From ae8efcfae121d32447ad5c751d83b3527d13f75e Mon Sep 17 00:00:00 2001
From: T0mstone <realt0mstone@gmail.com>
Date: Thu, 26 May 2022 14:11:55 +0200
Subject: [PATCH 1/3] Improve the `Angle` type

* Add two new units
* Replace usage of `2 * PI` by `TAU`
* Replace angle-angle mul./div. with angle-scalar mul./div.
---
 crates/fj/src/angle.rs | 56 +++++++++++++++++++++++++++++++-----------
 1 file changed, 41 insertions(+), 15 deletions(-)

diff --git a/crates/fj/src/angle.rs b/crates/fj/src/angle.rs
index 5a6389d8d..e369fc6c8 100644
--- a/crates/fj/src/angle.rs
+++ b/crates/fj/src/angle.rs
@@ -1,4 +1,7 @@
-use std::f64::consts::PI;
+use std::f64::consts::{PI, TAU};
+
+// One gon in radians
+const GON_RAD: f64 = PI / 200.;
 
 /// An angle
 #[derive(Copy, Clone, Debug)]
@@ -19,6 +22,14 @@ impl Angle {
     pub fn from_deg(deg: f64) -> Self {
         Self::from_rad(deg.to_radians())
     }
+    /// Create a new angle specified in [revolutions](https://en.wikipedia.org/wiki/Turn_(angle))
+    pub fn from_rev(rev: f64) -> Self {
+        Self::from_rad(rev * TAU)
+    }
+    /// Create a new angle specified in [gon](https://en.wikipedia.org/wiki/Gradian)
+    pub fn from_gon(gon: f64) -> Self {
+        Self::from_rad(gon * GON_RAD)
+    }
     /// Retrieve value of angle as radians
     pub fn rad(&self) -> f64 {
         self.rad
@@ -27,12 +38,20 @@ impl Angle {
     pub fn deg(&self) -> f64 {
         self.rad.to_degrees()
     }
+    /// Retrieve value of angle as [revolutions](https://en.wikipedia.org/wiki/Turn_(angle))
+    pub fn rev(&self) -> f64 {
+        self.rad / TAU
+    }
+    /// Retrieve value of angle as [gon](https://en.wikipedia.org/wiki/Gradian)
+    pub fn gon(&self) -> f64 {
+        self.rad / GON_RAD
+    }
 
     // ensures that the angle is always 0 <= a < 2*pi
     fn wrap(rad: f64) -> f64 {
-        let modulo = rad % (2. * PI);
+        let modulo = rad % TAU;
         if modulo < 0. {
-            2. * PI + modulo
+            TAU + modulo
         } else {
             modulo
         }
@@ -72,30 +91,37 @@ impl std::ops::SubAssign for Angle {
     }
 }
 
-impl std::ops::Mul for Angle {
+impl std::ops::Mul<f64> for Angle {
+    type Output = Angle;
+    fn mul(self, rhs: f64) -> Self::Output {
+        Self::from_rad(self.rad * rhs)
+    }
+}
+
+impl std::ops::Mul<Angle> for f64 {
     type Output = Angle;
-    fn mul(self, rhs: Self) -> Self::Output {
-        Self::from_rad(self.rad * rhs.rad)
+    fn mul(self, rhs: Angle) -> Self::Output {
+        rhs * self
     }
 }
 
-impl std::ops::MulAssign for Angle {
-    fn mul_assign(&mut self, rhs: Self) {
-        self.rad *= rhs.rad;
+impl std::ops::MulAssign<f64> for Angle {
+    fn mul_assign(&mut self, rhs: f64) {
+        self.rad *= rhs;
         self.wrap_assign()
     }
 }
 
-impl std::ops::Div for Angle {
+impl std::ops::Div<f64> for Angle {
     type Output = Angle;
-    fn div(self, rhs: Self) -> Self::Output {
-        Self::from_rad(self.rad / rhs.rad)
+    fn div(self, rhs: f64) -> Self::Output {
+        Self::from_rad(self.rad / rhs)
     }
 }
 
-impl std::ops::DivAssign for Angle {
-    fn div_assign(&mut self, rhs: Self) {
-        self.rad /= rhs.rad;
+impl std::ops::DivAssign<f64> for Angle {
+    fn div_assign(&mut self, rhs: f64) {
+        self.rad /= rhs;
         self.wrap_assign()
     }
 }

From 0b46488a3bc3431a9f20a0906d3a389be2bbed07 Mon Sep 17 00:00:00 2001
From: T0mstone <realt0mstone@gmail.com>
Date: Thu, 26 May 2022 14:16:51 +0200
Subject: [PATCH 2/3] Reintroduce angle division

---
 crates/fj/src/angle.rs | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/crates/fj/src/angle.rs b/crates/fj/src/angle.rs
index e369fc6c8..880941c97 100644
--- a/crates/fj/src/angle.rs
+++ b/crates/fj/src/angle.rs
@@ -125,3 +125,10 @@ impl std::ops::DivAssign<f64> for Angle {
         self.wrap_assign()
     }
 }
+
+impl std::ops::Div for Angle {
+    type Output = f64;
+    fn div(self, rhs: Angle) -> Self::Output {
+        self.rad / rhs.rad
+    }
+}
\ No newline at end of file

From d2a25ccfd8bc2be2be15543aa1d54b6bc7a1415a Mon Sep 17 00:00:00 2001
From: T0mstone <realt0mstone@gmail.com>
Date: Thu, 26 May 2022 14:27:14 +0200
Subject: [PATCH 3/3] Add newline at the end of file

---
 crates/fj/src/angle.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/crates/fj/src/angle.rs b/crates/fj/src/angle.rs
index 880941c97..5345f9cec 100644
--- a/crates/fj/src/angle.rs
+++ b/crates/fj/src/angle.rs
@@ -131,4 +131,4 @@ impl std::ops::Div for Angle {
     fn div(self, rhs: Angle) -> Self::Output {
         self.rad / rhs.rad
     }
-}
\ No newline at end of file
+}