+Spiral1D

src/ex.rs

@@ -12,7 +12,7 @@ pub fn circle_deriv(t: f64) -> [f64; 2] {
     use core::f64::consts::TAU;
     let tt2pi = t * TAU;
     let (ttsin, ttcos) = tt2pi.sin_cos();
-    [- TAU * ttsin, TAU * ttcos]
+    [-TAU * ttsin, TAU * ttcos]
 }
 
 pub fn ellipse(a: f64, b: f64) -> impl Fn(f64) -> [f64; 2] {
@@ -50,11 +50,7 @@ pub fn intersect_8pp(t: f64) -> [f64; 2] {
         [newx, x8p[1]]
     } else if (t < 0.0625) || (t >= 0.9375) {
         // /
-        let tx = sqrt2_16 * if afterh {
-            t - 1.0
-        } else {
-            t
-        };
+        let tx = sqrt2_16 * if afterh { t - 1.0 } else { t };
         [tx, -tx]
     } else {
         // \
@@ -107,8 +103,8 @@ pub fn cassini_oval(a: f64, c: f64) -> impl Fn(f64) -> [f64; 2] {
         let (ttsin, ttcos) = tt2pi.sin_cos();
         let denom = c2 + a2 * ttsin * ttsin;
         [
-          (c2 * cahyp * ttcos) / denom,
-          (cahyp * ttsin * (c4 - a4 * ttsin * ttsin).sqrt()) / denom,
+            (c2 * cahyp * ttcos) / denom,
+            (cahyp * ttsin * (c4 - a4 * ttsin * ttsin).sqrt()) / denom,
         ]
     }
 }
@@ -121,7 +117,10 @@ pub fn cassini_wobbly(a: f64, c: f64, wob: u32) -> impl Fn(f64) -> [f64; 2] {
         let ttx2pi = t * wobx;
         let (ttxsin, ttxcos) = (ttx2pi).sin_cos();
         let cas = cassini(t);
-        [ttxcos.mul_add(wobinv, cas[0]), ttxsin.mul_add(wobinv, cas[1])]
+        [
+            ttxcos.mul_add(wobinv, cas[0]),
+            ttxsin.mul_add(wobinv, cas[1]),
+        ]
     }
 }
 
@@ -148,3 +147,12 @@ pub fn spiral(k: u32) -> impl Fn(f64) -> [f64; 2] {
         [ttcos * ttxcos, ttcos * ttxsin]
     }
 }
+
+pub fn spiral_1d(k: u32) -> impl Fn(f64) -> [f64; 2] {
+    let x2pi = (k as f64) * core::f64::consts::TAU;
+    move |t: f64| {
+        let ttcos = (t * core::f64::consts::TAU).cos();
+        let ttxsin = (t * x2pi).sin();
+        [ttcos, ttxsin]
+    }
+}

src/lib.rs

@@ -18,6 +18,7 @@ pub enum SelectExample {
     Lemniskate { a: f64 },
 
     Spiral { k: u32 },
+    Spiral1D { k: u32 },
 
     Circle,
     Intersect8,
@@ -44,7 +45,11 @@ impl SelectExample {
             Self::Lemniskate { a } => {
                 *a += l;
             }
-            Self::Spiral { .. } | Self::Circle | Self::Intersect8 | Self::Intersect8pp => {
+            Self::Spiral { .. }
+            | Self::Spiral1D { .. }
+            | Self::Circle
+            | Self::Intersect8
+            | Self::Intersect8pp => {
                 panic!("offsetting not supported for this example")
             }
         }
@@ -58,10 +63,11 @@ impl SelectExample {
             Self::CassiniAstroidTsq { ca, cc, aa } => {
                 let x = ex::cassini_astroid(ca, cc, aa);
                 Box::new(move |t: f64| x(t * t))
-            },
+            }
             Self::Ellipse { a, b } => Box::new(ex::ellipse(a, b)),
             Self::Lemniskate { a } => Box::new(move |t: f64| ex::lemniskate(t, a)),
             Self::Spiral { k } => Box::new(ex::spiral(k)),
+            Self::Spiral1D { k } => Box::new(ex::spiral_1d(k)),
             Self::Circle => Box::new(ex::circle),
             Self::Intersect8 => Box::new(ex::intersect_eight),
             Self::Intersect8pp => Box::new(ex::intersect_8pp),