first diffused sphere

src/vec3.rs

@@ -1,5 +1,7 @@
 use std::{ops::{Add, Sub, AddAssign, SubAssign, Mul, Div, MulAssign, DivAssign}};
 
+use crate::rtweekend::{random_f64, random_range_f64};
+
 #[derive(Debug, Clone, Copy)]
 pub struct Vec3 {
     pub elements: [f64; 3],
@@ -49,6 +51,14 @@ impl Vec3 {
     pub fn unit_vector(self) -> Self {
         self / self.length()
     }
+
+    pub fn random() -> Self {
+        Vec3::new(random_f64(), random_f64(), random_f64())
+    }
+
+    pub fn random_range(min: f64, max: f64) -> Self {
+        Vec3::new(random_range_f64(min, max), random_range_f64(min, max), random_range_f64(min, max))
+    }
 }
 
 impl Add for Vec3 {
@@ -165,4 +175,14 @@ impl DivAssign<f64> for Vec3 {
 }
 
 pub type Color = Vec3;
-pub type Point3 = Vec3;
+pub type Point3 = Vec3;
+
+pub fn random_in_unit_sphere() -> Vec3 {
+    loop {
+        let p = Vec3::random_range(-1.0, 1.0);
+        if p.length_squared() >= 1.0 {
+            continue;
+        }
+        return p;
+    }
+}