From 727b1c2ee98d395429ec1e667279fc3f5fec3a5c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Juan=20Manuel=20Tom=C3=A1s?= <jtomas1815@gmail.com>
Date: Sun, 17 Jan 2021 17:51:07 -0300
Subject: Fix fragment shader bug on empty curves

---
 src/lerp.rs |  6 ++++--
 src/main.rs |  6 +++---
 src/poly.rs | 69 +------------------------------------------------------------
 3 files changed, 8 insertions(+), 73 deletions(-)

(limited to 'src')

diff --git a/src/lerp.rs b/src/lerp.rs
index 222671f..1501d0f 100644
--- a/src/lerp.rs
+++ b/src/lerp.rs
@@ -4,6 +4,7 @@ use crate::poly::Poly;
 pub enum Lerp {
     Node(Box<Lerp>, Box<Lerp>),
     Leaf(Number, Number),
+    Just(Number)
 }
 
 impl Lerp {
@@ -13,8 +14,8 @@ impl Lerp {
 
     fn new_s(v: &[Number]) -> Box<Lerp> {
         match v.len() {
-            0 => Box::new(Lerp::Leaf(0.0, 0.0)),
-            1 => Box::new(Lerp::Leaf(v[0], v[0])),
+            0 => Box::new(Lerp::Just(0.0)),
+            1 => Box::new(Lerp::Just(v[0])),
             2 => Box::new(Lerp::Leaf(v[0], v[1])),
             _ => Box::new(Lerp::Node(
                 Lerp::new_s(&v[0..v.len() - 1]),
@@ -26,6 +27,7 @@ impl Lerp {
 
 pub fn lp(l: Box<Lerp>) -> Poly {
     match *l {
+        Lerp::Just(a) => Poly::new(vec![a]),
         Lerp::Leaf(a, b) => Poly::new(vec![a, b - a]),
         Lerp::Node(a, b) => {
             let a = lp(a);
diff --git a/src/main.rs b/src/main.rs
index 242a1ef..9f9ad9f 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -26,8 +26,8 @@ fn shader_from_source(source: &CStr, shader_type: GLenum) -> GLuint {
 }
 
 fn main() {
-    let a = lerp::lp(Lerp::new(vec![100.0, 200.0, 800.0, 400.0, 800.0, 100.0]));
-    let b = lerp::lp(Lerp::new(vec![100.0, 550.0, 500.0, 300.0, 200.0, 800.0]));
+    let a = lerp::lp(Lerp::new(vec![200.0, 500.0, 500.0]));
+    let b = lerp::lp(Lerp::new(vec![200.0, 500.0, 200.0]));
 
     let sdl_context = sdl2::init().unwrap();
     let video_subsystem = sdl_context.video().unwrap();
@@ -110,7 +110,7 @@ float inside(vec2 pos) {{
     }}
     t = step;
   }}
-  return 1 - pow(closest / thr, 2);
+  return 1 - closest / thr;
 }}
 
 void main() {{
diff --git a/src/poly.rs b/src/poly.rs
index 34df7a0..bae3a15 100644
--- a/src/poly.rs
+++ b/src/poly.rs
@@ -3,7 +3,7 @@ mod iter;
 use crate::number::Number;
 use iter::Iter;
 use std::fmt;
-use std::ops::{Add, Div, Mul, Sub};
+use std::ops::{Add, Mul, Sub};
 
 #[derive(PartialEq, Debug, Clone)]
 pub struct Poly {
@@ -34,22 +34,10 @@ impl Poly {
         self.degree
     }
 
-    fn lc(&self) -> Number {
-        self.data[self.degree()]
-    }
-
     fn iter(&self) -> Iter {
         Iter::new(self.data.clone(), self.degree())
     }
 
-    pub fn eval(&self, n: Number) -> Number {
-        let mut r = 0.0;
-        for i in 0..self.data.len() {
-            r += self.data[i] * n.powi(i as i32);
-        }
-        r
-    }
-
     fn is_zero(&self) -> bool {
         for i in 0..self.data.len() {
             if self.data[i] != 0.0 {
@@ -95,21 +83,6 @@ impl Mul for &Poly {
     }
 }
 
-impl Div for &Poly {
-    type Output = (Poly, Poly);
-
-    fn div(self, divisor: Self) -> (Poly, Poly) {
-        let mut q = Poly::new(vec![0.0]);
-        let mut r = self.clone();
-        while !r.is_zero() && r.degree() >= divisor.degree() {
-            let s = Poly::mono(r.degree() - divisor.degree(), r.lc() / divisor.lc());
-            q = &q + &s;
-            r = &r - &(&s * divisor);
-        }
-        (q, r)
-    }
-}
-
 impl fmt::Display for &Poly {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         let mut s = String::new();
@@ -127,39 +100,6 @@ impl fmt::Display for &Poly {
 mod tests {
     use super::*;
 
-    #[test]
-    fn derivative_test() {
-        let p = Poly::new(vec![1.0, 2.0, 3.0, 4.0, 5.0]);
-        assert_eq!(derivative(&p), Poly::new(vec![2.0, 6.0, 12.0, 20.0]));
-    }
-
-    #[test]
-    fn div_equal() {
-        let a = Poly::new(vec![6.0, 7.0, 1.0]);
-        let b = Poly::new(vec![-6.0, -5.0, 1.0]);
-        assert_eq!(
-            &a / &b,
-            (Poly::new(vec![1.0]), Poly::new(vec![12.0, 12.0, 0.0]))
-        );
-    }
-
-    #[test]
-    fn div_greater() {
-        let a = Poly::new(vec![-6.0, -5.0, 1.0]);
-        let b = Poly::new(vec![12.0, 12.0]);
-        assert_eq!(
-            &a / &b,
-            (Poly::new(vec![-0.5, 1.0 / 12.0]), Poly::new(vec![0.0, 0.0]))
-        );
-    }
-
-    #[test]
-    fn div_less() {
-        let a = Poly::new(vec![12.0, 12.0]);
-        let b = Poly::new(vec![-6.0, -5.0, 1.0]);
-        assert_eq!(&a / &b, (Poly::new(vec![0.0]), a));
-    }
-
     #[test]
     fn mul_test() {
         let a = Poly::new(vec![1.0, 2.0, 3.0]);
@@ -204,11 +144,4 @@ mod tests {
         let p = Poly::new(vec![0.0; 6]);
         assert_eq!(p.degree(), 0);
     }
-
-    #[test]
-    fn gcd_test() {
-        let a = Poly::new(vec![2.0, -8.0, 8.0]);
-        let b = Poly::new(vec![-1.0, 4.0, -1.0]);
-        assert_eq!(gcd(&a, &b), Poly::new(vec![-0.0625, 0.0]));
-    }
 }
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