Added distance to Cartesian2 and Cartesian4 for consistency

Source/Core/Cartesian2.js

@@ -188,6 +188,32 @@ define([
         return Math.sqrt(Cartesian2.magnitudeSquared(cartesian));
     };
 
+    var distanceScratch = new Cartesian2();
+
+    /**
+     * Computes the distance between two points
+     * @memberof Cartesian2
+     *
+     * @param {Cartesian2} left The first point to compute the distance from.
+     * @param {Cartesian2} right The second point to compute the distance to.
+     *
+     * @return {Number} The distance between two points.
+     *
+     * @exception {DeveloperError} left and right are required.
+     *
+     * @example
+     * // Returns 1.0
+     * var d = Cartesian2.distance(new Cartesian2(1.0, 0.0), new Cartesian2(2.0, 0.0));
+     */
+    Cartesian2.distance = function(left, right) {
+        if ((typeof left === 'undefined') || (typeof right === 'undefined')) {
+            throw new DeveloperError('left and right are required.');
+        }
+
+        Cartesian2.subtract(left, right, distanceScratch);
+        return Cartesian2.magnitude(distanceScratch);
+    };
+
     /**
      * Computes the normalized form of the supplied Cartesian.
      * @memberof Cartesian2

Source/Core/Cartesian4.js

@@ -179,6 +179,32 @@ define([
         return Math.sqrt(Cartesian4.magnitudeSquared(cartesian));
     };
 
+    var distanceScratch = new Cartesian4();
+
+    /**
+     * Computes the 4-space distance between two points
+     * @memberof Cartesian4
+     *
+     * @param {Cartesian4} left The first point to compute the distance from.
+     * @param {Cartesian4} right The second point to compute the distance to.
+     *
+     * @return {Number} The distance between two points.
+     *
+     * @exception {DeveloperError} left and right are required.
+     *
+     * @example
+     * // Returns 1.0
+     * var d = Cartesian4.distance(new Cartesian4(1.0, 0.0, 0.0, 0.0), new Cartesian4(2.0, 0.0, 0.0, 0.0));
+     */
+    Cartesian4.distance = function(left, right) {
+        if ((typeof left === 'undefined') || (typeof right === 'undefined')) {
+            throw new DeveloperError('left and right are required.');
+        }
+
+        Cartesian4.subtract(left, right, distanceScratch);
+        return Cartesian4.magnitude(distanceScratch);
+    };
+
     /**
      * Computes the normalized form of the supplied Cartesian.
      * @memberof Cartesian4

Specs/Core/Cartesian2Spec.js

@@ -107,6 +107,23 @@ defineSuite([
         expect(cartesian.magnitude()).toEqual(Math.sqrt(13.0));
     });
 
+    it('distance', function() {
+        var distance = Cartesian2.distance(new Cartesian2(1.0, 0.0), new Cartesian2(2.0, 0.0));
+        expect(distance).toEqual(1.0);
+    });
+
+    it('distance throws without left', function() {
+        expect(function() {
+            Cartesian2.distance();
+        }).toThrow();
+    });
+
+    it('distance throws without right', function() {
+        expect(function() {
+            Cartesian2.distance(Cartesian2.UNIT_X);
+        }).toThrow();
+    });
+
     it('normalize works without a result parameter', function() {
         var cartesian = new Cartesian2(2.0, 0.0);
         var expectedResult = new Cartesian2(1.0, 0.0);

Specs/Core/Cartesian4Spec.js

@@ -125,6 +125,23 @@ defineSuite([
         expect(cartesian.magnitude()).toEqual(Math.sqrt(86.0));
     });
 
+    it('distance', function() {
+        var distance = Cartesian4.distance(new Cartesian4(1.0, 0.0, 0.0, 0.0), new Cartesian4(2.0, 0.0, 0.0, 0.0));
+        expect(distance).toEqual(1.0);
+    });
+
+    it('distance throws without left', function() {
+        expect(function() {
+            Cartesian4.distance();
+        }).toThrow();
+    });
+
+    it('distance throws without right', function() {
+        expect(function() {
+            Cartesian4.distance(Cartesian4.UNIT_X);
+        }).toThrow();
+    });
+
     it('normalize works without a result parameter', function() {
         var cartesian = new Cartesian4(2.0, 0.0, 0.0, 0.0);
         var expectedResult = new Cartesian4(1.0, 0.0, 0.0, 0.0);