Create utils instead

3 files changed, 68 insertions, 43 deletions

diff --git a/src/colour.rs b/src/colour.rs
deleted file mode 100644
index 0d5e705..0000000
--- a/src/colour.rs
+++ /dev/null
@@ -1,15 +0,0 @@
-use cgmath::Vector3;
-
-pub fn clamp(x: f64, min: f64, max: f64) -> f64 {
-    if x < min { min }
-    else if x > max { max }
-    else { x }
-}
-
-pub fn print_colour(colour: &Vector3<f64>, samples: i32) {
-    let scolour = colour.map(|x| (x / samples as f64).sqrt());
-    println!("{} {} {}"
-             , (256.0 * clamp(scolour.x, 0.0, 0.999)) as i32
-             , (256.0 * clamp(scolour.y, 0.0, 0.999)) as i32
-             , (256.0 * clamp(scolour.z, 0.0, 0.999)) as i32)
-}
diff --git a/src/random.rs b/src/random.rs
deleted file mode 100644
index 66c637a..0000000
--- a/src/random.rs
+++ /dev/null
@@ -1,28 +0,0 @@
-use cgmath::prelude::*;
-use cgmath::{Vector3, vec3, dot};
-use rand::prelude::*;
-use std::f64::consts::PI;
-
-pub fn random_vector3(rng: &mut ThreadRng, min: f64, max: f64) -> Vector3<f64> {
-    vec3(rng.gen_range(min, max), rng.gen_range(min, max), rng.gen_range(min, max))
-}
-
-pub fn random_in_unit_sphere(rng: &mut ThreadRng) -> Vector3<f64> {
-    loop {
-        let p = random_vector3(rng, -1.0, 1.0);
-        if p.magnitude2() <= 1.0 { return p }
-    }
-}
-
-pub fn random_unit_vector(rng: &mut ThreadRng) -> Vector3<f64> {
-    let a = rng.gen_range(0.0, 2.0*PI);
-    let z = rng.gen_range(-1.0, 1.0);
-    let r = ((1.0 - z*z) as f64).sqrt();
-    vec3(r*a.cos(), r*a.sin(), z)
-}
-
-pub fn random_in_hemisphere(rng: &mut ThreadRng, normal: &Vector3<f64>) -> Vector3<f64> {
-    let in_unit_sphere = random_in_unit_sphere(rng);
-    if dot(in_unit_sphere, *normal) > 0.0 { in_unit_sphere }
-    else { -in_unit_sphere }
-}
diff --git a/src/utils.rs b/src/utils.rs
new file mode 100644
index 0000000..659de7d
--- /dev/null
+++ b/src/utils.rs
@@ -0,0 +1,68 @@
+use cgmath::prelude::*;
+use cgmath::{Vector3, vec3, dot};
+use rand::prelude::*;
+use std::f64::consts::PI;
+
+pub fn clamp(x: f64, min: f64, max: f64) -> f64 {
+    if x < min { min }
+    else if x > max { max }
+    else { x }
+}
+
+pub fn print_colour(colour: &Vector3<f64>, samples: i32) {
+    let scolour = colour.map(|x| (x / samples as f64).sqrt());
+    println!("{} {} {}"
+             , (256.0 * clamp(scolour.x, 0.0, 0.999)) as i32
+             , (256.0 * clamp(scolour.y, 0.0, 0.999)) as i32
+             , (256.0 * clamp(scolour.z, 0.0, 0.999)) as i32)
+}
+
+pub fn random_vector3(rng: &mut ThreadRng, min: f64, max: f64) -> Vector3<f64> {
+    vec3(rng.gen_range(min, max), rng.gen_range(min, max), rng.gen_range(min, max))
+}
+
+pub fn random_in_unit_sphere(rng: &mut ThreadRng) -> Vector3<f64> {
+    loop {
+        let p = random_vector3(rng, -1.0, 1.0);
+        if p.magnitude2() <= 1.0 { return p }
+    }
+}
+
+pub fn random_unit_vector(rng: &mut ThreadRng) -> Vector3<f64> {
+    let a = rng.gen_range(0.0, 2.0*PI);
+    let z = rng.gen_range(-1.0, 1.0);
+    let r = ((1.0 - z*z) as f64).sqrt();
+    vec3(r*a.cos(), r*a.sin(), z)
+}
+
+pub fn random_in_hemisphere(rng: &mut ThreadRng, normal: &Vector3<f64>) -> Vector3<f64> {
+    let in_unit_sphere = random_in_unit_sphere(rng);
+    if dot(in_unit_sphere, *normal) > 0.0 { in_unit_sphere }
+    else { -in_unit_sphere }
+}
+
+pub fn random_in_unit_disk(rng: &mut ThreadRng) -> Vector3<f64> {
+    loop {
+        let p = vec3(rng.gen_range(-1.0, 1.0), rng.gen_range(-1.0, 1.0), 0.0);
+        if p.magnitude2() < 1.0 {
+            return p
+        }
+    }
+}
+
+pub fn reflect(v: &Vector3<f64>, n: &Vector3<f64>) -> Vector3<f64> {
+    v - 2.0 * dot(*v, *n) * n
+}
+
+pub fn refract(uv: &Vector3<f64>, n: &Vector3<f64>, etai_over_etat: f64) -> Vector3<f64> {
+    let cos_theta = dot(-1.0 * uv, *n);
+    let r_out_parallel =  etai_over_etat * (uv + cos_theta*n);
+    let r_out_perp = -(1.0 - r_out_parallel.magnitude2()).sqrt() * n;
+    r_out_parallel + r_out_perp
+}
+
+pub fn schlick(cosine: f64, ref_idx: f64) -> f64 {
+    let r0 = (1.0 - ref_idx) / (1.0 + ref_idx);
+    let r0sq = r0*r0;
+    r0sq + (1.0 - r0) * (1.0 - cosine).powi(5)
+}