Added AVX2 enabled version of vec3 type, Updated readme

Cargo.lock

@@ -174,6 +174,12 @@ version = "0.2.86"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b7282d924be3275cec7f6756ff4121987bc6481325397dde6ba3e7802b1a8b1c"
 
+[[package]]
+name = "libm"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7fc7aa29613bd6a620df431842069224d8bc9011086b1db4c0e0cd47fa03ec9a"
+
 [[package]]
 name = "memoffset"
 version = "0.6.1"
@@ -243,6 +249,16 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "packed_simd_2"
+version = "0.3.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3278e0492f961fd4ae70909f56b2723a7e8d01a228427294e19cdfdebda89a17"
+dependencies = [
+ "cfg-if 0.1.10",
+ "libm",
+]
+
 [[package]]
 name = "png"
 version = "0.16.8"
@@ -332,6 +348,7 @@ version = "0.1.0"
 dependencies = [
  "image",
  "num-traits",
+ "packed_simd_2",
  "rand",
  "rayon",
  "sdl2",

Cargo.toml

@@ -6,6 +6,7 @@ version = "0.1.0"
 [dependencies]
 num-traits = "*"
 rayon = "1.5.0"
+packed_simd = { version = "0.3.4", package = "packed_simd_2" }
 
 [dependencies.image]
 default-features = false

README.md

@@ -2,6 +2,13 @@
 
 This is my attempt at Ray Tracing the Next Week book by Peter Shirley.
 
+
+On x86_64 target, It'll try to use AVX2. If you get build errors, Try commenting the simd_vec3 import in `src/types/mod.rs`.
+I tried changing the cfg attribute to, `all(target_arch = "x86_64", target_feature = "avx2")` but it keeps reporting that `avx2` feature is disabled on my machine?
+
+
+Without AVX2, The final scene takes ~33 seconds to render at a certain setting and with AVX2 the same scene takes ~23.5 seconds.
+
 [_Ray Tracing: The Next Week_](https://raytracing.github.io/books/RayTracingTheNextWeek.html)
 
 # Renders

src/aabb.rs

@@ -11,23 +11,17 @@ impl Aabb {
         Self { min, max }
     }
 
-    pub fn hit(&self, ray: &Ray, mut t_min: f64, mut t_max: f64) -> bool {
+    pub fn hit(&self, ray: &Ray, t_min: f64, t_max: f64) -> bool {
-        for i in 0..=2 {
+        let min = (self.min - ray.origin) / ray.direction;
-            let inverse_dir = 1.0 / ray.direction[i];
+        let max = (self.max - ray.origin) / ray.direction;
-            let mut t0 = (self.min[i] - ray.origin[i]) * inverse_dir;
-            let mut t1 = (self.max[i] - ray.origin[i]) * inverse_dir;
-            if inverse_dir < 0.0 {
-                std::mem::swap(&mut t0, &mut t1);
-            }
-            t_min = if t0 > t_min { t0 } else { t_min };
-            t_max = if t1 < t_max { t1 } else { t_max };
 
-            if t_max <= t_min {
+        let mins = min.min(max);
-                return false;
+        let maxs = min.max(max);
-            }
-        }
 
-        true
+        let tmin = mins.max_element(t_min);
+        let tmax = maxs.min_element(t_max);
+
+        tmax > tmin
     }
 
     pub fn surrounding_box(box0: Aabb, box1: Aabb) -> Self {

src/main.rs

@@ -22,11 +22,11 @@ use std::time::Instant;
 pub trait Asf64: num_traits::AsPrimitive<f64> {}
 impl<T: num_traits::AsPrimitive<f64>> Asf64 for T {}
 
