new(self.center(), radius)
}
/// Finds the point on the AABB that is closest to the given `point`.
///
/// If the point is outside the AABB, the returned point will be on the surface of the AABB.
/// Otherwise, it will be inside the AABB and returned as is.
#[inline(always)]
pub fn closest_point(&self, point: Vec3) -> Vec3 {
// Clamp point coordinates to the AABB
point.clamp(self.min, self.max)
}
}
impl BoundingVolume for Aabb3d {
@ -135,10 +145,33 @@ impl BoundingVolume for Aabb3d {
}
}
impl IntersectsVolume<Self> for Aabb3d {
#[inline(always)]
fn intersects(&self, other: &Self) -> bool {
let x_overlaps = self.min.x <= other.max.x && self.max.x >= other.min.x;
let y_overlaps = self.min.y <= other.max.y && self.max.y >= other.min.y;
let z_overlaps = self.min.z <= other.max.z && self.max.z >= other.min.z;
x_overlaps && y_overlaps && z_overlaps
}
}
impl IntersectsVolume<BoundingSphere> for Aabb3d {
#[inline(always)]
fn intersects(&self, sphere: &BoundingSphere) -> bool {
let closest_point = self.closest_point(sphere.center);
let distance_squared = sphere.center.distance_squared(closest_point);
let radius_squared = sphere.radius().powi(2);
distance_squared <= radius_squared
}
}
#[cfg(test)]
mod aabb3d_tests {
use super::Aabb3d;
use crate::{bounding::BoundingVolume, Vec3};
use crate::{
bounding::{BoundingSphere, BoundingVolume, IntersectsVolume},
Vec3,
};
#[test]
fn center() {
@ -239,6 +272,53 @@ mod aabb3d_tests {
assert!(a.contains(&shrunk));
assert!(!shrunk.contains(&a));
}
#[test]
fn closest_point() {
let aabb = Aabb3d {
min: Vec3::NEG_ONE,
max: Vec3::ONE,
};
assert_eq!(aabb.closest_point(Vec3::X * 10.0), Vec3::X);
assert_eq!(aabb.closest_point(Vec3::NEG_ONE * 10.0), Vec3::NEG_ONE);
assert_eq!(
aabb.closest_point(Vec3::new(0.25, 0.1, 0.3)),
Vec3::new(0.25, 0.1, 0.3)
);
}
#[test]
fn intersect_aabb() {
let aabb = Aabb3d {
min: Vec3::NEG_ONE,
max: Vec3::ONE,
};
assert!(aabb.intersects(&aabb));
assert!(aabb.intersects(&Aabb3d {
min: Vec3::splat(0.5),
max: Vec3::splat(2.0),
}));
assert!(aabb.intersects(&Aabb3d {
min: Vec3::splat(-2.0),
max: Vec3::splat(-0.5),
}));
assert!(!aabb.intersects(&Aabb3d {
min: Vec3::new(1.1, 0.0, 0.0),
max: Vec3::new(2.0, 0.5, 0.25),
}));
}
#[test]
fn intersect_bounding_sphere() {
let aabb = Aabb3d {
min: Vec3::NEG_ONE,
max: Vec3::ONE,
};
assert!(aabb.intersects(&BoundingSphere::new(Vec3::ZERO, 1.0)));
assert!(aabb.intersects(&BoundingSphere::new(Vec3::ONE * 1.5, 1.0)));
assert!(aabb.intersects(&BoundingSphere::new(Vec3::NEG_ONE * 1.5, 1.0)));
assert!(!aabb.intersects(&BoundingSphere::new(Vec3::ONE * 1.75, 1.0)));
}
}
use crate::primitives::Sphere;
@ -296,6 +376,15 @@ impl BoundingSphere {
max: self.center + Vec3::splat(self.radius()),
}
}
/// Finds the point on the bounding sphere that is closest to the given `point`.
///
/// If the point is outside the sphere, the returned point will be on the surface of the sphere.
/// Otherwise, it will be inside the sphere and returned as is.
#[inline(always)]
pub fn closest_point(&self, point: Vec3) -> Vec3 {
self.sphere.closest_point(point - self.center) + self.center
}
}
impl BoundingVolume for BoundingSphere {
@ -364,10 +453,29 @@ impl BoundingVolume for BoundingSphere {
}
}
impl IntersectsVolume<Self> for BoundingSphere {
#[inline(always)]
fn intersects(&self, other: &Self) -> bool {
let center_distance_squared = self.center.distance_squared(other.center);
let radius_sum_squared = (self.radius() + other.radius()).powi(2);
center_distance_squared <= radius_sum_squared
}
}
impl IntersectsVolume<Aabb3d> for BoundingSphere {
#[inline(always)]
fn intersects(&self, aabb: &Aabb3d) -> bool {
aabb.intersects(self)
}
}
#[cfg(test)]
mod bounding_sphere_tests {
use super::BoundingSphere;
use crate::{bounding::BoundingVolume, Vec3};
use crate::{
bounding::{BoundingVolume, IntersectsVolume},
Vec3,
};
#[test]
fn area() {
@ -444,4 +552,27 @@ mod bounding_sphere_tests {
assert!(a.contains(&shrunk));
assert!(!shrunk.contains(&a));
}
#[test]
fn closest_point() {
let sphere = BoundingSphere::new(Vec3::ZERO, 1.0);
assert_eq!(sphere.closest_point(Vec3::X * 10.0), Vec3::X);
assert_eq!(
sphere.closest_point(Vec3::NEG_ONE * 10.0),
Vec3::NEG_ONE.normalize()
);
assert_eq!(
sphere.closest_point(Vec3::new(0.25, 0.1, 0.3)),
Vec3::new(0.25, 0.1, 0.3)
);
}
#[test]
fn intersect_bounding_sphere() {
let sphere = BoundingSphere::new(Vec3::ZERO, 1.0);
assert!(sphere.intersects(&BoundingSphere::new(Vec3::ZERO, 1.0)));
assert!(sphere.intersects(&BoundingSphere::new(Vec3::ONE * 1.1, 1.0)));
assert!(sphere.intersects(&BoundingSphere::new(Vec3::NEG_ONE * 1.1, 1.0)));
assert!(!sphere.intersects(&BoundingSphere::new(Vec3::ONE * 1.2, 1.0)));
}
}

