Merge branch 'add-beevee' into 'master'

Add beevee

See merge request EPITA_bruno.belanyi/image/ing2/pathtracer!4

Cargo.toml

@@ -1,38 +1,6 @@
-[package]
+[workspace]
-name = "pathtracer"
+
-version = "0.1.0"
+members = [
-authors = [
+    "beevee",
-    "Bruno BELANYI <brunobelanyi@gmail.com>",
+    "pathtracer",
-    "Antoine Martin <antoine97.martin@gmail.com>"
 ]
-edition = "2018"
-description = "A pathtracer written in Rust"
-
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
-
-[lib]
-name = "pathtracer"
-path = "src/lib.rs"
-
-[[bin]]
-name = "pathtracer"
-path = "src/main.rs"
-
-[dependencies]
-bvh = "0.3.2"
-derive_more = "0.99.3"
-enum_dispatch = "0.2.1"
-image = "0.23.0"
-indicatif = "0.14.0"
-rand = "0.7"
-rayon = "1.3.0"
-serde_yaml = "0.8"
-structopt = "0.3"
-
-[dependencies.nalgebra]
-version = "0.20.0"
-features = ["serde-serialize"]
-
-[dependencies.serde]
-version = "1.0"
-features = ["derive"]

beevee/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "beevee"
+version = "0.1.0"
+authors = ["Bruno BELANYI <brunobelanyi@gmail.com>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+nalgebra = "0.20"
+pdqselect = "0.1.0"

beevee/src/aabb/bounded.rs

@@ -0,0 +1,63 @@
+use super::AABB;
+use crate::Point;
+
+/// A trait for objects that can be bounded using an [`AABB`]
+///
+/// [`AABB`]: struct.AABB.html
+pub trait Bounded {
+    /// Return the [`AABB`] surrounding self.
+    ///
+    /// [`AABB`]: struct.AABB.html
+    fn aabb(&self) -> AABB;
+    /// Return the centroid of self.
+    fn centroid(&self) -> Point;
+}
+
+/// Implementation of [`Bounded`] for [`AABB`]
+///
+/// [`Bounded`]: trait.Bounded.html
+/// [`AABB`]: struct.Point.html
+///
+/// # Examples
+/// ```
+/// use beevee::Point;
+/// use beevee::aabb::{AABB, Bounded};
+///
+/// let low = Point::new(0., 0., 0.);
+/// let high = Point::new(1., 2., 3.);
+/// let aabb = AABB::with_bounds(low, high);
+/// assert_eq!(aabb, aabb.aabb());
+/// ```
+impl Bounded for AABB {
+    fn aabb(&self) -> AABB {
+        *self
+    }
+
+    fn centroid(&self) -> Point {
+        self.centroid()
+    }
+}
+
+/// Implementation of [`Bounded`] for [`Point`]
+///
+/// [`Bounded`]: trait.Bounded.html
+/// [`Point`]: ../type.Point.html
+///
+/// # Examples
+/// ```
+/// use beevee::Point;
+/// use beevee::aabb::Bounded;
+///
+/// let point = Point::new(1., 2., 3.);
+/// let aabb = point.aabb();
+/// assert!(aabb.contains(&point));
+/// ```
+impl Bounded for Point {
+    fn aabb(&self) -> AABB {
+        AABB::with_bounds(*self, *self)
+    }
+
+    fn centroid(&self) -> Point {
+        *self
+    }
+}

