Created a Projectile and allowed it to be operated on by wind and gravity

Cargo.lock

@@ -1,5 +1,39 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+[[package]]
+name = "approx"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3f2a05fd1bd10b2527e20a2cd32d8873d115b8b39fe219ee25f42a8aca6ba278"
+dependencies = [
+ "num-traits",
+]
+
+[[package]]
+name = "autocfg"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cdb031dd78e28731d87d56cc8ffef4a8f36ca26c38fe2de700543e627f8a464a"
+
+[[package]]
+name = "num-traits"
+version = "0.2.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9a64b1ec5cda2586e284722486d802acf1f7dbdc623e2bfc57e65ca1cd099290"
+dependencies = [
+ "autocfg",
+]
+
+[[package]]
+name = "structs"
+version = "0.1.0"
+dependencies = [
+ "approx",
+]
+
 [[package]]
 name = "tuples"
 version = "0.1.0"
+dependencies = [
+ "structs",
+]

Cargo.toml

@@ -7,3 +7,4 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+structs = { path = "structs" }

src/main.rs

@@ -1,3 +1,71 @@
-fn main() {
-    println!("Hello, world!");
+use structs::Tuple;
+
+use std::fmt;
+
+#[derive(Debug)]
+struct Environment {
+    gravity: Tuple,
+    wind: Tuple,
+}
+
+#[derive(Debug, Clone, Copy)]
+struct Projectile {
+    position: Tuple,
+    velocity: Tuple,
+}
+
+impl Projectile {
+
+    fn new(position: Tuple, velocity: Tuple) -> Projectile {
+        if !position.is_point() {
+            panic!("position can not be a vector");
+        }
+
+        if !velocity.is_vector() {
+            panic!("velocity can not be point");
+        }
+
+        Projectile {
+            position: position,
+            velocity: velocity,
+        }
+    }
+}
+
+impl Projectile {
+    fn tick(&mut self, env: &Environment) {
+        self.position = self.position + self.velocity;
+        self.velocity = env.wind + env.gravity;
+    }
+}
+
+impl fmt::Display for Projectile {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "pos: {}, vel {}", self.position, self.velocity)
+    }
+}
+
+fn init_env() -> Environment {
+    Environment {
+            gravity: Tuple::vector(0.0, 0.0, -0.98),
+            wind: Tuple::vector(0.0, 0.0, 0.0),
+    }
+}
+
+fn main() {
+    let env = init_env();
+
+    let mut ball = Projectile::new(
+        Tuple::point(0.0, 0.0, 1.0),
+        Tuple::vector(1.0, 0.0, 0.0),
+    );
+
+    let mut tick = 0;
+    println!("tick {} the ball {}", tick, ball);
+    while ball.position.z() > 0.0 {
+        ball.tick(&env);
+
+        println!("tick {} the ball {}", tick, ball);
+        tick += 1;
+    }
 }

structs/src/lib.rs

@@ -1,10 +1,11 @@
 #[macro_use]
 extern crate approx;
 
+use std::fmt;
 use std::ops;
 
-#[derive(Debug)]
-struct Tuple {
+#[derive(Debug, Copy, Clone)]
+pub struct Tuple {
     x: f32,
     y: f32,
     z: f32,
@@ -12,7 +13,7 @@ struct Tuple {
 }
 
 impl Tuple {
-    fn new(x: f32, y: f32, z: f32, w: f32) -> Tuple {
+    pub fn new(x: f32, y: f32, z: f32, w: f32) -> Tuple {
         Tuple {
             x,
             y,
@@ -22,7 +23,7 @@ impl Tuple {
     }
 
 
-    fn point(x: f32, y: f32, z: f32) -> Tuple {
+    pub fn point(x: f32, y: f32, z: f32) -> Tuple {
         Tuple {
             x,
             y,
@@ -31,7 +32,7 @@ impl Tuple {
         }
     }
 
-    fn vector(x: f32, y: f32, z: f32) -> Tuple {
+    pub fn vector(x: f32, y: f32, z: f32) -> Tuple {
         Tuple {
             x,
             y,
@@ -42,27 +43,27 @@ impl Tuple {
 }
 
 impl Tuple {
-    fn x(&self) -> f32 {
+    pub fn x(&self) -> f32 {
         self.x
     }
 
-    fn y(&self) -> f32 {
+    pub fn y(&self) -> f32 {
         self.y
     }
 
-    fn z(&self) -> f32 {
+    pub fn z(&self) -> f32 {
         self.z
     }
 
-    fn is_point(&self) -> bool {
+    pub fn is_point(&self) -> bool {
         self.w == 1.0
     }
 
-    fn is_vector(&self) -> bool {
+    pub fn is_vector(&self) -> bool {
         self.w == 0.0
     }
 
-    fn magnitude(&self) -> f32 {
+    pub fn magnitude(&self) -> f32 {
         (
             (self.x * self.x) +
             (self.y * self.y) +
@@ -71,7 +72,7 @@ impl Tuple {
         ).sqrt()
     }
 
-    fn normalize(&self) -> Tuple {
+    pub fn normalize(&self) -> Tuple {
         let m = self.magnitude();
         Tuple::new(
             self.x / m,
@@ -81,14 +82,14 @@ impl Tuple {
         )
     }
 
-    fn dot(&self, rhs: &Tuple) -> f32 {
+    pub fn dot(&self, rhs: &Tuple) -> f32 {
         self.x * rhs.x +
             self.y * rhs.y +
             self.z * rhs.z +
             self.w * rhs.w
     }
 
-    fn cross(&self, rhs: &Tuple) -> Tuple {
+    pub fn cross(&self, rhs: &Tuple) -> Tuple {
         Tuple::vector(
             self.y * rhs.z - self.z * rhs.y,
             self.z * rhs.x - self.x * rhs.z,
@@ -97,6 +98,12 @@ impl Tuple {
     }
 }
 
+impl fmt::Display for Tuple {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "({}, {}, {}) {}", self.x, self.y, self.z, if self.is_point() { "p" } else { "v" } )
+    }
+}
+
 impl PartialEq for Tuple {
     fn eq(&self, _rhs: &Self) -> bool {
         relative_eq!(self.x, _rhs.x)
@@ -184,6 +191,7 @@ impl ops::Div<f32> for Tuple {
     }
 }
 
+
 #[cfg(test)]
 mod tests {
     use super::*;