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@ -87,6 +87,27 @@ pub struct Circle {
}
impl Primitive2d for Circle {}
impl Circle {
/// Finds the point on the circle that is closest to the given `point`.
///
/// If the point is outside the circle, the returned point will be on the perimeter of the circle.
/// Otherwise, it will be inside the circle and returned as is.
#[inline(always)]
pub fn closest_point(&self, point: Vec2) -> Vec2 {
let distance_squared = point.length_squared();
if distance_squared <= self.radius.powi(2) {
// The point is inside the circle.
point
} else {
// The point is outside the circle.
// Find the closest point on the perimeter of the circle.
let dir_to_point = point / distance_squared.sqrt();
self.radius * dir_to_point
}
}
}
/// An ellipse primitive
#[derive(Clone, Copy, Debug)]
pub struct Ellipse {
@ -358,6 +379,16 @@ impl Rectangle {
half_size: size / 2.,
}
}
/// Finds the point on the rectangle that is closest to the given `point`.
///
/// If the point is outside the rectangle, the returned point will be on the perimeter of the rectangle.
/// Otherwise, it will be inside the rectangle and returned as is.
#[inline(always)]
pub fn closest_point(&self, point: Vec2) -> Vec2 {
// Clamp point coordinates to the rectangle
point.clamp(-self.half_size, self.half_size)
}
}
/// A polygon with N vertices.
@ -549,4 +580,29 @@ mod tests {
< 1e-7,
);
}
#[test]
fn rectangle_closest_point() {
let rectangle = Rectangle::new(2.0, 2.0);
assert_eq!(rectangle.closest_point(Vec2::X * 10.0), Vec2::X);
assert_eq!(rectangle.closest_point(Vec2::NEG_ONE * 10.0), Vec2::NEG_ONE);
assert_eq!(
rectangle.closest_point(Vec2::new(0.25, 0.1)),
Vec2::new(0.25, 0.1)
);
}
#[test]
fn circle_closest_point() {
let circle = Circle { radius: 1.0 };
assert_eq!(circle.closest_point(Vec2::X * 10.0), Vec2::X);
assert_eq!(
circle.closest_point(Vec2::NEG_ONE * 10.0),
Vec2::NEG_ONE.normalize()
);
assert_eq!(
circle.closest_point(Vec2::new(0.25, 0.1)),
Vec2::new(0.25, 0.1)
);
}
}

View File

@ -91,6 +91,27 @@ pub struct Sphere {
}
impl Primitive3d for Sphere {}
impl Sphere {
/// Finds the point on the sphere that is closest to the given `point`.
///
/// If the point is outside the sphere, the returned point will be on the surface of the sphere.
/// Otherwise, it will be inside the sphere and returned as is.
#[inline(always)]
pub fn closest_point(&self, point: Vec3) -> Vec3 {
let distance_squared = point.length_squared();
if distance_squared <= self.radius.powi(2) {
// The point is inside the sphere.
point
} else {
// The point is outside the sphere.
// Find the closest point on the surface of the sphere.
let dir_to_point = point / distance_squared.sqrt();
self.radius * dir_to_point
}
}
}
/// An unbounded plane in 3D space. It forms a separating surface through the origin,
/// stretching infinitely far
#[derive(Clone, Copy, Debug)]
@ -245,6 +266,16 @@ impl Cuboid {
half_size: size / 2.,
}
}
/// Finds the point on the cuboid that is closest to the given `point`.
///
/// If the point is outside the cuboid, the returned point will be on the surface of the cuboid.
/// Otherwise, it will be inside the cuboid and returned as is.
#[inline(always)]
pub fn closest_point(&self, point: Vec3) -> Vec3 {
// Clamp point coordinates to the cuboid
point.clamp(-self.half_size, self.half_size)
}
}
/// A cylinder primitive
@ -433,4 +464,29 @@ mod test {
Ok((Direction3d::X, 6.5))
);
}
#[test]
fn cuboid_closest_point() {
let cuboid = Cuboid::new(2.0, 2.0, 2.0);
assert_eq!(cuboid.closest_point(Vec3::X * 10.0), Vec3::X);
assert_eq!(cuboid.closest_point(Vec3::NEG_ONE * 10.0), Vec3::NEG_ONE);
assert_eq!(
cuboid.closest_point(Vec3::new(0.25, 0.1, 0.3)),
Vec3::new(0.25, 0.1, 0.3)
);
}
#[test]
fn sphere_closest_point() {
let sphere = Sphere { radius: 1.0 };
assert_eq!(sphere.closest_point(Vec3::X * 10.0), Vec3::X);
assert_eq!(
sphere.closest_point(Vec3::NEG_ONE * 10.0),
Vec3::NEG_ONE.normalize()
);
assert_eq!(
sphere.closest_point(Vec3::new(0.25, 0.1, 0.3)),
Vec3::new(0.25, 0.1, 0.3)
);
}
}