beevee/src/aabb/bounding_box.rs

@@ -0,0 +1,444 @@
+//! An Axis-Alighned Bounding Box.
+
+use crate::{Axis, Point, Vector};
+use std::fmt::{Display, Formatter, Result};
+
+/// An Axis-Aligned Bounding Box.
+#[derive(Copy, Clone, Debug, PartialEq)]
+pub struct AABB {
+    /// The corner with the lowest (x, y, z) coordinates.
+    pub low: Point,
+    /// The corner with the highest (x, y, z) coordinates.
+    pub high: Point,
+}
+
+impl AABB {
+    /// Create a new empty [`AABB`]
+    ///
+    /// [`AABB`]: struct.AABB.html
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use beevee::Point;
+    /// use beevee::aabb::AABB;
+    ///
+    /// let aabb = AABB::empty();
+    ///
+    /// // Here for teh origin, but also true for any other point
+    /// let point = Point::origin();
+    ///
+    /// assert!(!aabb.contains(&point));
+    /// ```
+    #[must_use]
+    pub fn empty() -> Self {
+        let lowest = std::f32::NEG_INFINITY;
+        let highest = std::f32::INFINITY;
+        AABB {
+            low: Point::new(highest, highest, highest),
+            high: Point::new(lowest, lowest, lowest),
+        }
+    }
+
+    /// Create a new empty [`AABB`]
+    ///
+    /// [`AABB`]: struct.AABB.html
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # use beevee::Point;
+    /// # use beevee::aabb::AABB;
+    /// #
+    /// let low = Point::new(0., 0., 0.);
+    /// let high = Point::new(1., 1., 1.);
+    /// let aabb = AABB::with_bounds(low, high);
+    ///
+    /// assert_eq!(aabb, AABB::with_bounds(low, high));
+    /// ```
+    #[must_use]
+    pub fn with_bounds(low: Point, high: Point) -> Self {
+        debug_assert!(low.x <= high.x);
+        debug_assert!(low.y <= high.y);
+        debug_assert!(low.z <= high.z);
+        AABB { low, high }
+    }
+
+    /// Return a new bounding box containing both `self` and the new [`Point`]
+    ///
+    /// [`Point`]: ../type.Point.html
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # use beevee::Point;
+    /// # use beevee::aabb::AABB;
+    /// #
+    /// let aabb = AABB::empty();
+    /// let new_aabb = aabb.grow(&Point::origin());
+    ///
+    /// assert_eq!(new_aabb, AABB::with_bounds(Point::origin(), Point::origin()));
+    /// ```
+    #[must_use]
+    pub fn grow(&self, point: &Point) -> Self {
+        let mut ans = *self;
+        ans.grow_mut(point);
+        ans
+    }
+
+    /// Grow the bounding box to accomodate a new  [`Point`].
+    ///
+    /// [`Point`]: ../type.Point.html
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # use beevee::Point;
+    /// # use beevee::aabb::AABB;
+    /// #
+    /// let mut aabb = AABB::empty();
+    /// aabb.grow_mut(&Point::origin());
+    ///
+    /// assert_eq!(aabb, AABB::with_bounds(Point::origin(), Point::origin()));
+    /// ```
+    pub fn grow_mut(&mut self, point: &Point) -> &mut Self {
+        // Update lowest bound
+        self.low.x = self.low.x.min(point.x);
+        self.low.y = self.low.y.min(point.y);
+        self.low.z = self.low.z.min(point.z);
+        // Update higher bound
+        self.high.x = self.high.x.max(point.x);
+        self.high.y = self.high.y.max(point.y);
+        self.high.z = self.high.z.max(point.z);
+        // Return self for method chaining
+        self
+    }
+
+    /// Return true if the bounding box contains the [`Point`], false otherwise
+    ///
+    /// [`Point`]: ../type.Point.html
+    ///
+    /// # Examples
+    /// ```
+    /// # use beevee::Point;
+    /// # use beevee::aabb::AABB;
+    /// #
+    /// let low = Point::new(0., 0., 0.);
+    /// let high = Point::new(1., 1., 1.);
+    /// let aabb = AABB::with_bounds(low, high);
+    ///
+    /// // It contains the whole box from low to high
+    /// assert!(aabb.contains(&low));
+    /// assert!(aabb.contains(&high));
+    /// assert!(aabb.contains(&Point::new(0.5, 0.5, 0.5)));
+    ///
+    /// // And doesn't contain anything else
+    /// assert!(!aabb.contains(&Point::new(-1., -1., -1.)));
+    /// assert!(!aabb.contains(&Point::new(1.1, 0., 0.)));
+    /// assert!(!aabb.contains(&Point::new(2., -2., 0.)));
+    /// ```
+    pub fn contains(&self, point: &Point) -> bool {
+        (self.low.x..=self.high.x).contains(&point.x)
+            && (self.low.y..=self.high.y).contains(&point.y)
+            && (self.low.z..=self.high.z).contains(&point.z)
+    }
+
+    /// Return a new `AABB` which encloses `self` and the other [`AABB`].
+    ///
+    /// [`AABB`]: struct.AABB.html
+    ///
+    /// # Examples
+    /// ```
+    /// # use beevee::Point;
+    /// # use beevee::aabb::AABB;
+    /// #
+    /// let low = Point::new(0., 0., 0.);
+    /// let high = Point::new(1., 1., 1.);
+    /// let aabb = AABB::empty();
+    /// let other = AABB::with_bounds(low, high);
+    ///
+    ///  // Grow the AABB to enclose the other one.
+    ///  let union = aabb.union(&other);
+    ///
+    /// // The result is now the union of an empty bounding box and the other one.
+    ///  assert_eq!(union, other);
+    /// ```
+    pub fn union(&self, other: &Self) -> Self {
+        // Clone the first bounding box.
+        let mut ans = *self;
+        // Update the new bounding box.
+        ans.union_mut(other);
+        // Return the new bounding box.
+        ans
+    }
+
+    /// Grow `self` to enclose the other [`AABB`].
+    ///
+    /// [`AABB`]: struct.AABB.html
+    ///
+    /// # Examples
+    /// ```
+    /// # use beevee::Point;
+    /// # use beevee::aabb::AABB;
+    /// #
+    /// let low = Point::new(0., 0., 0.);
+    /// let high = Point::new(1., 1., 1.);
+    /// let mut aabb = AABB::empty();
+    /// let other = AABB::with_bounds(low, high);
+    ///
+    ///  // Grow the AABB to enclose the other one.
+    ///  aabb.union_mut(&other);
+    ///
+    /// // The bounding box has grown to become equal to other one.
+    ///  assert_eq!(aabb, other);
+    /// ```
+    pub fn union_mut(&mut self, other: &Self) -> &mut Self {
+        self.grow_mut(&other.low);
+        self.grow_mut(&other.high);
+        self
+    }
+
+    /// Return a vector correspondin to the diagonal from `low` to `high` for the [`AABB`].
+    ///
+    /// [`AABB`]: struct.AABB.html
+    ///
+    /// # Examples
+    /// ```
+    /// # use beevee::Point;
+    /// # use beevee::aabb::AABB;
+    /// #
+    /// let low = Point::new(0., 0., 0.);
+    /// let high = Point::new(1., 1., 1.);
+    /// let aabb = AABB::with_bounds(low, high);
+    ///
+    /// assert_eq!(aabb.diagonal(), high - low);
+    /// ```
+    pub fn diagonal(&self) -> Vector {
+        self.high - self.low
+    }
+
+    /// Return the center of the [`AABB`].
+    ///
+    /// [`AABB`]: struct.AABB.html
+    ///
+    /// # Examples
+    /// ```
+    /// # use beevee::Point;
+    /// # use beevee::aabb::AABB;
+    /// #
+    /// let low = Point::new(0., 0., 0.);
+    /// let high = Point::new(1., 1., 1.);
+    /// let aabb = AABB::with_bounds(low, high);
+    ///
+    /// assert_eq!(aabb.centroid(), low + (high - low) / 2.);
+    /// ```
+    pub fn centroid(&self) -> Point {
+        self.low + self.diagonal() / 2.
+    }
+
+    /// Return true if the [`AABB`] is empty, false otherwise.
+    /// [`AABB`]: struct.AABB.html
+    ///
+    /// # Examples
+    /// ```
+    /// # use beevee::Point;
+    /// # use beevee::aabb::AABB;
+    /// #
+    /// let low = Point::new(0., 0., 0.);
+    /// let high = Point::new(1., 1., 1.);
+    /// let not_empty = AABB::with_bounds(low, high);
+    /// let empty = AABB::empty();
+    ///
+    /// assert!(!not_empty.is_empty());
+    /// assert!(empty.is_empty());
+    /// ```
+    pub fn is_empty(&self) -> bool {
+        self.low.x > self.high.x || self.low.y > self.high.y || self.low.z > self.high.z
+    }
+
+    /// Return the total surface area of the [`AABB`].
+    ///
+    /// [`AABB`]: struct.AABB.html
+    ///
+    /// # Examples
+    /// ```
+    /// # use beevee::Point;
+    /// # use beevee::aabb::AABB;
+    /// #
+    /// let low = Point::new(0., 0., 0.);
+    /// let high = Point::new(1., 1., 1.);
+    /// let aabb = AABB::with_bounds(low, high);
+    ///
+    /// assert!((aabb.surface() - 6.).abs() < std::f32::EPSILON);
+    /// ```
+    pub fn surface(&self) -> f32 {
+        let diagonal = self.diagonal();
+        2. * (diagonal.x * diagonal.y + diagonal.x * diagonal.z + diagonal.y * diagonal.z)
+    }
+
+    /// Return the total volume of the [`AABB`].
+    ///
+    /// [`AABB`]: struct.AABB.html
+    ///
+    /// # Examples
+    /// ```
+    /// # use beevee::Point;
+    /// # use beevee::aabb::AABB;
+    /// #
+    /// let low = Point::new(0., 0., 0.);
+    /// let high = Point::new(1., 1., 1.);
+    /// let aabb = AABB::with_bounds(low, high);
+    ///
+    /// assert!((aabb.volume() - 1.).abs() < std::f32::EPSILON);
+    /// ```
+    pub fn volume(&self) -> f32 {
+        let diagonal = self.diagonal();
+        diagonal.x * diagonal.y * diagonal.z
+    }
+
+    /// Return the axis along which the [`AABB`] is the largest.
+    ///
+    /// [`AABB`]: struct.AABB.html
+    ///
+    /// # Examples
+    /// ```
+    /// # use beevee::Point;
+    /// # use beevee::aabb::AABB;
+    /// use beevee::Axis;
+    ///
+    /// let low = Point::new(0., 0., 0.);
+    /// let high = Point::new(3., 2., 1.);
+    /// let aabb = AABB::with_bounds(low, high);
+    ///
+    /// assert_eq!(aabb.largest_axis(), Axis::X);
+    /// ```
+    ///
+    /// ```
+    /// # use beevee::Point;
+    /// # use beevee::aabb::AABB;
+    /// use beevee::Axis;
+    ///
+    /// let low = Point::new(0., 0., 0.);
+    /// let high = Point::new(1., 1., 1.);
+    /// let aabb = AABB::with_bounds(low, high);
+    ///
+    /// // Prefers the X axis in case of a three-way tie, then the Y axis in a tie with Z
+    /// assert_eq!(aabb.largest_axis(), Axis::X);
+    /// ```
+    pub fn largest_axis(&self) -> Axis {
+        let diagonal = self.diagonal();
+        if diagonal.x >= diagonal.y && diagonal.x >= diagonal.z {
+            Axis::X
+        } else if diagonal.y >= diagonal.z {
+            Axis::Y
+        } else {
+            Axis::Z
+        }
+    }
+
+    /// Return the shortest distance from an [`AABB`] to a [`Point`].
+    ///
+    /// [`AABB`]: struct.AABB.html
+    /// [`AABB`]: ../type.Point.html
+    ///
+    /// # Examples
+    /// ```
+    /// # use beevee::Point;
+    /// # use beevee::aabb::AABB;
+    /// #
+    /// let low = Point::new(0., 0., 0.);
+    /// let high = Point::new(1., 1., 1.);
+    /// let aabb = AABB::with_bounds(low, high);
+    ///
+    /// assert!((aabb.distance_to_point(Point::new(-1., 0., 0.)) - 1.).abs() < std::f32::EPSILON);
+    /// ```
+    ///
+    /// ```
+    /// # use beevee::Point;
+    /// # use beevee::aabb::AABB;
+    /// #
+    /// let low = Point::new(0., 0., 0.);
+    /// let high = Point::new(1., 1., 1.);
+    /// let aabb = AABB::with_bounds(low, high);
+    ///
+    /// // Returns 0. when the point is contained by the AABB
+    /// assert!(aabb.distance_to_point(Point::new(0.5, 0.5, 0.5)).abs() < std::f32::EPSILON);
+    /// ```
+    pub fn distance_to_point(&self, point: Point) -> f32 {
+        f32::sqrt(self.sqdist_to_point(point))
+    }
+
+    /// Return the square of the shortest distance from an [`AABB`] to a [`Point`].
+    ///
+    /// [`AABB`]: struct.AABB.html
+    /// [`AABB`]: ../type.Point.html
+    ///
+    /// # Examples
+    /// ```
+    /// # use beevee::Point;
+    /// # use beevee::aabb::AABB;
+    /// #
+    /// let low = Point::new(0., 0., 0.);
+    /// let high = Point::new(1., 1., 1.);
+    /// let aabb = AABB::with_bounds(low, high);
+    ///
+    /// assert!((aabb.sqdist_to_point(Point::new(-1., 0., 0.)) - 1.).abs() < std::f32::EPSILON);
+    /// ```
+    ///
+    /// ```
+    /// # use beevee::Point;
+    /// # use beevee::aabb::AABB;
+    /// #
+    /// let low = Point::new(0., 0., 0.);
+    /// let high = Point::new(1., 1., 1.);
+    /// let aabb = AABB::with_bounds(low, high);
+    ///
+    /// // Returns 0. when the point is contained by the AABB
+    /// assert!(aabb.sqdist_to_point(Point::new(0.5, 0.5, 0.5)).abs() < std::f32::EPSILON);
+    /// ```
+    pub fn sqdist_to_point(&self, point: Point) -> f32 {
+        let dx = (self.low.x - point.x).max(0.).max(point.x - self.high.x);
+        let dy = (self.low.y - point.y).max(0.).max(point.y - self.high.y);
+        let dz = (self.low.z - point.z).max(0.).max(point.z - self.high.z);
+        dx * dx + dy * dy + dz * dz
+    }
+}
+
+/// Display implementation for [`AABB`].
+///
+/// [`AABB`]: struct.AABB.html
+///
+/// # Examples
+/// ```
+/// # use beevee::Point;
+/// # use beevee::aabb::AABB;
+/// let low = Point::new(0., 0., 0.);
+/// let high = Point::new(1., 1., 1.);
+/// let aabb = AABB::with_bounds(low, high);
+///
+/// assert_eq!(format!("{}", aabb), "low: {0, 0, 0}, high: {1, 1, 1}");
+/// ```
+impl Display for AABB {
+    fn fmt(&self, f: &mut Formatter) -> Result {
+        write!(f, "low: {}, high: {}", self.low, self.high)
+    }
+}
+
+/// Return an empty [`AABB`].
+///
+/// [`AABB`]: struct.AABB.html
+///
+/// # Examples
+///
+/// ```
+/// # use beevee::aabb::AABB;
+/// let default = <AABB as Default>::default();
+/// let empty = AABB::empty();
+///
+/// assert_eq!(default, empty);
+/// ```
+impl Default for AABB {
+    fn default() -> Self {
+        AABB::empty()
+    }
+}

beevee/src/aabb/mod.rs

@@ -0,0 +1,7 @@
+//! The module relating to Axis-Aligned Bounding Boxes.
+
+mod bounded;
+pub use bounded::*;
+
+mod bounding_box;
+pub use bounding_box::*;

