From 28289869c77cad2c1d997107a6a1cb3a8f0a251f Mon Sep 17 00:00:00 2001
From: hpinkos <hannah@cesium.com>
Date: Tue, 5 Jan 2021 17:14:51 -0500
Subject: [PATCH 1/2] add Cartesian2.cross

---
 Source/Core/Cartesian2.js    | 16 ++++++++++++++++
 Specs/Core/Cartesian2Spec.js |  8 ++++++++
 2 files changed, 24 insertions(+)

diff --git a/Source/Core/Cartesian2.js b/Source/Core/Cartesian2.js
index 64a5ca0422bf..1f5a30d42855 100644
--- a/Source/Core/Cartesian2.js
+++ b/Source/Core/Cartesian2.js
@@ -406,6 +406,22 @@ Cartesian2.dot = function (left, right) {
   return left.x * right.x + left.y * right.y;
 };
 
+/**
+ * Computes the cross (outer) product of two Cartesians.
+ *
+ * @param {Cartesian2} left The first Cartesian.
+ * @param {Cartesian2} right The second Cartesian.
+ * @returns {Number} The cross product.
+ */
+Cartesian2.cross = function (left, right) {
+  //>>includeStart('debug', pragmas.debug);
+  Check.typeOf.object("left", left);
+  Check.typeOf.object("right", right);
+  //>>includeEnd('debug');
+
+  return left.x * right.y - left.y * right.x;
+};
+
 /**
  * Computes the componentwise product of two Cartesians.
  *
diff --git a/Specs/Core/Cartesian2Spec.js b/Specs/Core/Cartesian2Spec.js
index 591d66f99f5d..305748e49161 100644
--- a/Specs/Core/Cartesian2Spec.js
+++ b/Specs/Core/Cartesian2Spec.js
@@ -402,6 +402,14 @@ describe("Core/Cartesian2", function () {
     expect(result).toEqual(expectedResult);
   });
 
+  it("cross", function () {
+    var left = new Cartesian2(0.0, 1.0);
+    var right = new Cartesian2(1.0, 0.0);
+    var expectedResult = -1.0;
+    var result = Cartesian2.cross(left, right);
+    expect(result).toEqual(expectedResult);
+  });
+
   it("add works with a result parameter", function () {
     var left = new Cartesian2(2.0, 3.0);
     var right = new Cartesian2(4.0, 5.0);

From b86c97d6ed31b102ac7955c82afdd6e25b5069dc Mon Sep 17 00:00:00 2001
From: Hannah <hannah@cesium.com>
Date: Thu, 7 Jan 2021 12:51:08 -0500
Subject: [PATCH 2/2] Update Cartesian2.js

---
 Source/Core/Cartesian2.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Source/Core/Cartesian2.js b/Source/Core/Cartesian2.js
index 1f5a30d42855..986b109eb4f4 100644
--- a/Source/Core/Cartesian2.js
+++ b/Source/Core/Cartesian2.js
@@ -407,7 +407,7 @@ Cartesian2.dot = function (left, right) {
 };
 
 /**
- * Computes the cross (outer) product of two Cartesians.
+ * Computes the magnitude of the cross product that would result from implicitly setting the Z coordinate of the input vectors to 0
  *
  * @param {Cartesian2} left The first Cartesian.
  * @param {Cartesian2} right The second Cartesian.