Fix a vector negation bug.

ray-tracer/src/bin/sphere.rs

@@ -6,7 +6,14 @@ use std::{
     sync::{Arc, RwLock},
 };
 
-const SIZE: usize = 100;
+const SIZE: usize = 1000;
+
+const EPSILON: f64 = 0.00001;
+
+fn eq_f64(l: f64, r: f64) -> bool {
+    (l - r).abs() < EPSILON
+}
+
 
 fn render(
     camera: &Point,
@@ -23,6 +30,7 @@ fn render(
 
     let ray = Ray::new(camera.clone(), (Point::new(0., 0., wall_z) - camera).normalize());
     let xs = ray.intersect(sphere);
+    /*
     match xs.hit() {
         Some(hit) => {
             let point = ray.position(hit.t);
@@ -33,6 +41,7 @@ fn render(
         }
         None => {}
     }
+    */
 
     (0..SIZE).into_par_iter().for_each(|x| {
         (0..SIZE).into_par_iter().for_each(|y| {
@@ -47,6 +56,7 @@ fn render(
                     let point = ray.position(hit.t);
                     let normal = hit.object.normal_at(&point);
                     let eye = -ray.direction;
+
                     let color = hit
                         .object
                         .material()
@@ -73,29 +83,43 @@ fn main() {
     let camera = Point::new(0., 0., -5.);
     let wall_z = 10.;
     let wall_size = 7.;
+    let light = PointLight::new(Point::new(-5., 5., -10.), Color::new(1., 1., 1.));
 
+    render(&camera, &light, &sphere, wall_z, wall_size, "sphere_1.ppm");
+    /*
     {
         let light = PointLight::new(Point::new(0., 0., -10.), Color::new(1., 1., 1.));
+        println!("Light at {:0.2} {:0.2} {:0.2}", light.position.x(), light.position.y(), light.position.z());
         render(&camera, &light, &sphere, wall_z, wall_size, "sphere_1.ppm");
+        println!();
     }
 
     {
-        let light = PointLight::new(Point::new(-1., 0., -10.), Color::new(1., 1., 1.));
+        let light = PointLight::new(Point::new(-2., 0., -10.), Color::new(1., 1., 1.));
+        println!("Light at {:0.2} {:0.2} {:0.2}", light.position.x(), light.position.y(), light.position.z());
         render(&camera, &light, &sphere, wall_z, wall_size, "sphere_2.ppm");
+        println!();
     }
 
     {
-        let light = PointLight::new(Point::new(1., 0., -10.), Color::new(1., 1., 1.));
+        let light = PointLight::new(Point::new(2., 0., -10.), Color::new(1., 1., 1.));
+        println!("Light at {:0.2} {:0.2} {:0.2}", light.position.x(), light.position.y(), light.position.z());
         render(&camera, &light, &sphere, wall_z, wall_size, "sphere_3.ppm");
+        println!();
     }
 
     {
-        let light = PointLight::new(Point::new(0., -1., -10.), Color::new(1., 1., 1.));
+        let light = PointLight::new(Point::new(0., -2., -10.), Color::new(1., 1., 1.));
+        println!("Light at {:0.2} {:0.2} {:0.2}", light.position.x(), light.position.y(), light.position.z());
         render(&camera, &light, &sphere, wall_z, wall_size, "sphere_4.ppm");
+        println!();
     }
 
     {
-        let light = PointLight::new(Point::new(0., 1., -10.), Color::new(1., 1., 1.));
+        let light = PointLight::new(Point::new(0., 2., -10.), Color::new(1., 1., 1.));
+        println!("Light at {:0.2} {:0.2} {:0.2}", light.position.x(), light.position.y(), light.position.z());
         render(&camera, &light, &sphere, wall_z, wall_size, "sphere_5.ppm");
+        println!();
     }
+    */
 }

ray-tracer/src/types/material.rs

@@ -1,4 +1,4 @@
-use super::{Color, Point, PointLight, Vector};
+use super::{eq_f64, Color, Point, PointLight, Vector};
 