beevee/src/axis.rs

@@ -0,0 +1,170 @@
+use crate::{Point, Vector};
+use std::fmt::{Display, Formatter, Result};
+use std::ops::{Index, IndexMut};
+
+/// An enum for indexing different spatial structures.
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+pub enum Axis {
+    /// The X axis.
+    X = 0,
+    /// The Y axis.
+    Y = 1,
+    /// The Z axis.
+    Z = 2,
+}
+
+/// Display implementation for [`Axis`].
+///
+/// [`Axis`]: enum.Axis.html
+///
+/// # Examples
+/// ```
+/// # use beevee::Axis;
+/// assert_eq!(format!("{}", Axis::X), "x");
+/// assert_eq!(format!("{}", Axis::Y), "y");
+/// assert_eq!(format!("{}", Axis::Z), "z");
+/// ```
+impl Display for Axis {
+    fn fmt(&self, f: &mut Formatter) -> Result {
+        write!(
+            f,
+            "{}",
+            match *self {
+                Axis::X => "x",
+                Axis::Y => "y",
+                Axis::Z => "z",
+            }
+        )
+    }
+}
+
+/// Slice indexing implementation by [`Axis`]
+///
+/// [`Axis`]: enum.Axis.html
+///
+/// # Examples
+/// ```
+/// # use beevee::Axis;
+/// #
+/// let slice = &[0., 1., 2.];
+/// assert_eq!(slice[Axis::X], 0.);
+/// ```
+impl<T> Index<Axis> for [T] {
+    type Output = T;
+
+    fn index(&self, axis: Axis) -> &Self::Output {
+        &self[axis as usize]
+    }
+}
+
+/// Mutable slice indexing implementation by [`Axis`]
+///
+/// [`Axis`]: enum.Axis.html
+///
+/// # Examples
+/// ```
+/// # use beevee::Axis;
+/// #
+/// let slice = &mut [0., 1., 2.];
+/// slice[Axis::X] = 3.;
+/// assert_eq!(slice, &[3., 1., 2.]);
+/// ```
+impl<T> IndexMut<Axis> for [T] {
+    fn index_mut(&mut self, axis: Axis) -> &mut T {
+        &mut self[axis as usize]
+    }
+}
+
+/// [`Point`] indexing implementation by [`Axis`]
+///
+/// [`Axis`]: enum.Axis.html
+/// [`Point`]: type.Point.html
+///
+/// # Examples
+/// ```
+/// # use beevee::{Axis, Point};
+/// #
+/// let point = Point::new(0., 1., 2.);
+/// assert_eq!(point[Axis::X], 0.);
+/// ```
+impl Index<Axis> for Point {
+    type Output = f32;
+
+    fn index(&self, axis: Axis) -> &Self::Output {
+        match axis {
+            Axis::X => &self.x,
+            Axis::Y => &self.y,
+            Axis::Z => &self.z,
+        }
+    }
+}
+
+/// Mutable [`Point`] indexing implementation by [`Axis`]
+///
+/// [`Axis`]: enum.Axis.html
+/// [`Point`]: type.Point.html
+///
+/// # Examples
+/// ```
+/// # use beevee::{Axis, Point};
+/// #
+/// let mut point =  Point::new(0., 1., 2.);
+/// point[Axis::X] = 3.;
+/// assert_eq!(point, Point::new(3., 1., 2.));
+/// ```
+impl IndexMut<Axis> for Point {
+    fn index_mut(&mut self, axis: Axis) -> &mut f32 {
+        match axis {
+            Axis::X => &mut self.x,
+            Axis::Y => &mut self.y,
+            Axis::Z => &mut self.z,
+        }
+    }
+}
+
+/// [`Vector`] indexing implementation by [`Axis`]
+///
+/// [`Axis`]: enum.Axis.html
+/// [`Vector`]: type.Vector.html
+///
+/// # Examples
+/// ```
+/// # use beevee::{Axis, Vector};
+/// #
+/// let point = Vector::new(0., 1., 2.);
+/// assert_eq!(point[Axis::X], 0.);
+/// ```
+impl Index<Axis> for Vector {
+    type Output = f32;
+
+    fn index(&self, axis: Axis) -> &Self::Output {
+        match axis {
+            Axis::X => &self.x,
+            Axis::Y => &self.y,
+            Axis::Z => &self.z,
+        }
+    }
+}
+
+/// Mutable [`Vector`] indexing implementation by [`Axis`]
+///
+/// [`Axis`]: enum.Axis.html
+/// [`Vector`]: type.Vector.html
+///
+/// # Examples
+/// ```
+/// # use beevee::{Axis, Vector};
+/// #
+/// let mut point =  Vector::new(0., 1., 2.);
+/// point[Axis::X] = 3.;
+/// assert_eq!(point, Vector::new(3., 1., 2.));
+/// ```
+impl IndexMut<Axis> for Vector {
+    fn index_mut(&mut self, axis: Axis) -> &mut f32 {
+        match axis {
+            Axis::X => &mut self.x,
+            Axis::Y => &mut self.y,
+            Axis::Z => &mut self.z,
+        }
+    }
+}

beevee/src/bvh/intersected.rs

@@ -0,0 +1,11 @@
+use crate::aabb::Bounded;
+use crate::ray::Ray;
+
+/// The trait for any object to be used in the [`BVH`].
+///
+/// [`BVH`]: struct.BVH.html
+pub trait Intersected: Bounded {
+    /// Return None if there is no intersection, or the distance along the ray to the closest
+    /// intersection
+    fn intersect(&self, ray: &Ray) -> Option<f32>;
+}

beevee/src/bvh/mod.rs

@@ -0,0 +1,7 @@
+//! The Boudning Volume Hiearchy
+
+mod intersected;
+pub use intersected::*;
+
+mod tree;
+pub use tree::*;

