From 6af72f454a371a30071e9f22264f3d70a72acf4f Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Fri, 9 Sep 2022 11:44:10 +0200
Subject: [PATCH 1/2] Derive some traits for `Winding`

---
 crates/fj-math/src/triangle.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/crates/fj-math/src/triangle.rs b/crates/fj-math/src/triangle.rs
index 4d2612110..cbafd436e 100644
--- a/crates/fj-math/src/triangle.rs
+++ b/crates/fj-math/src/triangle.rs
@@ -114,6 +114,7 @@ pub struct NotATriangle<const D: usize> {
 }
 
 /// Winding direction of a triangle.
+#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash, Ord, PartialOrd)]
 pub enum Winding {
     /// Counter-clockwise
     Ccw,

From 3397f3ec72d98ed8d096e2dee27e73d1803c9a9e Mon Sep 17 00:00:00 2001
From: Hanno Braun <hanno@braun-odw.eu>
Date: Fri, 9 Sep 2022 12:50:53 +0200
Subject: [PATCH 2/2] Add `Vector<2>::cross`

---
 crates/fj-math/src/vector.rs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/crates/fj-math/src/vector.rs b/crates/fj-math/src/vector.rs
index 79a580d8f..9b2a59e44 100644
--- a/crates/fj-math/src/vector.rs
+++ b/crates/fj-math/src/vector.rs
@@ -127,6 +127,11 @@ impl Vector<2> {
     pub fn unit_v() -> Self {
         Vector::from([1., 0.])
     }
+
+    /// Compute the 2D cross product with another vector
+    pub fn cross(&self, other: &Self) -> Scalar {
+        (self.u * other.v) - (self.v * other.u)
+    }
 }
 
 impl Vector<3> {