library: move from f64 to f32

They are faster to compute with, take less space --which means faster
access because we use less cache lines--, and they are what is used by
`bvh`...

src/core/color.rs

@@ -5,9 +5,9 @@ use derive_more::{Add, AddAssign, Div, DivAssign, Mul, MulAssign, Sub, SubAssign
 )]
 /// A structure to represent operations in the linear RGB colorspace.
 pub struct LinearColor {
-    pub r: f64,
-    pub g: f64,
-    pub b: f64,
+    pub r: f32,
+    pub g: f32,
+    pub b: f32,
 }
 
 impl LinearColor {
@@ -19,7 +19,7 @@ impl LinearColor {
         }
     }
 
-    pub fn new(r: f64, g: f64, b: f64) -> Self {
+    pub fn new(r: f32, g: f32, b: f32) -> Self {
         LinearColor { r, g, b }
     }
 }

src/lib.rs

@@ -1,8 +1,8 @@
 use bvh::nalgebra::{Point2, Point3, Vector3};
 
-pub type Point2D = Point2<f64>;
-pub type Point = Point3<f64>;
-pub type Vector = Vector3<f64>;
+pub type Point2D = Point2<f32>;
+pub type Point = Point3<f32>;
+pub type Vector = Vector3<f32>;
 
 pub mod core;
 pub mod light;

src/light/mod.rs

@@ -10,5 +10,5 @@ pub trait Light: std::fmt::Debug {
 /// Represent a light which has an abstract position in the scene being rendered.
 pub trait SpatialLight: Light {
     /// Get a unit vector from the origin to the position of the light, and its distance
-    fn to_source(&self, origin: &Point) -> (Vector, f64);
+    fn to_source(&self, origin: &Point) -> (Vector, f32);
 }

src/shape/mod.rs

@@ -5,9 +5,12 @@ use bvh::ray::Ray;
 /// Represent an abstract shape inside the scene.
 pub trait Shape: Bounded + std::fmt::Debug {
     /// Return the distance at which the object intersects with the ray, or None if it does not.
-    fn intersect(&self, ray: &Ray) -> Option<f64>;
+    fn intersect(&self, ray: &Ray) -> Option<f32>;
     /// Return the unit vector corresponding to the normal at this point of the shape.
     fn normal(&self, point: &Point) -> Vector;
     /// Project the point from the shape's surface to its texel coordinates.
     fn project_texel(&self, point: &Point) -> Point2D;
 }
+
+pub mod sphere;
+pub use sphere::*;