beevee/src/bvh/tree.rs

@@ -0,0 +1,495 @@
+use super::Intersected;
+use crate::aabb::AABB;
+use crate::ray::Ray;
+use crate::Axis;
+
+/// An enum representing either an internal or a leaf node of the [`BVH`]
+///
+/// [`BVH`]: struct.BVH.html
+#[derive(Clone, Debug, PartialEq)]
+enum NodeEnum {
+    Internal { left: Box<Node>, right: Box<Node> },
+    Leaf,
+}
+
+/// A node representing either an internal or a leaf node of the [`BVH`]
+///
+#[derive(Clone, Debug, PartialEq)]
+struct Node {
+    bounds: AABB,
+    begin: usize,
+    end: usize,
+    kind: NodeEnum,
+}
+
+/// The BVH containing all the objects of type O.
+/// This type must implement [`Intersected`].
+///
+/// [`Intersected`]: trait.Intersected.html
+#[derive(Clone, Debug, PartialEq)]
+pub struct BVH {
+    tree: Node,
+}
+
+impl BVH {
+    /// Build a [`BVH`] for the given slice of objects.
+    /// Each leaf node will be built in a way to try and contain less than 32 objects.
+    ///
+    /// # Examples
+    /// ```
+    /// use beevee::{Point, Vector};
+    /// use beevee::aabb::{AABB, Bounded};
+    /// use beevee::bvh::{BVH, Intersected};
+    /// use beevee::ray::Ray;
+    ///
+    /// #[derive(Clone, Debug, PartialEq)]
+    /// struct Sphere {
+    ///     center: Point,
+    ///     radius: f32,
+    /// }
+    ///
+    /// impl Bounded for Sphere {
+    ///     fn aabb(&self) -> AABB {
+    ///         let delt = Vector::new(self.radius, self.radius, self.radius);
+    ///         AABB::with_bounds(self.center - delt, self.center + delt)
+    ///     }
+    ///     fn centroid(&self) -> Point {
+    ///         self.center
+    ///     }
+    /// }
+    ///
+    /// impl Intersected for Sphere {
+    ///     fn intersect(&self, ray: &Ray) -> Option<f32> {
+    ///         use std::mem;
+    ///
+    ///         let delt = self.center - ray.origin;
+    ///         let tca = ray.direction.dot(&delt);
+    ///         let d2 = delt.norm_squared() - tca * tca;
+    ///         let r_2 = self.radius * self.radius;
+    ///
+    ///         if d2 > r_2 {
+    ///             return None;
+    ///         }
+    ///
+    ///         let thc = (r_2 - d2).sqrt();
+    ///         let mut t_0 = tca - thc;
+    ///         let mut t_1 = tca + thc;
+    ///
+    ///         if t_0 > t_1 {
+    ///             mem::swap(&mut t_0, &mut t_1)
+    ///         }
+    ///         if t_0 < 0. {
+    ///             t_0 = t_1
+    ///         }
+    ///         if t_0 < 0. {
+    ///             None
+    ///         } else {
+    ///             Some(t_0)
+    ///         }
+    ///     }
+    /// }
+    ///
+    /// let spheres: &mut [Sphere] = &mut [Sphere{ center: Point::origin(), radius: 2.5 }];
+    /// let bvh = BVH::build(spheres);
+    /// ```
+    pub fn build<O: Intersected>(objects: &mut [O]) -> Self {
+        Self::with_max_capacity(objects, 32)
+    }
+
+    /// Build a [`BVH`] for the given slice of objects, with an indicated max capacity per
+    /// leaf-node. The max capacity is not respected when the SAH heuristic indicate that it would
+    /// be better to iterate over all objects instead of splitting.
+    ///
+    /// # Examples
+    /// ```
+    /// use beevee::{Point, Vector};
+    /// use beevee::aabb::{AABB, Bounded};
+    /// use beevee::bvh::{BVH, Intersected};
+    /// use beevee::ray::Ray;
+    ///
+    /// #[derive(Clone, Debug, PartialEq)]
+    /// struct Sphere {
+    ///     center: Point,
+    ///     radius: f32,
+    /// }
+    ///
+    /// impl Bounded for Sphere {
+    ///     fn aabb(&self) -> AABB {
+    ///         let delt = Vector::new(self.radius, self.radius, self.radius);
+    ///         AABB::with_bounds(self.center - delt, self.center + delt)
+    ///     }
+    ///     fn centroid(&self) -> Point {
+    ///         self.center
+    ///     }
+    /// }
+    ///
+    /// impl Intersected for Sphere {
+    ///     fn intersect(&self, ray: &Ray) -> Option<f32> {
+    ///         use std::mem;
+    ///
+    ///         let delt = self.center - ray.origin;
+    ///         let tca = ray.direction.dot(&delt);
+    ///         let d2 = delt.norm_squared() - tca * tca;
+    ///         let r_2 = self.radius * self.radius;
+    ///
+    ///         if d2 > r_2 {
+    ///             return None;
+    ///         }
+    ///
+    ///         let thc = (r_2 - d2).sqrt();
+    ///         let mut t_0 = tca - thc;
+    ///         let mut t_1 = tca + thc;
+    ///
+    ///         if t_0 > t_1 {
+    ///             mem::swap(&mut t_0, &mut t_1)
+    ///         }
+    ///         if t_0 < 0. {
+    ///             t_0 = t_1
+    ///         }
+    ///         if t_0 < 0. {
+    ///             None
+    ///         } else {
+    ///             Some(t_0)
+    ///         }
+    ///     }
+    /// }
+    ///
+    /// let spheres: &mut [Sphere] = &mut [Sphere{ center: Point::origin(), radius: 2.5 }];
+    /// let bvh = BVH::with_max_capacity(spheres, 32);
+    /// ```
+    pub fn with_max_capacity<O: Intersected>(objects: &mut [O], max_cap: usize) -> Self {
+        let tree = build_node(objects, 0, objects.len(), max_cap);
+        Self { tree }
+    }
+
+    /// Return the true if the [`BVH`] has been built soundly:
+    /// * Each child node is contained inside the parent's bounding box.
+    /// * Each object in a leaf node is inside the node's bounding box.
+    /// * There is no missing object indices.
+    ///
+    /// # Examples
+    /// ```
+    /// # use beevee::{Point, Vector};
+    /// # use beevee::aabb::{AABB, Bounded};
+    /// # use beevee::bvh::{BVH, Intersected};
+    /// # use beevee::ray::Ray;
+    /// #
+    /// # #[derive(Clone, Debug, PartialEq)]
+    /// # struct Sphere {
+    /// #     center: Point,
+    /// #     radius: f32,
+    /// # }
+    /// #
+    /// # impl Bounded for Sphere {
+    /// #     fn aabb(&self) -> AABB {
+    /// #         let delt = Vector::new(self.radius, self.radius, self.radius);
+    /// #         AABB::with_bounds(self.center - delt, self.center + delt)
+    /// #     }
+    /// #     fn centroid(&self) -> Point {
+    /// #         self.center
+    /// #     }
+    /// # }
+    /// #
+    /// # impl Intersected for Sphere {
+    /// #     fn intersect(&self, ray: &Ray) -> Option<f32> {
+    /// #         use std::mem;
+    /// #
+    /// #         let delt = self.center - ray.origin;
+    /// #         let tca = ray.direction.dot(&delt);
+    /// #         let d2 = delt.norm_squared() - tca * tca;
+    /// #         let r_2 = self.radius * self.radius;
+    /// #
+    /// #         if d2 > r_2 {
+    /// #             return None;
+    /// #         }
+    /// #
+    /// #         let thc = (r_2 - d2).sqrt();
+    /// #         let mut t_0 = tca - thc;
+    /// #         let mut t_1 = tca + thc;
+    /// #
+    /// #         if t_0 > t_1 {
+    /// #             mem::swap(&mut t_0, &mut t_1)
+    /// #         }
+    /// #         if t_0 < 0. {
+    /// #             t_0 = t_1
+    /// #         }
+    /// #         if t_0 < 0. {
+    /// #             None
+    /// #         } else {
+    /// #             Some(t_0)
+    /// #         }
+    /// #     }
+    /// # }
+    /// #
+    /// // Using the same sphere definition than build
+    /// let spheres: &mut [Sphere] = &mut [Sphere{ center: Point::origin(), radius: 2.5 }];
+    /// let bvh = BVH::with_max_capacity(spheres, 32);
+    /// assert!(bvh.is_sound(spheres));
+    /// ```
+    pub fn is_sound<O: Intersected>(&self, objects: &[O]) -> bool {
+        fn check_node<O: Intersected>(objects: &[O], node: &Node) -> bool {
+            if node.begin > node.end {
+                return false;
+            }
+            match node.kind {
+                NodeEnum::Leaf => objects[node.begin..node.end]
+                    .iter()
+                    .all(|o| node.bounds.union(&o.aabb()) == node.bounds),
+                NodeEnum::Internal {
+                    ref left,
+                    ref right,
+                } => {
+                    check_node(objects, left.as_ref())
+                        && check_node(objects, right.as_ref())
+                        && node.bounds.union(&left.bounds) == node.bounds
+                        && node.bounds.union(&right.bounds) == node.bounds
+                }
+            }
+        };
+        check_node(objects, &self.tree)
+    }
+
+    /// Iterate recursively over the [`BVH`] to find an intersection point with the given [`Ray`].
+    /// This algorithm tries to only iterate over Nodes that are abolutely necessary, and skip
+    /// visiting nodes that are too far away.
+    ///
+    /// [`BVH`]: struct.BVH.html
+    /// [`Ray`]: ../ray/struct.Ray.html
+    /// # Examples
+    /// ```
+    /// # use beevee::{Point, Vector};
+    /// # use beevee::aabb::{AABB, Bounded};
+    /// # use beevee::bvh::{BVH, Intersected};
+    /// # use beevee::ray::Ray;
+    /// #
+    /// # #[derive(Clone, Debug, PartialEq)]
+    /// # struct Sphere {
+    /// #     center: Point,
+    /// #     radius: f32,
+    /// # }
+    /// #
+    /// # impl Bounded for Sphere {
+    /// #     fn aabb(&self) -> AABB {
+    /// #         let delt = Vector::new(self.radius, self.radius, self.radius);
+    /// #         AABB::with_bounds(self.center - delt, self.center + delt)
+    /// #     }
+    /// #     fn centroid(&self) -> Point {
+    /// #         self.center
+    /// #     }
+    /// # }
+    /// #
+    /// # impl Intersected for Sphere {
+    /// #     fn intersect(&self, ray: &Ray) -> Option<f32> {
+    /// #         use std::mem;
+    /// #
+    /// #         let delt = self.center - ray.origin;
+    /// #         let tca = ray.direction.dot(&delt);
+    /// #         let d2 = delt.norm_squared() - tca * tca;
+    /// #         let r_2 = self.radius * self.radius;
+    /// #
+    /// #         if d2 > r_2 {
+    /// #             return None;
+    /// #         }
+    /// #
+    /// #         let thc = (r_2 - d2).sqrt();
+    /// #         let mut t_0 = tca - thc;
+    /// #         let mut t_1 = tca + thc;
+    /// #
+    /// #         if t_0 > t_1 {
+    /// #             mem::swap(&mut t_0, &mut t_1)
+    /// #         }
+    /// #         if t_0 < 0. {
+    /// #             t_0 = t_1
+    /// #         }
+    /// #         if t_0 < 0. {
+    /// #             None
+    /// #         } else {
+    /// #             Some(t_0)
+    /// #         }
+    /// #     }
+    /// # }
+    /// #
+    /// // Using the same sphere definition than build
+    /// let spheres: &mut [Sphere] = &mut [Sphere{ center: Point::origin(), radius: 0.5 }];
+    /// let bvh = BVH::with_max_capacity(spheres, 32);
+    ///
+    /// // This ray is directly looking at the spheres
+    /// let ray = Ray::new(Point::new(-1., 0., 0.), Vector::x_axis());
+    /// let res = bvh.walk(&ray, spheres);
+    ///
+    /// assert!(res.is_some());
+    /// let (dist, obj) = res.unwrap();
+    /// assert_eq!(dist, 0.5);
+    /// assert_eq!(obj, &spheres[0]);
+    /// ```
+    pub fn walk<'o, O: Intersected>(&self, ray: &Ray, objects: &'o [O]) -> Option<(f32, &'o O)> {
+        walk_rec_helper(ray, objects, &self.tree, std::f32::INFINITY)
+    }
+}
+
+fn walk_rec_helper<'o, O: Intersected>(
+    ray: &Ray,
+    objects: &'o [O],
+    node: &Node,
+    min: f32,
+) -> Option<(f32, &'o O)> {
+    use std::cmp::Ordering;
+
+    match &node.kind {
+        // Return the smallest intersection distance on leaf nodes
+        NodeEnum::Leaf => objects[node.begin..node.end]
+            .iter()
+            // This turns the Option<f32> of an intersection into an Option<(f32, &O)>
+            .filter_map(|o| o.intersect(ray).map(|d| (d, o)))
+            // Discard values that are too far away
+            .filter(|(dist, _)| dist < &min)
+            // Only keep the minimum value, if there is one
+            .min_by(|(lhs, _), (rhs, _)| lhs.partial_cmp(rhs).unwrap_or(Ordering::Equal)),
+
+        // Recursively find the best node otherwise
+        NodeEnum::Internal { left, right } => {
+            let left_dist = left.bounds.distance_to_point(ray.origin);
+            let right_dist = right.bounds.distance_to_point(ray.origin);
+            // Pick the short and far nodes
+            let (near, far, short_dist, far_dist) = if left_dist < right_dist {
+                (left, right, left_dist, right_dist)
+            } else {
+                (right, left, right_dist, left_dist)
+            };
+            // Don't recurse if we know we cannot possibly find a short-enough intersection
+            if short_dist > min {
+                return None;
+            }
+            // Recurse to the nearest Node first
+            let nearest_res = walk_rec_helper(ray, objects, near.as_ref(), min);
+            // Return immediately if there is no point going to the right at all
+            if far_dist > min {
+                return nearest_res;
+            }
+            match nearest_res {
+                // Short-circuit if we know it is shorter than any point in the far node
+                Some((t, obj)) if t <= far_dist => Some((t, obj)),
+                // We have short_dist <= far_dist <= min in this scenario
+                // With the eventual val.0 in the [short_dist, min) window
+                val => {
+                    // Compute the new minimal distance encountered
+                    let min = val.map_or(min, |(t, _)| min.min(t));
+                    // Recursing with this new minimum can only return None or a better intersecion
+                    walk_rec_helper(ray, objects, far.as_ref(), min).or(val)
+                }
+            }
+        }
+    }
+}
+
+fn bounds_from_slice<O: Intersected>(objects: &[O]) -> AABB {
+    objects
+        .iter()
+        .map(|o| o.aabb())
+        .fold(AABB::empty(), |acc, other| acc.union(&other))
+}
+
+fn build_node<O: Intersected>(objects: &mut [O], begin: usize, end: usize, max_cap: usize) -> Node {
+    let aabb = bounds_from_slice(objects);
+    // Don't split nodes under capacity
+    if objects.len() <= max_cap {
+        return Node {
+            bounds: aabb,
+            begin,
+            end,
+            kind: NodeEnum::Leaf,
+        };
+    }
+    // Calculate the SAH heuristic for this slice
+    let (split, axis, cost) = compute_sah(&mut objects[begin..end], aabb.surface(), max_cap);
+    // Only split if the heuristic shows that it is worth it
+    if cost >= objects.len() as f32 {
+        return Node {
+            bounds: aabb,
+            begin,
+            end,
+            kind: NodeEnum::Leaf,
+        };
+    }
+    // Avoid degenerate cases, and recenter the split inside [begin, end)
+    let split = if split == 0 || split >= (end - begin - 1) {
+        begin + (end - begin) / 2
+    } else {
+        begin + split
+    };
+    // Project along chosen axis
+    pdqselect::select_by(objects, split, |lhs, rhs| {
+        lhs.centroid()[axis]
+            .partial_cmp(&rhs.centroid()[axis])
+            .expect("Can't use Nans in the SAH computation")
+    });
+    // Construct children recurivsely on [begin, split) and [split, end)
+    let left = Box::new(build_node(objects, begin, split, max_cap));
+    let right = Box::new(build_node(objects, split, end, max_cap));
+    // Build the node recursivelly
+    Node {
+        bounds: aabb,
+        begin,
+        end,
+        kind: NodeEnum::Internal { left, right },
+    }
+}
+
+/// Returns the index at which to split for SAH, the Axis along which to split, and the calculated
+/// cost.
+fn compute_sah<O: Intersected>(
+    objects: &mut [O],
+    surface: f32,
+    max_cap: usize,
+) -> (usize, Axis, f32) {
+    // FIXME(Bruno): too imperative to my taste...
+    let mut mid = objects.len() / 2;
+    let mut dim = Axis::X; // Arbitrary split
+    let mut min = std::f32::INFINITY;
+
+    // Pre-allocate the vectors
+    let mut left_surfaces = Vec::<f32>::with_capacity(objects.len() - 1);
+    let mut right_surfaces = Vec::<f32>::with_capacity(objects.len() - 1);
+
+    // For each axis compute the cost
+    for &axis in [Axis::X, Axis::Y, Axis::Z].iter() {
+        left_surfaces.clear();
+        right_surfaces.clear();
+        // Sort in order along the axis
+        objects.sort_by(|lhs, rhs| {
+            lhs.centroid()[axis]
+                .partial_cmp(&rhs.centroid()[axis])
+                .expect("Can't use NaNs in the SAH computation")
+        });
+
+        // Compute the surface for each possible split
+        {
+            let mut left_box = AABB::empty();
+            let mut right_box = AABB::empty();
+            for i in 0..(objects.len() - 1) {
+                left_box.union_mut(&objects[i].aabb());
+                left_surfaces.push(left_box.surface());
+
+                right_box.union_mut(&objects[objects.len() - 1 - i].aabb());
+                right_surfaces.push(right_box.surface());
+            }
+        }
+
+        // Calculate the cost
+        for left_count in 1..objects.len() {
+            let right_count = objects.len() - left_count;
+
+            let cost = 1. / max_cap as f32
+                + (left_count as f32 * left_surfaces[left_count - 1]
+                    + right_count as f32 * right_surfaces[right_count])
+                    / surface;
+
+            if cost < min {
+                min = cost;
+                dim = axis;
+                mid = left_count
+            }
+        }
+    }
+    (mid, dim, min)
+}