-const NUM_SAMPLES: u16 = 10000;
+const NUM_SAMPLES: u16 = 500;
 const VERTICAL_PARTITION: usize = 12;
 const HORIZONTAL_PARTITION: usize = 12;
-const WIDTH: usize = 1500;
+const WIDTH: usize = 500;
-const HEIGHT: usize = 1500;
+const HEIGHT: usize = 500;
 
 fn main() -> Result<(), String> {
     run(WIDTH, HEIGHT)

src/types/mod.rs

@@ -1,9 +1,17 @@
 mod color;
 mod dimension;
 mod ray;
-mod vec3;
 
 pub use color::Color;
 pub use dimension::{Dimension, X, Y, Z};
 pub use ray::Ray;
+
+#[cfg(not(target_arch = "x86_64"))]
+mod vec3;
+#[cfg(not(target_arch = "x86_64"))]
 pub use vec3::Vec3;
+
+#[cfg(target_arch = "x86_64")]
+mod simd_vec3;
+#[cfg(target_arch = "x86_64")]
+pub use simd_vec3::Vec3;

src/types/simd_vec3.rs

@@ -0,0 +1,214 @@
+use std::{
+    fmt::{Display, Formatter, Result as FmtResult},
+    ops::{Add, AddAssign, Div, DivAssign, Mul, MulAssign, Neg, RangeInclusive, Sub, SubAssign},
+};
+
+use rand::Rng;
+
+use crate::{Asf64, Dimension, X, Y, Z};
+
+use packed_simd::{f64x4, shuffle};
+
+#[derive(Default, Debug, Copy, Clone)]
+pub struct Vec3(f64x4);
+
+impl Vec3 {
+    #[inline]
+    pub fn new(a: impl Asf64, b: impl Asf64, c: impl Asf64) -> Vec3 {
+        Self(f64x4::new(a.as_(), b.as_(), c.as_(), 0.0))
+    }
+
+    pub fn splat(xyz: impl Asf64) -> Self {
+        Self::new(xyz, xyz, xyz)
+    }
+
+    pub fn random<R: Rng + ?Sized>(rng: &mut R) -> Self {
+        Self(f64x4::from_slice_aligned(&rng.gen::<[f64; 4]>()))
+    }
+
+    pub fn random_in_range<R: Rng + ?Sized>(rng: &mut R, range: RangeInclusive<f64>) -> Self {
+        Vec3::new(
+            rng.gen_range(range.clone()),
+            rng.gen_range(range.clone()),
+            rng.gen_range(range),
+        )
+    }
+
+    #[inline]
+    pub fn x(&self) -> f64 {
+        self.get::<X>()
+    }
+    #[inline]
+    pub fn y(&self) -> f64 {
+        self.get::<Y>()
+    }
+    #[inline]
+    pub fn z(&self) -> f64 {
+        self.get::<Z>()
+    }
+
+    pub fn get<D: Dimension>(&self) -> f64 {
+        unsafe { self.0.extract_unchecked(D::INDEX) }
+    }
+
+    pub fn set<D: Dimension>(self, value: f64) -> Self {
+        Self(unsafe { self.0.replace_unchecked(D::INDEX, value) })
+    }
+
+    #[inline]
+    pub fn length(&self) -> f64 {
+        self.sq_len().sqrt()
+    }
+
+    #[inline]
+    pub fn sq_len(&self) -> f64 {
+        (self.0 * self.0).sum()
+    }
+
+    #[inline]
+    pub fn dot(&self, v: &Vec3) -> f64 {
+        (self.0 * v.0).sum()
+    }
+
+    #[inline]
+    pub fn cross(&self, v: &Vec3) -> Vec3 {
+        // https://web.archive.org/web/20210412192227/https://geometrian.com/programming/tutorials/cross-product/index.php
+        let tmp0: f64x4 = shuffle!(self.0, [1, 2, 0, 3]);
+        let tmp1: f64x4 = shuffle!(v.0, [2, 0, 1, 3]);
+        let tmp2: f64x4 = shuffle!(self.0, [2, 0, 1, 3]);
+        let tmp3: f64x4 = shuffle!(v.0, [1, 2, 0, 3]);
+
+        Vec3(tmp0 * tmp1 - tmp2 * tmp3)
+    }
+
+    #[inline]
+    pub fn unit_vector(self) -> Vec3 {
+        self / self.length()
+    }
+
+    pub fn min(self, other: Self) -> Vec3 {
