library: render: move helpers to utils module

Those helper functions are used by `Scene` to render the scene, but
they have no use being in the same file. Instead make it a crate-public
module of `render`.

src/render/mod.rs

@@ -8,3 +8,5 @@ pub use object::*;
 
 pub mod scene;
 pub use scene::*;
+
+pub(crate) mod utils;

src/render/scene.rs

@@ -2,7 +2,7 @@
 
 use std::cmp::Ordering;
 
-use super::{light_aggregate::LightAggregate, object::Object};
+use super::{light_aggregate::LightAggregate, object::Object, utils::*};
 use crate::{
     core::{Camera, LightProperties, LinearColor, ReflTransEnum},
     material::Material,
@@ -296,72 +296,6 @@ impl Scene {
     }
 }
 
-fn reflected(incident: Vector, normal: Vector) -> Vector {
-    let proj = incident.dot(&normal);
-    let delt = normal * (proj * 2.);
-    (incident - delt).normalize()
-}
-
-/// 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
-fn refracted(
-    incident: Vector,
-    normal: Vector,
-    indices: &mut RefractionInfo,
-    new_index: f32,
-) -> Option<(Vector, f32)> {
-    let cos1 = incident.dot(&normal);
-    let normal = if cos1 < 0. {
-        // Entering object, change the medium
-        indices.enter_medium(new_index); // The old index is now in old_index
-        normal
-    } else {
-        // Exiting object, exit the medium
-        indices.exit_medium(); // We swapped the indices
-        -normal
-    };
-    let (n_1, n_2) = (indices.old_index, indices.new_index);
-    let eta = n_1 / n_2;
-    let k = 1. - eta * eta * (1. - cos1 * cos1);
-    if k < 0. {
-        return None;
-    }
-    let cos1 = cos1.abs();
-    let cos2 = k.sqrt();
-    let refracted = eta * incident + (eta * cos1 - cos2) * normal;
-    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))
-}
-
-#[derive(Debug, PartialEq, Clone)]
-struct RefractionInfo {
-    pub old_index: f32,
-    pub new_index: f32,
-}
-
-impl RefractionInfo {
-    pub fn with_index(index: f32) -> Self {
-        RefractionInfo {
-            old_index: index,
-            new_index: index,
-        }
-    }
-
-    pub fn enter_medium(&mut self, index: f32) {
-        *self = RefractionInfo {
-            old_index: self.new_index,
-            new_index: index,
-        }
-    }
-
-    pub fn exit_medium(&mut self) {
-        std::mem::swap(&mut self.old_index, &mut self.new_index)
-    }
-}
-
 #[derive(Debug, PartialEq, Deserialize)]
 struct SerializedScene {
     camera: Camera,

src/render/utils.rs

@@ -0,0 +1,67 @@
+use crate::Vector;
+
+pub fn reflected(incident: Vector, normal: Vector) -> Vector {
+    let proj = incident.dot(&normal);
+    let delt = normal * (proj * 2.);
+    (incident - delt).normalize()
+}
+
+/// 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,
+    normal: Vector,
+    indices: &mut RefractionInfo,
+    new_index: f32,
+) -> Option<(Vector, f32)> {
+    let cos1 = incident.dot(&normal);
+    let normal = if cos1 < 0. {
+        // Entering object, change the medium
+        indices.enter_medium(new_index); // The old index is now in old_index
+        normal
+    } else {
+        // Exiting object, exit the medium
+        indices.exit_medium(); // We swapped the indices
+        -normal
+    };
+    let (n_1, n_2) = (indices.old_index, indices.new_index);
+    let eta = n_1 / n_2;
+    let k = 1. - eta * eta * (1. - cos1 * cos1);
+    if k < 0. {
+        return None;
+    }
+    let cos1 = cos1.abs();
+    let cos2 = k.sqrt();
+    let refracted = eta * incident + (eta * cos1 - cos2) * normal;
+    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))
+}
+
+#[derive(Debug, PartialEq, Clone)]
+pub struct RefractionInfo {
+    pub old_index: f32,
+    pub new_index: f32,
+}
+
+impl RefractionInfo {
+    pub fn with_index(index: f32) -> Self {
+        RefractionInfo {
+            old_index: index,
+            new_index: index,
+        }
+    }
+
+    pub fn enter_medium(&mut self, index: f32) {
+        *self = RefractionInfo {
+            old_index: self.new_index,
+            new_index: index,
+        }
+    }
+
+    pub fn exit_medium(&mut self) {
+        std::mem::swap(&mut self.old_index, &mut self.new_index)
+    }
+}