beevee/src/lib.rs

@@ -0,0 +1,28 @@
+#![warn(missing_docs)]
+
+//! A Bounding Volume Hierarchy crate for use with ray-tracing.
+
+/// The point to describe the [`AABB`]'s corners.
+///
+/// [`AABB`]: aabb/struct.AABB.html
+pub type Point = nalgebra::Point3<f32>;
+
+/// The Vector to describe the [`Ray`]'s direction.
+///
+/// [`Ray`]: ray/struct.Ray.html
+pub type Vector = nalgebra::Vector3<f32>;
+
+/// The module relating to Axis-Aligned Bouding Boxes.
+pub mod aabb;
+
+mod axis;
+pub use axis::*;
+
+/// The module relating to Bouding Volume Hiearchy
+pub mod bvh;
+
+/// Module defining a [`Ray`] structure to intersect with the [`BVH`]
+///
+/// [`BVH`]: ../bvh/struct.BVH.html
+/// [`Ray`]: ray/struct.Ray.html
+pub mod ray;

beevee/src/ray.rs

@@ -0,0 +1,152 @@
+use crate::aabb::AABB;
+use crate::{Point, Vector};
+use nalgebra::Unit;
+use std::fmt::{Display, Formatter, Result};
+
+/// The [`Ray`] to intersect with the [`BVH`].
+///
+/// [`BVH`]: ../bvh/struct.BVH.html
+/// [`Ray`]: struct.Ray.html
+#[derive(Copy, Clone, Debug, PartialEq)]
+pub struct Ray {
+    /// The point of origin of the ray.
+    pub origin: Point,
+    /// A unit vector representing the direction of the ray.
+    pub direction: Unit<Vector>,
+    /// The inverse of each coefficient of the ray's direction.
+    pub inv_direction: Vector,
+}
+
+impl Ray {
+    /// Create a new [`Ray`] with the given origin and direction
+    ///
+    /// [`Ray`]: struct.Ray.html
+    ///
+    /// # Examples
+    /// ```
+    /// use beevee::{Point, Vector};
+    /// use beevee::ray::Ray;
+    ///
+    /// let ray = Ray::new(Point::origin(), Vector::x_axis());
+    /// ```
+    #[must_use]
+    pub fn new(origin: Point, direction: Unit<Vector>) -> Self {
+        let inv_direction = Vector::new(1. / direction.x, 1. / direction.y, 1. / direction.z);
+        Ray {
+            origin,
+            direction,
+            inv_direction,
+        }
+    }
+
+    /// Return the distance to intersect with an [`AABB`], or [`None`] if there's no intersection.
+    ///
+    /// [`AABB`]: ../aabb/struct.AABB.html
+    /// [`Ray`]: struct.Ray.html
+    ///
+    /// # Examples
+    /// ```
+    /// use beevee::{Point, Vector};
+    /// use beevee::aabb::AABB;
+    /// use beevee::ray::Ray;
+    ///
+    /// let aabb = AABB::with_bounds(Point::new(1., -1., -1.), Point::new(3., 1., 1.));
+    /// let ray = Ray::new(Point::origin(), Vector::x_axis());
+    ///
+    /// assert_eq!(ray.aabb_intersection(&aabb), Some(1.));
+    /// ```
+    ///
+    /// ```
+    /// use beevee::{Point, Vector};
+    /// use beevee::aabb::AABB;
+    /// use beevee::ray::Ray;
+    ///
+    /// let aabb = AABB::with_bounds(Point::new(-1., -1., -1.), Point::new(1., 1., 1.));
+    /// let ray = Ray::new(Point::origin(), Vector::x_axis());
+    ///
+    /// // Also works from inside the AABB.
+    /// assert_eq!(ray.aabb_intersection(&aabb), Some(1.));
+    /// ```
+    ///
+    /// ```
+    /// use beevee::{Point, Vector};
+    /// use beevee::aabb::AABB;
+    /// use beevee::ray::Ray;
+    ///
+    /// let aabb = AABB::with_bounds(Point::new(1., -1., -1.), Point::new(3., 1., 1.));
+    /// let ray = Ray::new(Point::origin(), Vector::y_axis());
+    ///
+    /// assert_eq!(ray.aabb_intersection(&aabb), None);
+    /// ```
+    pub fn aabb_intersection(&self, aabb: &AABB) -> Option<f32> {
+        use crate::Axis;
+        let min_max = |axis: Axis| {
+            let a = (aabb.high[axis] - self.origin[axis]) * self.inv_direction[axis];
+            let b = (aabb.low[axis] - self.origin[axis]) * self.inv_direction[axis];
+            if self.direction[axis] < 0. {
+                (a, b)
+            } else {
+                (b, a)
+            }
+        };
+        let (mut t_min, mut t_max) = min_max(Axis::X);
+
+        let (y_min, y_max) = min_max(Axis::Y);
+
+        if y_min > t_max || y_max < t_min {
+            return None;
+        }
+
+        if y_min > t_min {
+            t_min = y_min;
+        }
+        if y_max < t_max {
+            t_max = y_max;
+        }
+
+        let (z_min, z_max) = min_max(Axis::Z);
+
+        if z_min > t_max || z_max < t_min {
+            return None;
+        }
+
+        if z_min > t_min {
+            t_min = z_min;
+        }
+        if z_max < t_max {
+            t_max = z_max;
+        }
+
+        if t_max < 0. {
+            return None;
+        }
+
+        if t_min < 0. {
+            Some(t_max)
+        } else {
+            Some(t_min)
+        }
+    }
+}
+
+/// Display implementation for [`Ray`].
+///
+/// [`Ray`]: struct.Ray.html
+///
+/// # Examples
+/// ```
+/// # use beevee::{Point, Vector};
+/// # use beevee::ray::Ray;
+/// let ray = Ray::new(Point::origin(), Vector::x_axis());
+///
+/// assert_eq!(format!("{}", ray), "origin: {0, 0, 0}, direction: {1, 0, 0}")
+/// ```
+impl Display for Ray {
+    fn fmt(&self, f: &mut Formatter) -> Result {
+        write!(
+            f,
+            "origin: {}, direction: {{{}, {}, {}}}",
+            self.origin, self.direction.x, self.direction.y, self.direction.z,
+        )
+    }
+}

