5 files changed, 110 insertions, 15 deletions
diff --git a/src/lerp.rs b/src/lerp.rs
index 7c4994c..8a33e8f 100644
--- a/src/lerp.rs
+++ b/src/lerp.rs
@@ -1,4 +1,5 @@
-use crate::poly::{self, Number, Poly};
+use crate::number::Number;
+use crate::poly::{self, Poly};
 
 pub enum Lerp {
     Node(Box<Lerp>, Box<Lerp>),
diff --git a/src/main.rs b/src/main.rs
index 8c23d3e..e5e4112 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,8 +1,9 @@
 mod poly;
+mod number;
 mod lerp;
 
-use crate::poly::Number;
-use crate::lerp::Lerp;
+use number::Number;
+use lerp::Lerp;
 
 use std::thread;
 use std::time::Duration;
@@ -13,10 +14,12 @@ use sdl2::keyboard::Keycode;
 use sdl2::rect::Rect;
 
 fn main() {
-    let a = Lerp::new(vec![100.0, 200.0, 300.0, 500.0]);
-    let b = Lerp::new(vec![400.0, 140.0, 500.0, 300.0]);
-    let pa = lerp::lp(a);
-    let pb = lerp::lp(b);
+    //let a = Lerp::new(vec![2.0, -2.0, 2.0]);
+    //let b = Lerp::new(vec![-1.0, 1.0, 2.0]);
+    //let pa = lerp::lp(a);
+    //let pb = lerp::lp(b);
+    let pa = vec![1.0, 5.0, -2.0];
+    let pb = vec![5.0, -4.0, 0.0];
     let p = poly::gcd(&pa, &pb);
 
     let sdl_context = sdl2::init().unwrap();
@@ -43,16 +46,20 @@ fn main() {
             }
         }
 
-        for t in 0..800 {
-            let x = poly::eval_poly(&pa, t as Number / 800.0);
-            let y = poly::eval_poly(&pb, t as Number / 800.0);
-            let z = poly::eval_poly(&p,  t as Number / 800.0);
+        let s = -600.0 / 10.0;
+        let k = 600.0 / 2.0;
+        for t in -800..800 {
+            let x = k + s * poly::eval_poly(&pa, t as Number / 100.0);
+            let y = k + s * poly::eval_poly(&pb, t as Number / 100.0);
+            let z = k + s * poly::eval_poly(&p,  t as Number / 100.0);
             canvas.set_draw_color(Color::RGB(180, 20, 20));
-            canvas.fill_rect(Rect::new(t, x as i32, 5, 5)).unwrap();
+            canvas.fill_rect(Rect::new(400 + t, x as i32, 5, 5)).unwrap();
             canvas.set_draw_color(Color::RGB(20, 180, 20));
-            canvas.fill_rect(Rect::new(t, y as i32, 5, 5)).unwrap();
+            canvas.fill_rect(Rect::new(400 + t, y as i32, 5, 5)).unwrap();
             canvas.set_draw_color(Color::RGB(20, 20, 180));
-            canvas.fill_rect(Rect::new(t, z as i32, 5, 5)).unwrap();
+            canvas.fill_rect(Rect::new(400 + t, z as i32, 2, 2)).unwrap();
+            canvas.set_draw_color(Color::RGB(255, 0, 0));
+            canvas.fill_rect(Rect::new(400 + t, k as i32, 2, 2)).unwrap();
         }
 
         canvas.present();
diff --git a/src/number.rs b/src/number.rs
new file mode 100644
index 0000000..cd5d47f
--- /dev/null
+++ b/src/number.rs
@@ -0,0 +1 @@
+pub type Number = f32;
diff --git a/src/poly.rs b/src/poly.rs
index 2128d38..34444b3 100644
--- a/src/poly.rs
+++ b/src/poly.rs
@@ -1,6 +1,53 @@
+mod iter;
+
+use crate::number::Number;
+use iter::Iter;
+use std::cmp;
 use std::cmp::Ordering;
+use std::ops::{Add, Sub};
+use std::iter::{Zip, Take};
+
+#[derive(PartialEq, Debug)]
+pub struct P(Vec<Number>);
+
+impl P {
+    fn degree(&self) -> usize {
+        let mut i = self.0.len() - 1;
+        while self.0[i] == 0.0 && i > 0 {
+            i -= 1;
+        }
+        i
+    }
+
+    fn iter(&self) -> Iter {
+        Iter::new(self.0.clone())
+    }
+
+    fn zip(&self, other: &Self) -> Zip<Take<Iter>, Take<Iter>> {
+        let deg = cmp::max(self.degree(), other.degree()) + 1;
+        let a = self.iter().take(deg);
+        let b = other.iter().take(deg);
+        a.zip(b)
+    }
+}
+
+impl Add for &P {
+    type Output = P;
+
+    fn add(self, other: Self) -> P {
+        P(self.zip(other).map(|(x, y)| {x + y}).collect())
+    }
+}
+
+impl Sub for &P {
+    type Output = P;
+
+    fn sub(self, other: Self) -> P {
+        P(self.zip(other).map(|(x, y)| {x - y}).collect())
+    }
+}
 
-pub type Number = f32;
+//****************************REFACTORING************************************
 
 pub type Poly = Vec<Number>;
 
@@ -88,6 +135,20 @@ mod tests {
     use super::*;
 
     #[test]
+    fn add_test() {
+        let a = P(vec![1.0]);
+        let b = P(vec![0.0, 0.0, 0.0, 1.0]);
+        assert_eq!(&a + &b, P(vec![1.0, 0.0, 0.0, 1.0]));
+    }
+
+    #[test]
+    fn sub_test() {
+        let a = P(vec![1.0, 2.0, 3.0]);
+        let b = P(vec![1.0]);
+        assert_eq!(&a - &b, P(vec![0.0, 2.0, 3.0]));
+    }
+
+    #[test]
     fn poly_is_zero() {
         let p = vec![0.0; 5];
         assert_eq!(is_zero(&p), true);
diff --git a/src/poly/iter.rs b/src/poly/iter.rs
new file mode 100644
index 0000000..26c5989
--- /dev/null
+++ b/src/poly/iter.rs
@@ -0,0 +1,25 @@
+use crate::number::Number;
+
+pub struct Iter {
+    index: usize,
+    data: Vec<Number>
+}
+
+impl Iter {
+    pub fn new(data: Vec<Number>) -> Iter {
+        Iter { index: 0, data }
+    }
+}
+
+impl Iterator for Iter {
+    type Item = Number;
+
+    fn next(&mut self) -> Option<Number> {
+        self.index += 1;
+        if self.index <= self.data.len() {
+            Some(self.data[self.index - 1])
+        } else {
+            Some(0.0)
+        }
+    }
+}