Clippy warnings

ray-tracer/src/bin/projectile.rs

@@ -49,5 +49,5 @@ fn main() {
     let ppm = PPM::from(canvas);
 
     let mut file = File::create("projectile.ppm").unwrap();
-    file.write(ppm.as_bytes()).unwrap();
+    let _ = file.write(ppm.as_bytes());
 }

ray-tracer/src/ppm.rs

@@ -8,8 +8,7 @@ fn join_to_line_limit(data: impl IntoIterator<Item = String>) -> Vec<String> {
     let mut lines = vec![];
 
     let mut line = String::new();
-    let mut iter = data.into_iter();
-    while let Some(element) = iter.next() {
+    for element in data {
         if line.is_empty() {
             line = line + &element;
         } else if line.len() + 1 + element.len() < 70 {

ray-tracer/src/transforms.rs

@@ -189,4 +189,31 @@ mod tests {
         let p = Point::new(2., 3., 4.);
         assert_eq!(transform * p, Point::new(2., 3., 7.));
     }
+
+    #[test]
+    fn individual_transformations_are_applied_in_sequence() {
+        let p = Point::new(1., 0., 1.);
+        let rotation = rotation_x(PI / 2.);
+        let scale = scaling(5., 5., 5.);
+        let translate = translation(10., 5., 7.);
+
+        let p2 = rotation * p;
+        assert_eq!(p2, Point::new(1., -1., 0.));
+
+        let p3 = scale * p2;
+        assert_eq!(p3, Point::new(5., -5., 0.));
+
+        let p4 = translate * p3;
+        assert_eq!(p4, Point::new(15., 0., 7.));
+    }
+
+    #[test]
+    fn chained_translations() {
+        let p = Point::new(1., 0., 1.);
+        let rotation = rotation_x(PI / 2.);
+        let scale = scaling(5., 5., 5.);
+        let translate = translation(10., 5., 7.);
+        let tr = translate * scale * rotation;
+        assert_eq!(tr * p, Point::new(15., 0., 7.));
+    }
 }

ray-tracer/src/types/canvas.rs

@@ -29,7 +29,7 @@ impl Canvas {
         &self.pixels[self.addr(y, x)]
     }
 
-    pub fn pixel_mut<'a>(&'a mut self, x: usize, y: usize) -> &'a mut Color {
+    pub fn pixel_mut(&mut self, x: usize, y: usize) -> &mut Color {
         let addr = self.addr(y, x);
         &mut self.pixels[addr]
     }

ray-tracer/src/types/matrix.rs

@@ -1,4 +1,6 @@
-use crate::types::{eq_f64, Tuple, Point, Vector};
+use std::cmp::Ordering;
+
+use crate::types::{eq_f64, Point, Tuple, Vector};
 
 #[derive(Clone, Debug)]
 pub struct Matrix {
@@ -27,7 +29,7 @@ impl Matrix {
         self.values[self.addr(row, column)]
     }
 
-    pub fn cell_mut<'a>(&'a mut self, row: usize, column: usize) -> &'a mut f64 {
+    pub fn cell_mut(&mut self, row: usize, column: usize) -> &mut f64 {
         let addr = self.addr(row, column);
         &mut self.values[addr]
     }
@@ -92,19 +94,15 @@ impl Matrix {
 
         for r in 0..self.size {
             for c in 0..self.size {
-                let dest_r = if r < row {
-                    r
-                } else if r > row {
-                    r - 1
-                } else {
-                    continue;
+                let dest_r = match r.cmp(&row) {
+                    Ordering::Less => r,
+                    Ordering::Greater => r - 1,
+                    Ordering::Equal => continue,
                 };
-                let dest_c = if c < column {
-                    c
-                } else if c > column {
-                    c - 1
-                } else {
-                    continue;
+                let dest_c = match c.cmp(&column) {
+                    Ordering::Less => c,
+                    Ordering::Greater => c - 1,
+                    Ordering::Equal => continue,
                 };
                 *m.cell_mut(dest_r, dest_c) = self.cell(r, c);
             }
@@ -198,8 +196,8 @@ impl std::ops::Mul<Tuple> for Matrix {
 
         let mut t = [0.; 4];
 
-        for row in 0..4 {
-            t[row] = self.cell(row, 0) * rside.0
+        for (row, item) in t.iter_mut().enumerate() {
+            *item = self.cell(row, 0) * rside.0
                 + self.cell(row, 1) * rside.1
                 + self.cell(row, 2) * rside.2
                 + self.cell(row, 3) * rside.3;

ray-tracer/src/types/tuple.rs

@@ -6,7 +6,7 @@ pub struct Tuple(
     pub f64, // y or green
     pub f64, // z or blue
     pub f64, // w, the flag which
-         // indicates point vs vec, or alpha
+             // indicates point vs vec, or alpha
 );
 
 impl Tuple {
@@ -44,12 +44,7 @@ impl std::ops::Sub for Tuple {
 impl std::ops::Neg for Tuple {
     type Output = Tuple;
     fn neg(self) -> Self::Output {
-        return Self::Output {
-            0: -self.0,
-            1: -self.1,
-            2: -self.2,
-            3: -self.3,
-        };
+        Tuple(-self.0, -self.1, -self.2, -self.3)
     }
 }