From 78d5a4804207cadf937f3144c17505fc19d13d75 Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Wed, 3 Aug 2022 20:34:03 +0200
Subject: [PATCH 1/2] Use `Scalar` as epsilon type for `AbsDiffEq` impls

---
 crates/fj-math/src/line.rs      | 12 ++++++++----
 crates/fj-math/src/point.rs     |  2 +-
 crates/fj-math/src/scalar.rs    |  6 +++---
 crates/fj-math/src/transform.rs |  2 +-
 crates/fj-math/src/vector.rs    |  2 +-
 5 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/crates/fj-math/src/line.rs b/crates/fj-math/src/line.rs
index 303989541..4bfed5413 100644
--- a/crates/fj-math/src/line.rs
+++ b/crates/fj-math/src/line.rs
@@ -136,10 +136,10 @@ impl<const D: usize> Line<D> {
 }
 
 impl<const D: usize> approx::AbsDiffEq for Line<D> {
-    type Epsilon = <f64 as approx::AbsDiffEq>::Epsilon;
+    type Epsilon = <Scalar as approx::AbsDiffEq>::Epsilon;
 
     fn default_epsilon() -> Self::Epsilon {
-        f64::default_epsilon()
+        Scalar::default_epsilon()
     }
 
     fn abs_diff_eq(&self, other: &Self, epsilon: Self::Epsilon) -> bool {
@@ -152,7 +152,7 @@ impl<const D: usize> approx::AbsDiffEq for Line<D> {
 mod tests {
     use approx::assert_abs_diff_eq;
 
-    use crate::{Point, Vector};
+    use crate::{Point, Scalar, Vector};
 
     use super::Line;
 
@@ -185,7 +185,11 @@ mod tests {
             let point = line.point_from_line_coords([t]);
             let t_result = line.point_to_line_coords(point);
 
-            assert_abs_diff_eq!(Point::from([t]), t_result, epsilon = 1e-8);
+            assert_abs_diff_eq!(
+                Point::from([t]),
+                t_result,
+                epsilon = Scalar::from(1e-8)
+            );
         }
     }
 }
diff --git a/crates/fj-math/src/point.rs b/crates/fj-math/src/point.rs
index 8502e8963..a8ad46785 100644
--- a/crates/fj-math/src/point.rs
+++ b/crates/fj-math/src/point.rs
@@ -209,7 +209,7 @@ impl<const D: usize> approx::AbsDiffEq for Point<D> {
     type Epsilon = <Vector<D> as approx::AbsDiffEq>::Epsilon;
 
     fn default_epsilon() -> Self::Epsilon {
-        f64::default_epsilon()
+        Scalar::default_epsilon()
     }
 
     fn abs_diff_eq(&self, other: &Self, epsilon: Self::Epsilon) -> bool {
diff --git a/crates/fj-math/src/scalar.rs b/crates/fj-math/src/scalar.rs
index 2036bfce0..96a258638 100644
--- a/crates/fj-math/src/scalar.rs
+++ b/crates/fj-math/src/scalar.rs
@@ -519,13 +519,13 @@ impl fmt::Display for Scalar {
 }
 
 impl approx::AbsDiffEq for Scalar {
-    type Epsilon = <f64 as approx::AbsDiffEq>::Epsilon;
+    type Epsilon = Self;
 
     fn default_epsilon() -> Self::Epsilon {
-        f64::default_epsilon()
+        f64::default_epsilon().into()
     }
 
     fn abs_diff_eq(&self, other: &Self, epsilon: Self::Epsilon) -> bool {
-        self.0.abs_diff_eq(&other.0, epsilon)
+        self.0.abs_diff_eq(&other.0, epsilon.0)
     }
 }
diff --git a/crates/fj-math/src/transform.rs b/crates/fj-math/src/transform.rs
index da95ea7f9..279e29ee6 100644
--- a/crates/fj-math/src/transform.rs
+++ b/crates/fj-math/src/transform.rs
@@ -178,7 +178,7 @@ mod tests {
                 Point::from([1., 3., 3.]),
                 Vector::from([-1., 0., 0.]),
             ),
-            epsilon = 1e-8,
+            epsilon = Scalar::from(1e-8),
         );
     }
 
diff --git a/crates/fj-math/src/vector.rs b/crates/fj-math/src/vector.rs
index 2b99f4055..3a3c88f25 100644
--- a/crates/fj-math/src/vector.rs
+++ b/crates/fj-math/src/vector.rs
@@ -326,7 +326,7 @@ impl<const D: usize> approx::AbsDiffEq for Vector<D> {
     type Epsilon = <Scalar as approx::AbsDiffEq>::Epsilon;
 
     fn default_epsilon() -> Self::Epsilon {
-        f64::default_epsilon()
+        Scalar::default_epsilon()
     }
 
     fn abs_diff_eq(&self, other: &Self, epsilon: Self::Epsilon) -> bool {

From 2923d235fd584c2841bf71e9e2bcd6dea6f881bc Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Wed, 3 Aug 2022 20:36:03 +0200
Subject: [PATCH 2/2] Implement `AbsDiffEq` for `Circle`

---
 crates/fj-math/src/circle.rs | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/crates/fj-math/src/circle.rs b/crates/fj-math/src/circle.rs
index 29212cf90..7ae63c8ba 100644
--- a/crates/fj-math/src/circle.rs
+++ b/crates/fj-math/src/circle.rs
@@ -77,6 +77,20 @@ impl<const D: usize> Circle<D> {
     }
 }
 
+impl<const D: usize> approx::AbsDiffEq for Circle<D> {
+    type Epsilon = <Scalar as approx::AbsDiffEq>::Epsilon;
+
+    fn default_epsilon() -> Self::Epsilon {
+        Scalar::default_epsilon()
+    }
+
+    fn abs_diff_eq(&self, other: &Self, epsilon: Self::Epsilon) -> bool {
+        self.center.abs_diff_eq(&other.center, epsilon)
+            && self.a.abs_diff_eq(&other.a, epsilon)
+            && self.b.abs_diff_eq(&other.b, epsilon)
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use std::f64::consts::{FRAC_PI_2, PI};