+        Self(self.0.min(other.0))
+    }
+
+    pub fn max(self, other: Self) -> Vec3 {
+        Self(self.0.max(other.0))
+    }
+
+    pub fn min_element(self, other: f64) -> f64 {
+        unsafe { self.0.replace_unchecked(3, other).min_element() }
+    }
+
+    pub fn max_element(self, other: f64) -> f64 {
+        unsafe { self.0.replace_unchecked(3, other).max_element() }
+    }
+
+    #[inline]
+    pub fn sqrt(self) -> Self {
+        Self(self.0.sqrt())
+    }
+}
+
+impl Add for Vec3 {
+    type Output = Vec3;
+
+    fn add(self, o: Vec3) -> Vec3 {
+        Vec3(self.0 + o.0)
+    }
+}
+
+impl AddAssign for Vec3 {
+    fn add_assign(&mut self, o: Vec3) {
+        self.0 += o.0
+    }
+}
+
+impl Sub for Vec3 {
+    type Output = Vec3;
+
+    fn sub(self, o: Vec3) -> Vec3 {
+        Vec3(self.0 - o.0)
+    }
+}
+
+impl SubAssign for Vec3 {
+    fn sub_assign(&mut self, o: Vec3) {
+        self.0 -= o.0;
+    }
+}
+
+impl Neg for Vec3 {
+    type Output = Vec3;
+
+    fn neg(self) -> Vec3 {
+        Vec3(-self.0)
+    }
+}
+
+impl MulAssign<Vec3> for Vec3 {
+    fn mul_assign(&mut self, o: Vec3) {
+        self.0 *= o.0
+    }
+}
+
+impl MulAssign<f64> for Vec3 {
+    fn mul_assign(&mut self, o: f64) {
+        self.0 *= o
+    }
+}
+
+impl Mul<f64> for Vec3 {
+    type Output = Vec3;
+    fn mul(self, o: f64) -> Vec3 {
+        Vec3(self.0 * o)
+    }
+}
+
+impl Mul<Vec3> for Vec3 {
+    type Output = Vec3;
+    fn mul(self, o: Vec3) -> Vec3 {
+        Vec3(self.0 * o.0)
+    }
+}
+
+impl Div<Vec3> for Vec3 {
+    type Output = Vec3;
+
+    fn div(self, o: Vec3) -> Vec3 {
+        Vec3(self.0 / o.0)
+    }
+}
+
+impl Div<f64> for Vec3 {
+    type Output = Vec3;
+
+    fn div(self, o: f64) -> Vec3 {
+        let o = 1.0 / o;
+
+        Vec3(self.0 * o)
+    }
+}
+
+impl DivAssign<f64> for Vec3 {
+    fn div_assign(&mut self, o: f64) {
+        let o = 1.0 / o;
+
+        self.0 *= o
+    }
+}
+
+impl Display for Vec3 {
+    fn fmt(&self, f: &mut Formatter) -> FmtResult {
+        f.write_fmt(format_args!(
+            "{} {} {}",
+            self.get::<X>(),
+            self.get::<Y>(),
+            self.get::<Z>()
+        ))
+    }
+}
+
+impl<A: Asf64, B: Asf64, C: Asf64> From<(A, B, C)> for Vec3 {
+    fn from((x, y, z): (A, B, C)) -> Self {
+        Self::new(x, y, z)
+    }
+}

src/types/vec3.rs

@@ -16,7 +16,7 @@ pub struct Vec3([f64; 3]);
 impl Vec3 {
     #[inline]
     pub fn new(a: impl Asf64, b: impl Asf64, c: impl Asf64) -> Vec3 {
-        Vec3([a.as_(), b.as_(), c.as_()])
+        Self([a.as_(), b.as_(), c.as_()])
     }
 
     pub fn splat(xyz: impl Asf64) -> Self {
@@ -102,12 +102,12 @@ impl Vec3 {
         ])
     }
 
-    pub fn min_element(self) -> f64 {
+    pub fn min_element(self, other: f64) -> f64 {
-        self.x().min(self.y()).min(self.z())
+        self.x().min(self.y()).min(self.z()).min(other)
     }
 
-    pub fn max_element(self) -> f64 {
+    pub fn max_element(self, other: f64) -> f64 {
-        self.x().max(self.y()).max(self.z())
+        self.x().max(self.y()).max(self.z()).max(other)
     }
 
     #[inline]