pathtracer/Cargo.toml

@@ -0,0 +1,38 @@
+[package]
+name = "pathtracer"
+version = "0.1.0"
+authors = [
+    "Bruno BELANYI <brunobelanyi@gmail.com>",
+    "Antoine Martin <antoine97.martin@gmail.com>"
+]
+edition = "2018"
+description = "A pathtracer written in Rust"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[lib]
+name = "pathtracer"
+path = "src/lib.rs"
+
+[[bin]]
+name = "pathtracer"
+path = "src/main.rs"
+
+[dependencies]
+beevee = { path = "../beevee" }
+derive_more = "0.99.3"
+enum_dispatch = "0.2.1"
+image = "0.23.0"
+indicatif = "0.14.0"
+rand = "0.7"
+rayon = "1.3.0"
+serde_yaml = "0.8"
+structopt = "0.3"
+
+[dependencies.nalgebra]
+version = "0.20.0"
+features = ["serde-serialize"]
+
+[dependencies.serde]
+version = "1.0"
+features = ["derive"]

pathtracer/src/lib.rs

@@ -2,14 +2,11 @@
 
 //! A pathtracing crate
 
-use bvh::nalgebra::{Point2, Point3, Vector3};
+/// 3D points and vectors
+pub use beevee::{Point, Vector};
 
 /// A 2D point coordinate
-pub type Point2D = Point2<f32>;
+pub type Point2D = nalgebra::Point2<f32>;
-/// A 3D point coordinate
-pub type Point = Point3<f32>;
-/// A 3D vector
-pub type Vector = Vector3<f32>;
 
 pub mod core;
 pub mod light;

pathtracer/src/light/directional_light.rs

@@ -1,13 +1,14 @@
 use super::{Light, SpatialLight};
 use crate::core::LinearColor;
 use crate::{Point, Vector};
+use nalgebra::Unit;
 use serde::Deserialize;
 
 /// Represent a light emanating from a far away source, with parallel rays on all points.
 #[derive(Debug, PartialEq, Deserialize)]
 pub struct DirectionalLight {
     #[serde(deserialize_with = "crate::serialize::vector_normalizer")]
-    direction: Vector,
+    direction: Unit<Vector>,
     color: LinearColor,
 }
 
@@ -22,15 +23,12 @@ impl DirectionalLight {
     /// # use pathtracer::Vector;
     /// #
     /// let dir_light = DirectionalLight::new(
-    ///     Vector::new(1.0, 0.0, 0.0),
+    ///     Vector::x_axis(),
     ///     LinearColor::new(1.0, 0.0, 1.0),
     /// );
     /// ```
-    pub fn new(direction: Vector, color: LinearColor) -> Self {
+    pub fn new(direction: Unit<Vector>, color: LinearColor) -> Self {
-        DirectionalLight {
+        DirectionalLight { direction, color }
-            direction: direction.normalize(),
-            color,
-        }
     }
 }
 
@@ -41,8 +39,8 @@ impl Light for DirectionalLight {
 }
 
 impl SpatialLight for DirectionalLight {
-    fn to_source(&self, _: &Point) -> (Vector, f32) {
+    fn to_source(&self, _: &Point) -> (Unit<Vector>, f32) {
-        (self.direction * -1., std::f32::INFINITY)
+        (-self.direction, std::f32::INFINITY)
     }
 }
 
@@ -52,7 +50,7 @@ mod test {
 
     #[test]
     fn new_works() {
-        let direction = Vector::new(1., 0., 0.);
+        let direction = Vector::x_axis();
         let color = LinearColor::new(1., 1., 1.);
         let light = DirectionalLight::new(direction, color.clone());
         let res = DirectionalLight { direction, color };
@@ -60,7 +58,7 @@ mod test {
     }
 
     fn simple_light() -> impl SpatialLight {
-        let direction = Vector::new(1., 0., 0.);
+        let direction = Vector::x_axis();
         let color = LinearColor::new(1., 1., 1.);
         DirectionalLight::new(direction, color)
     }
@@ -76,7 +74,10 @@ mod test {
     fn to_source_is_correct() {
         let light = simple_light();
         let ans = light.to_source(&Point::new(1., 0., 0.));
-        let expected = (Vector::new(-1., 0., 0.), std::f32::INFINITY);
+        let expected = (
+            Unit::new_normalize(Vector::new(-1., 0., 0.)),
+            std::f32::INFINITY,
+        );
         assert_eq!(ans, expected)
     }
 
@@ -86,7 +87,7 @@ mod test {
         let light: DirectionalLight = serde_yaml::from_str(yaml).unwrap();
         assert_eq!(
             light,
-            DirectionalLight::new(Vector::new(1., 0., 0.), LinearColor::new(1., 0.5, 0.2))
+            DirectionalLight::new(Vector::x_axis(), LinearColor::new(1., 0.5, 0.2))
         )
     }
 }

pathtracer/src/light/mod.rs

@@ -2,6 +2,7 @@
 
 use super::core::LinearColor;
 use super::{Point, Vector};
+use nalgebra::Unit;
 
 /// Represent a light in the scene being rendered.
 pub trait Light: std::fmt::Debug {
@@ -12,7 +13,7 @@ pub trait Light: std::fmt::Debug {
 /// Represent a light which has an abstract position in the scene being rendered.
 pub trait SpatialLight: Light {
     /// Get a unit vector from the origin to the position of the light, and its distance
-    fn to_source(&self, origin: &Point) -> (Vector, f32);
+    fn to_source(&self, origin: &Point) -> (Unit<Vector>, f32);
 }
 
 mod ambient_light;

pathtracer/src/light/point_light.rs

@@ -1,6 +1,7 @@
 use super::{Light, SpatialLight};
 use crate::core::LinearColor;
 use crate::{Point, Vector};
+use nalgebra::Unit;
 use serde::Deserialize;
 
 /// Represent a light emanating from a point in space, following the square distance law.
@@ -38,10 +39,10 @@ impl Light for PointLight {
 }
 
 impl SpatialLight for PointLight {
-    fn to_source(&self, point: &Point) -> (Vector, f32) {
+    fn to_source(&self, point: &Point) -> (Unit<Vector>, f32) {
         let delt = self.position - point;
         let dist = delt.norm();
-        (delt.normalize(), dist)
+        (Unit::new_normalize(delt), dist)
     }
 }
 
@@ -75,7 +76,7 @@ mod test {
     fn to_source_is_correct() {
         let light = simple_light();
         let ans = light.to_source(&Point::new(1., 0., 0.));
-        let expected = (Vector::new(-1., 0., 0.), 1.);
+        let expected = (Unit::new_normalize(Vector::new(-1., 0., 0.)), 1.);
         assert_eq!(ans, expected);
     }
 

pathtracer/src/light/spot_light.rs

@@ -1,6 +1,7 @@
 use super::{Light, SpatialLight};
 use crate::core::LinearColor;
 use crate::{Point, Vector};
+use nalgebra::Unit;
 use serde::{Deserialize, Deserializer};
 
 /// Represent a light emanating from a directed light-source, outputting rays in a cone.
@@ -9,7 +10,7 @@ use serde::{Deserialize, Deserializer};
 #[derive(Debug, PartialEq)]
 pub struct SpotLight {
     position: Point,
-    direction: Vector,
+    direction: Unit<Vector>,
     cosine_value: f32,
     color: LinearColor,
 }
@@ -18,13 +19,13 @@ impl SpotLight {
     /// Construct a SpotLight with the given FOV in radian.
     pub fn radians_new(
         position: Point,
-        direction: Vector,
+        direction: Unit<Vector>,
         fov_rad: f32,
         color: LinearColor,
     ) -> Self {
         SpotLight {
             position,
-            direction: direction.normalize(),
+            direction,
             cosine_value: (fov_rad / 2.).cos(),
             color,
         }
@@ -33,7 +34,7 @@ impl SpotLight {
     /// Construct a SpotLight with the given FOV in degrees.
     pub fn degrees_new(
         position: Point,
-        direction: Vector,
+        direction: Unit<Vector>,
         fov_deg: f32,
         color: LinearColor,
     ) -> Self {
@@ -59,10 +60,10 @@ impl Light for SpotLight {
 }
 
 impl SpatialLight for SpotLight {
-    fn to_source(&self, point: &Point) -> (Vector, f32) {
+    fn to_source(&self, point: &Point) -> (Unit<Vector>, f32) {
         let delt = self.position - point;
         let dist = delt.norm();
-        (delt.normalize(), dist)
+        (Unit::new_normalize(delt), dist)
     }
 }
 
