From 78ddaff5855bf8446adef9e18eb0d7b7ddcee52a Mon Sep 17 00:00:00 2001
From: lamp
Date: Sun, 5 Mar 2023 21:45:56 +0000
Subject: init

---
 src/vec3.rs | 201 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 201 insertions(+)
 create mode 100644 src/vec3.rs

(limited to 'src/vec3.rs')

diff --git a/src/vec3.rs b/src/vec3.rs
new file mode 100644
index 0000000..8525fdd
--- /dev/null
+++ b/src/vec3.rs
@@ -0,0 +1,201 @@
+use auto_ops::{impl_op_ex, impl_op_ex_commutative};
+use std::fmt;
+
+pub type Point3 = Vec3;
+pub type Color = Vec3;
+
+#[derive(Clone, Default)]
+pub struct Vec3 {
+    pub x: f64,
+    pub y: f64,
+    pub z: f64,
+}
+
+impl Vec3 {
+    pub fn new() -> Vec3 {
+        Vec3 {
+            x: 0.0,
+            y: 0.0,
+            z: 0.0,
+        }
+    }
+
+    pub fn get(&self, index: usize) -> Option<&f64> {
+        match index {
+            0 => Some(&self.x),
+            1 => Some(&self.y),
+            2 => Some(&self.z),
+            _ => None,
+        }
+    }
+
+    pub fn get_mut(&mut self, index: usize) -> Option<&mut f64> {
+        match index {
+            0 => Some(&mut self.x),
+            1 => Some(&mut self.y),
+            2 => Some(&mut self.z),
+            _ => None,
+        }
+    }
+
+    pub fn length(&self) -> f64 {
+        self.length_squared().sqrt()
+    }
+
+    pub fn length_squared(&self) -> f64 {
+        self.x * self.x + self.y * self.y + self.z * self.z
+    }
+
+    pub fn dot(&self, other: &Vec3) -> f64 {
+        self.x * other.x + self.y * other.y + self.z * other.z
+    }
+
+    pub fn cross(&self, other: &Vec3) -> Vec3 {
+        Vec3 {
+            x: self.y * other.z - self.z * other.y,
+            y: self.z * other.x - self.x * other.z,
+            z: self.x * other.y - self.y * other.x,
+        }
+    }
+
+    pub fn unit_vector(&self) -> Vec3 {
+        self / self.length()
+    }
+
+    pub fn random() -> Vec3 {
+        Vec3 {
+            x: rand::random::<f64>(),
+            y: rand::random::<f64>(),
+            z: rand::random::<f64>(),
+        }
+    }
+
+    pub fn random_in_range(min: f64, max: f64) -> Vec3 {
+        Vec3 {
+            x: min + (max - min) * rand::random::<f64>(),
+            y: min + (max - min) * rand::random::<f64>(),
+            z: min + (max - min) * rand::random::<f64>(),
+        }
+    }
+
+    pub fn random_in_unit_sphere() -> Vec3 {
+        loop {
+            let p = Vec3 {
+                x: 2.0 * rand::random::<f64>() - 1.0,
+                y: 2.0 * rand::random::<f64>() - 1.0,
+                z: 2.0 * rand::random::<f64>() - 1.0,
+            };
+            if p.length_squared() < 1.0 {
+                return p;
+            }
+        };
+    }
+
+    pub fn random_unit_vector() -> Vec3 {
+        Self::random_in_unit_sphere().unit_vector()
+    }
+
+    pub fn random_in_unit_disk() -> Vec3 {
+        loop {
+            let p = Vec3 {
+                x: 2.0 * rand::random::<f64>() -1.0,
+                y: 2.0 * rand::random::<f64>() -1.0,
+                z: 0.0,
+            };
+            if p.length_squared() < 1.0 {
+                return p;
+            }
+        }
+    }
+
+    pub fn near_zero(&self) -> bool {
+        const S: f64 = 1e-8;
+        self.x.abs() < S && self.y.abs() < S && self.z.abs() < S
+    }
+
+    pub fn reflect(&self, normal: &Vec3) -> Vec3 {
+        self - 2.0 * self.dot(normal) * normal
+    }
+
+    pub fn refract(&self, normal: &Vec3, etai_over_etat: f64) -> Vec3 {
+        let cos_theta = normal.dot(&-self).min(1.0);
+        let r_out_perp = etai_over_etat * (self + cos_theta * normal);
+        let r_out_parallel = -((1.0 - r_out_perp.length_squared()).abs().sqrt()) * normal;
+        r_out_perp + r_out_parallel
+    }
+
+    pub fn has_infinite_member(&self) -> bool {
+        self.x.is_infinite() || self.y.is_infinite() || self.z.is_infinite()
+    }
+}
+
+impl fmt::Display for Vec3 {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{} {} {}", self.x, self.y, self.z)
+    }
+}
+
+impl<'a> IntoIterator for &'a Vec3 {
+    type Item = f64;
+    type IntoIter = Vec3Iterator<'a>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        Vec3Iterator {
+            vec3: self,
+            index: 0,
+        }
+    }
+}
+
+pub struct Vec3Iterator<'a> {
+    vec3: &'a Vec3,
+    index: usize,
+}
+
+impl<'a> Iterator for Vec3Iterator<'a> {
+    type Item = f64;
+    fn next(&mut self) -> Option<f64> {
+        let result = match self.index {
+            0 => self.vec3.x,
+            1 => self.vec3.y,
+            2 => self.vec3.z,
+            _ => return None,
+        };
+        self.index += 1;
+        Some(result)
+    }
+}
+
+impl_op_ex!(- |a: &Vec3| -> Vec3 {
+    Vec3 {
+        x: -a.x,
+        y: -a.y,
+        z: -a.z,
+    }
+});
+impl_op_ex!(+= |lhs: &mut Vec3, rhs: Vec3| { *lhs = Vec3 { x: lhs.x + rhs.x, y: lhs.y + rhs.y, z: lhs.z + rhs.z } });
+impl_op_ex!(*= |lhs: &mut Vec3, rhs: &f64| { *lhs = Vec3 { x: lhs.x * rhs, y: lhs.y * rhs, z: lhs.z * rhs } });
+impl_op_ex!(/= |lhs: &mut Vec3, rhs: &f64| { *lhs *= 1.0 / rhs });
+impl_op_ex!(+ |lhs: &Vec3, rhs: &Vec3| -> Vec3 { Vec3 { x: lhs.x + rhs.x, y: lhs.y + rhs.y, z: lhs.z + rhs.z } });
+impl_op_ex!(-|lhs: &Vec3, rhs: &Vec3| -> Vec3 {
+    Vec3 {
+        x: lhs.x - rhs.x,
+        y: lhs.y - rhs.y,
+        z: lhs.z - rhs.z,
+    }
+});
+impl_op_ex!(*|lhs: &Vec3, rhs: &Vec3| -> Vec3 {
+    Vec3 {
+        x: lhs.x * rhs.x,
+        y: lhs.y * rhs.y,
+        z: lhs.z * rhs.z,
+    }
+});
+impl_op_ex_commutative!(*|lhs: &Vec3, rhs: &f64| -> Vec3 {
+    Vec3 {
+        x: lhs.x * rhs,
+        y: lhs.y * rhs,
+        z: lhs.z * rhs,
+    }
+});
+impl_op_ex!(/ |lhs: &Vec3, rhs: &f64| -> Vec3 { lhs * (1.0/rhs) });
-- 
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