 #[derive(Debug, PartialEq)]
 pub struct Material {
@@ -22,7 +22,25 @@ impl Default for Material {
 }
 
 impl Material {
-    pub fn lighting(&self, light: &PointLight, position: &Point, eye: &Vector, normal_v: &Vector) -> Color {
+    pub fn lighting(
+        &self,
+        light: &PointLight,
+        position: &Point,
+        eye: &Vector,
+        normal_v: &Vector,
+    ) -> Color {
+        // let debug = eq_f64(position.x(), -0.09344)
+        //     || eq_f64(position.x(), 0.09344) && eq_f64(position.y(), 0.)
+        //     || eq_f64(position.y(), -0.09344)
+        //     || eq_f64(position.y(), 0.09344) && eq_f64(position.x(), 0.);
+        // if debug {
+        //     println!(
+        //         "Debugging {:0.5} {:0.5} {:0.5}",
+        //         position.x(),
+        //         position.y(),
+        //         position.z()
+        //     );
+        // }
         let effective_color = self.color * light.intensity;
 
         let light_v = (light.position - position).normalize();
@@ -53,8 +71,8 @@ impl Material {
 
 #[cfg(test)]
 mod tests {
-    use crate::types::{Color, Point, PointLight, Vector};
     use super::*;
+    use crate::types::{Color, Point, PointLight, Vector};
 
     #[test]
     fn lighting_with_eye_between_light_and_surface() {
@@ -65,7 +83,10 @@ mod tests {
         let normalv = Vector::new(0., 0., -1.);
         let light = PointLight::new(Point::new(0., 0., -10.), Color::new(1., 1., 1.));
 
-        assert_eq!(m.lighting(&light, &position, &eyev, &normalv), Color::new(1.9, 1.9, 1.9));
+        assert_eq!(
+            m.lighting(&light, &position, &eyev, &normalv),
+            Color::new(1.9, 1.9, 1.9)
+        );
     }
 
     #[test]
@@ -77,7 +98,10 @@ mod tests {
         let normalv = Vector::new(0., 0., -1.);
         let light = PointLight::new(Point::new(0., 0., -10.), Color::new(1., 1., 1.));
 
-        assert_eq!(m.lighting(&light, &position, &eyev, &normalv), Color::new(1., 1., 1.));
+        assert_eq!(
+            m.lighting(&light, &position, &eyev, &normalv),
+            Color::new(1., 1., 1.)
+        );
     }
 
     #[test]
@@ -89,7 +113,10 @@ mod tests {
         let normalv = Vector::new(0., 0., -1.);
         let light = PointLight::new(Point::new(0., 10., -10.), Color::new(1., 1., 1.));
 
-        assert_eq!(m.lighting(&light, &position, &eyev, &normalv), Color::new(0.7364, 0.7364, 0.7364));
+        assert_eq!(
+            m.lighting(&light, &position, &eyev, &normalv),
+            Color::new(0.7364, 0.7364, 0.7364)
+        );
     }
 
     #[test]
@@ -102,7 +129,10 @@ mod tests {
         let normalv = Vector::new(0., 0., -1.);
         let light = PointLight::new(Point::new(0., 10., -10.), Color::new(1., 1., 1.));
 
-        assert_eq!(m.lighting(&light, &position, &eyev, &normalv), Color::new(1.6364, 1.6364, 1.6364));
+        assert_eq!(
+            m.lighting(&light, &position, &eyev, &normalv),
+            Color::new(1.6364, 1.6364, 1.6364)
+        );
     }
 
     #[test]
@@ -114,6 +144,9 @@ mod tests {
         let normalv = Vector::new(0., 0., -1.);
         let light = PointLight::new(Point::new(0., 0., 10.), Color::new(1., 1., 1.));
 
-        assert_eq!(m.lighting(&light, &position, &eyev, &normalv), Color::new(0.1, 0.1, 0.1));
+        assert_eq!(
+            m.lighting(&light, &position, &eyev, &normalv),
+            Color::new(0.1, 0.1, 0.1)
+        );
     }
 }

ray-tracer/src/types/vector.rs

@@ -106,9 +106,7 @@ impl std::ops::Sub for Vector {
 impl std::ops::Neg for Vector {
     type Output = Vector;
     fn neg(self) -> Self::Output {
-        let mut t = -self.0;
-        t.0 = 0.;
-        Vector::from(t)
+        Vector::from(-self.0)
     }
 }