@@ -70,7 +71,7 @@ impl SpatialLight for SpotLight {
 struct SerializedSpotLight {
     position: Point,
     #[serde(deserialize_with = "crate::serialize::vector_normalizer")]
-    direction: Vector,
+    direction: Unit<Vector>,
     fov: f32,
     color: LinearColor,
 }
@@ -99,7 +100,7 @@ mod test {
     fn radian_new_works() {
         let light = SpotLight::radians_new(
             Point::origin(),
-            Vector::new(1., 0., 0.),
+            Vector::x_axis(),
             std::f32::consts::PI / 2.,
             LinearColor::new(1., 1., 1.),
         );
@@ -109,7 +110,7 @@ mod test {
             light,
             SpotLight {
                 position: Point::origin(),
-                direction: Vector::new(1., 0., 0.),
+                direction: Vector::x_axis(),
                 cosine_value: calculated_cosine_value,
                 color: LinearColor::new(1., 1., 1.),
             }
@@ -122,7 +123,7 @@ mod test {
     fn degrees_new_works() {
         let light = SpotLight::degrees_new(
             Point::origin(),
-            Vector::new(1., 0., 0.),
+            Vector::x_axis(),
             60.,
             LinearColor::new(1., 1., 1.),
         );
@@ -131,7 +132,7 @@ mod test {
             light,
             SpotLight {
                 position: Point::origin(),
-                direction: Vector::new(1., 0., 0.),
+                direction: Vector::x_axis(),
                 cosine_value: calculated_cosine_value,
                 color: LinearColor::new(1., 1., 1.),
             }
@@ -143,7 +144,7 @@ mod test {
     fn simple_light() -> impl SpatialLight {
         SpotLight::degrees_new(
             Point::origin(),
-            Vector::new(1., 0., 0.),
+            Vector::x_axis(),
             90.,
             LinearColor::new(1., 1., 1.),
         )
@@ -181,7 +182,7 @@ mod test {
     fn to_source_is_correct() {
         let light = simple_light();
         let ans = light.to_source(&Point::new(1., 0., 0.));
-        let expected = (Vector::new(-1., 0., 0.), 1.);
+        let expected = (Unit::new_normalize(Vector::new(-1., 0., 0.)), 1.);
         assert_eq!(ans, expected);
     }
 
@@ -198,7 +199,7 @@ mod test {
             light,
             SpotLight::degrees_new(
                 Point::origin(),
-                Vector::new(1., 0., 0.),
+                Vector::x_axis(),
                 90.,
                 LinearColor::new(1., 0.5, 0.2)
             )

pathtracer/src/render/light_aggregate.rs

@@ -141,7 +141,7 @@ mod test {
         let expected = LightAggregate::new(
             vec![AmbientLight::new(LinearColor::new(1., 0.5, 0.2))],
             vec![DirectionalLight::new(
-                Vector::new(1., 0., 0.),
+                Vector::x_axis(),
                 LinearColor::new(1., 0.5, 0.2),
             )],
             vec![PointLight::new(
@@ -150,7 +150,7 @@ mod test {
             )],
             vec![SpotLight::degrees_new(
                 Point::origin(),
-                Vector::new(1., 0., 0.),
+                Vector::x_axis(),
                 90.,
                 LinearColor::new(1., 0.5, 0.2),
             )],

pathtracer/src/render/object.rs

@@ -3,8 +3,12 @@
 use crate::material::MaterialEnum;
 use crate::shape::{Shape, ShapeEnum};
 use crate::texture::TextureEnum;
-use bvh::aabb::{Bounded, AABB};
+use crate::Point;
-use bvh::bounding_hierarchy::BHShape;
+use beevee::{
+    aabb::{Bounded, AABB},
+    bvh::Intersected,
+    ray::Ray,
+};
 use serde::Deserialize;
 
 /// An object being rendered in the scene.
@@ -60,14 +64,15 @@ impl Bounded for Object {
     fn aabb(&self) -> AABB {
         self.shape.aabb()
     }
-}
-impl BHShape for Object {
-    fn set_bh_node_index(&mut self, index: usize) {
-        self.index = index
-    }
 
-    fn bh_node_index(&self) -> usize {
+    fn centroid(&self) -> Point {
-        self.index
+        self.shape.centroid()
+    }
+}
+
+impl Intersected for Object {
+    fn intersect(&self, ray: &Ray) -> Option<f32> {
+        self.shape.intersect(ray)
     }
 }
 
@@ -79,7 +84,6 @@ mod test {
     use crate::material::UniformMaterial;
     use crate::shape::Sphere;
     use crate::texture::UniformTexture;
-    use crate::Point;
 
     fn simple_object() -> Object {
         let shape = Sphere::new(Point::new(5., 0., 0.), 1.);

pathtracer/src/render/scene.rs

@@ -1,7 +1,5 @@
 //! Scene rendering logic
 
-use std::cmp::Ordering;
-
 use super::{light_aggregate::LightAggregate, object::Object, utils::*};
 use crate::{
     core::{Camera, LightProperties, LinearColor, ReflTransEnum},
@@ -10,8 +8,9 @@ use crate::{
     texture::Texture,
     {Point, Vector},
 };
-use bvh::{bvh::BVH, ray::Ray};
+use beevee::{bvh::BVH, ray::Ray};
 use image::RgbImage;
+use nalgebra::Unit;
 use rand::prelude::thread_rng;
 use rand::Rng;
 use serde::{Deserialize, Deserializer};
@@ -120,12 +119,12 @@ impl Scene {
     fn pixel(&self, x: f32, y: f32) -> LinearColor {
         let (x, y) = self.camera.film().pixel_ratio(x, y);
         let pixel = self.camera.film().pixel_at_ratio(x, y);
-        let direction = (pixel - self.camera.origin()).normalize();
+        let direction = Unit::new_normalize(pixel - self.camera.origin());
         let indices = RefractionInfo::with_index(self.diffraction_index);
         self.cast_ray(Ray::new(pixel, direction))
             .map_or_else(LinearColor::black, |(t, obj)| {
                 self.color_at(
-                    pixel + direction * t,
+                    pixel + direction.as_ref() * t,
                     obj,
                     direction,
                     self.reflection_limit,
@@ -150,20 +149,14 @@ impl Scene {
     }
 
     fn cast_ray(&self, ray: Ray) -> Option<(f32, &Object)> {
-        self.bvh
+        self.bvh.walk(&ray, &self.objects)
-            .traverse(&ray, &self.objects)
-            .iter()
-            .filter_map(|obj| obj.shape.intersect(&ray).map(|distance| (distance, *obj)))
-            .min_by(|(dist_a, _), (dist_b, _)| {
-                dist_a.partial_cmp(dist_b).unwrap_or(Ordering::Equal)
-            })
     }
 
     fn color_at(
         &self,
         point: Point,
         object: &Object,
-        incident_ray: Vector,
+        incident_ray: Unit<Vector>,
         reflection_limit: u32,
         mut indices: RefractionInfo,
     ) -> LinearColor {
@@ -203,14 +196,14 @@ impl Scene {
         &self,
         point: Point,
         transparency: f32,
-        refracted: Vector,
+        refracted: Unit<Vector>,
         reflection_limit: u32,
         indices: RefractionInfo,
     ) -> LinearColor {
         if transparency > 1e-5 && reflection_limit > 0 {
-            let refraction_start = point + refracted * 0.001;
+            let refraction_start = point + refracted.as_ref() * 0.001;
             if let Some((t, obj)) = self.cast_ray(Ray::new(refraction_start, refracted)) {
-                let resulting_position = refraction_start + refracted * t;
+                let resulting_position = refraction_start + refracted.as_ref() * t;
                 let refracted = self.color_at(
                     resulting_position,
                     obj,
@@ -227,14 +220,14 @@ impl Scene {
     fn reflection(
         &self,
         point: Point,
-        reflected: Vector,
+        reflected: Unit<Vector>,
         reflection_limit: u32,
         indices: RefractionInfo,
     ) -> LinearColor {
         if reflection_limit > 0 {
-            let reflection_start = point + reflected * 0.001;
+            let reflection_start = point + reflected.as_ref() * 0.001;
             if let Some((t, obj)) = self.cast_ray(Ray::new(reflection_start, reflected)) {
-                let resulting_position = reflection_start + reflected * t;
+                let resulting_position = reflection_start + reflected.as_ref() * t;
                 let color = self.color_at(
                     resulting_position,
                     obj,
@@ -253,8 +246,8 @@ impl Scene {
         point: Point,
         object_color: LinearColor,
         properties: &LightProperties,
-        normal: Vector,
+        normal: Unit<Vector>,
-        reflected: Vector,
+        reflected: Unit<Vector>,
     ) -> LinearColor {
         let ambient = self.illuminate_ambient(object_color.clone());
         let spatial = self.illuminate_spatial(point, properties, normal, reflected);
@@ -273,14 +266,14 @@ impl Scene {
         &self,
         point: Point,
         properties: &LightProperties,
-        normal: Vector,
+        normal: Unit<Vector>,
-        reflected: Vector,
+        reflected: Unit<Vector>,
     ) -> LinearColor {
         self.lights
             .spatial_lights_iter()
             .map(|light| {
                 let (direction, t) = light.to_source(&point);
-                let light_ray = Ray::new(point + 0.001 * direction, direction);
+                let light_ray = Ray::new(point + 0.001 * direction.as_ref(), direction);
                 match self.cast_ray(light_ray) {
                     // Take shadows into account
                     Some((obstacle_t, _)) if obstacle_t < t => return LinearColor::black(),

pathtracer/src/render/utils.rs

@@ -1,19 +1,19 @@
 use crate::Vector;
+use nalgebra::Unit;
 
-pub fn reflected(incident: Vector, normal: Vector) -> Vector {
+pub fn reflected(incident: Unit<Vector>, normal: Unit<Vector>) -> Unit<Vector> {
     let proj = incident.dot(&normal);
-    let delt = normal * (proj * 2.);
+    let delt = normal.into_inner() * (proj * 2.);
-    (incident - delt).normalize()
+    Unit::new_normalize(incident.as_ref() - delt)
 }
 
