From bb63d86a8c3e7db0f48b2b7cd169d118dd943f62 Mon Sep 17 00:00:00 2001
From: Alain Zscheile <fogti+devel@ytrizja.de>
Date: Fri, 8 Dec 2023 00:29:32 +0100
Subject: [PATCH] spiral: use cosine for dyanmic scale

---
 src/ex.rs | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/ex.rs b/src/ex.rs
index 84506f9..7605438 100644
--- a/src/ex.rs
+++ b/src/ex.rs
@@ -143,9 +143,8 @@ pub fn cassini_astroid(ca: f64, cc: f64, aa: f64) -> impl Fn(f64) -> [f64; 2] {
 pub fn spiral(k: u32) -> impl Fn(f64) -> [f64; 2] {
     let x2pi = (k as f64) * core::f64::consts::TAU;
     move |t: f64| {
-        let tstretch = t - 0.5;
-        let tstretch = tstretch * tstretch;
+        let ttcos = (t * core::f64::consts::TAU).cos();
         let (ttxsin, ttxcos) = (t * x2pi).sin_cos();
-        [tstretch * ttxcos, tstretch * ttxsin]
+        [ttcos * ttxcos, ttcos * ttxsin]
     }
 }