 /// Returns None if the ray was totally reflected, Some(refracted_ray, reflected_amount) if not
-/// Adds an element to the top of indices that should be removed
 pub fn refracted(
-    incident: Vector,
+    incident: Unit<Vector>,
-    normal: Vector,
+    normal: Unit<Vector>,
     indices: &mut RefractionInfo,
     new_index: f32,
-) -> Option<(Vector, f32)> {
+) -> Option<(Unit<Vector>, f32)> {
     let cos1 = incident.dot(&normal);
     let normal = if cos1 < 0. {
         // Entering object, change the medium
@@ -32,12 +32,12 @@ pub fn refracted(
     }
     let cos1 = cos1.abs();
     let cos2 = k.sqrt();
-    let refracted = eta * incident + (eta * cos1 - cos2) * normal;
+    let refracted = eta * incident.as_ref() + (eta * cos1 - cos2) * normal.as_ref();
     let f_r = (n_2 * cos1 - n_1 * cos2) / (n_2 * cos1 + n_1 * cos2);
     let f_t = (n_1 * cos2 - n_2 * cos1) / (n_1 * cos2 + n_2 * cos1);
     let refl_t = (f_r * f_r + f_t * f_t) / 2.;
     //Some((refracted, 0.))
-    Some((refracted.normalize(), refl_t))
+    Some((Unit::new_normalize(refracted), refl_t))
 }
 
 #[derive(Debug, PartialEq, Clone)]

pathtracer/src/serialize/vector.rs

@@ -1,15 +1,16 @@
 //! Helper functions to deserialize `Vector` values.
 
 use crate::Vector;
+use nalgebra::Unit;
 use serde::de::{Deserialize, Deserializer};
 
 /// Deserialize a vector.
 ///
 /// Needs a custom implementation to make sur the vector is normalized when deserialized.
-pub fn vector_normalizer<'de, D>(deserializer: D) -> Result<Vector, D::Error>
+pub fn vector_normalizer<'de, D>(deserializer: D) -> Result<Unit<Vector>, D::Error>
 where
     D: Deserializer<'de>,
 {
     let v: Vector = Deserialize::deserialize(deserializer)?;
-    Ok(v.normalize())
+    Ok(Unit::new_normalize(v))
 }

pathtracer/src/shape/mod.rs

@@ -1,10 +1,12 @@
 //! Various shape implementations
 
 use super::{Point, Point2D, Vector};
-use bvh::{
+use beevee::{
     aabb::{Bounded, AABB},
+    bvh::Intersected,
     ray::Ray,
 };
+use nalgebra::Unit;
 use serde::Deserialize;
 
 /// All the existing `Shape` implementation.
@@ -24,17 +26,29 @@ pub trait Shape: std::fmt::Debug {
     /// Return the distance at which the object intersects with the ray, or None if it does not.
     fn intersect(&self, ray: &Ray) -> Option<f32>;
     /// Return the unit vector corresponding to the normal at this point of the shape.
-    fn normal(&self, point: &Point) -> Vector;
+    fn normal(&self, point: &Point) -> Unit<Vector>;
     /// Project the point from the shape's surface to its texel coordinates.
     fn project_texel(&self, point: &Point) -> Point2D;
     /// Enclose the `Shape` in an axi-aligned bounding-box.
     fn aabb(&self) -> AABB;
+    /// Return the centroid of the shape.
+    fn centroid(&self) -> Point;
 }
 
 impl Bounded for dyn Shape {
     fn aabb(&self) -> AABB {
         self.aabb()
     }
+
+    fn centroid(&self) -> Point {
+        self.centroid()
+    }
+}
+
+impl Intersected for dyn Shape {
+    fn intersect(&self, ray: &Ray) -> Option<f32> {
+        self.intersect(ray)
+    }
 }
 
 mod sphere;

pathtracer/src/shape/sphere.rs

@@ -1,7 +1,8 @@
 use super::Shape;
 use crate::{Point, Point2D, Vector};
-use bvh::aabb::AABB;
+use beevee::aabb::AABB;
-use bvh::ray::Ray;
+use beevee::ray::Ray;
+use nalgebra::Unit;
 use serde::Deserialize;
 
 /// Represent a sphere shape inside the scene.
@@ -67,13 +68,13 @@ impl Shape for Sphere {
         }
     }
 
-    fn normal(&self, point: &Point) -> Vector {
+    fn normal(&self, point: &Point) -> Unit<Vector> {
         let delt = if self.inverted {
             self.center - point
         } else {
             point - self.center
         };
-        delt.normalize()
+        Unit::new_normalize(delt)
     }
 
     fn project_texel(&self, point: &Point) -> Point2D {
@@ -90,6 +91,10 @@ impl Shape for Sphere {
         let max = self.center + delt;
         AABB::with_bounds(min, max)
     }
+
+    fn centroid(&self) -> Point {
+        self.center
+    }
 }
 
 #[cfg(test)]
@@ -103,21 +108,30 @@ mod test {
     #[test]
     fn intersect_along_axis_works() {
         let sphere = simple_sphere();
-        let ray = Ray::new(Point::new(-2., 0., 0.), Vector::new(1., 0., 0.));
+        let ray = Ray::new(
+            Point::new(-2., 0., 0.),
+            Unit::new_normalize(Vector::new(1., 0., 0.)),
+        );
         assert_eq!(sphere.intersect(&ray), Some(1.))
     }
 
     #[test]
     fn non_intersect_along_axis_works() {
         let sphere = simple_sphere();
-        let ray = Ray::new(Point::new(-2., 0., 0.), Vector::new(-1., 0., 0.));
+        let ray = Ray::new(
+            Point::new(-2., 0., 0.),
+            Unit::new_normalize(Vector::new(-1., 0., 0.)),
+        );
         assert_eq!(sphere.intersect(&ray), None)
     }
 
     #[test]
     fn intersect_not_on_axis() {
         let sphere = simple_sphere();
-        let ray = Ray::new(Point::new(1., 1., 1.), Vector::new(-1., -1., -1.));
+        let ray = Ray::new(
+            Point::new(1., 1., 1.),
+            Unit::new_normalize(Vector::new(-1., -1., -1.)),
+        );
         assert_eq!(sphere.intersect(&ray), Some(f32::sqrt(3.) - 1.))
     }
 
@@ -126,7 +140,7 @@ mod test {
         let sphere = simple_sphere();
         assert_eq!(
             sphere.normal(&Point::new(-1., 0., 0.)),
-            Vector::new(-1., 0., 0.)
+            Unit::new_normalize(Vector::new(-1., 0., 0.))
         )
     }
 
@@ -135,7 +149,7 @@ mod test {
         let sphere = Sphere::inverted_new(Point::origin(), 1.);
         assert_eq!(
             sphere.normal(&Point::new(-1., 0., 0.)),
-            Vector::new(1., 0., 0.)
+            Unit::new_normalize(Vector::new(1., 0., 0.))
         )
     }
 

pathtracer/src/shape/triangle.rs

@@ -1,7 +1,8 @@
 use super::Shape;
 use crate::{Point, Point2D, Vector};
-use bvh::aabb::AABB;
+use beevee::aabb::AABB;
-use bvh::ray::Ray;
+use beevee::ray::Ray;
+use nalgebra::Unit;
 use serde::{Deserialize, Deserializer};
 
 /// Represent a triangle inside the scene.
@@ -88,8 +89,8 @@ impl Shape for Triangle {
         }
     }
 
-    fn normal(&self, _: &Point) -> Vector {
+    fn normal(&self, _: &Point) -> Unit<Vector> {
-        self.c0c1.cross(&self.c0c2).normalize()
+        Unit::new_normalize(self.c0c1.cross(&self.c0c2))
     }
 
     fn project_texel(&self, point: &Point) -> Point2D {
@@ -102,6 +103,10 @@ impl Shape for Triangle {
             .grow(&(self.c0 + self.c0c1))
             .grow(&(self.c0 + self.c0c2))
     }
+
+    fn centroid(&self) -> Point {
+        self.c0 + (self.c0c1 + self.c0c2) / 2.
+    }
 }
 
 #[derive(Debug, Deserialize)]
@@ -132,6 +137,7 @@ impl<'de> Deserialize<'de> for Triangle {
 #[cfg(test)]
 mod test {
     use super::*;
+    use nalgebra::Unit;
 
     fn simple_triangle() -> Triangle {
         Triangle::new(
@@ -146,7 +152,7 @@ mod test {
         let triangle = simple_triangle();
         let ans = triangle.intersect(&Ray::new(
             Point::new(-1., 0.5, 0.5),
-            Vector::new(1., 0., 0.),
+            Unit::new_normalize(Vector::new(1., 0., 0.)),
         ));
         assert_eq!(ans, Some(1.0))
     }
@@ -156,7 +162,7 @@ mod test {
         let triangle = simple_triangle();
         let ans = triangle.intersect(&Ray::new(
             Point::new(-1., 0.5, 0.),
-            Vector::new(1., 0., 0.5),
+            Unit::new_normalize(Vector::new(1., 0., 0.5)),
         ));
         assert!(ans.is_some());
         assert!((ans.unwrap() - f32::sqrt(1.0 + 0.25)).abs() < 1e-5)
@@ -165,7 +171,10 @@ mod test {
     #[test]
     fn intersect_out_of_bounds_is_none() {
         let triangle = simple_triangle();
-        let ans = triangle.intersect(&Ray::new(Point::new(-1., 0.5, 0.), Vector::new(1., 1., 1.)));
+        let ans = triangle.intersect(&Ray::new(
+            Point::new(-1., 0.5, 0.),
+            Unit::new_normalize(Vector::new(1., 1., 1.)),
+        ));
         assert_eq!(ans, None)
     }
 
@@ -173,7 +182,7 @@ mod test {
     fn normal_works() {
         let triangle = simple_triangle();
         let normal = triangle.normal(&Point::origin());
-        assert_eq!(normal, Vector::new(-1., 0., 0.));
+        assert_eq!(normal, Unit::new_normalize(Vector::new(-1., 0., 0.)));
     }
 
     #[test]