vec2.dist

bpl · May 2, 2012 · 018e2c1 · 018e2c1
1 parent 4413cf6
commit 018e2c1
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diff --git a/gl-matrix.js b/gl-matrix.js
@@ -2355,6 +2355,22 @@
       return dest;
     };
 
+    /**
+     * Calculates the euclidian distance between two vec2
+     *
+     * Params:
+     * @param {vec2} vecA First vector
+     * @param {vec2} vecB Second vector
+     *
+     * @returns {number} Distance between vecA and vecB
+     */
+    vec2.dist = function (vecA, vecB) {
+        var x = vecB[0] - vecA[0],
+            y = vecB[1] - vecA[1];
+
+        return Math.sqrt(x*x + y*y);
+    };
+
     /*
      * Exports
      */

diff --git a/spec/javascripts/vec2_spec.js b/spec/javascripts/vec2_spec.js
@@ -3,6 +3,14 @@ describe("vec2", function() {
   var vecA, vecB, result;
   beforeEach(function() { vecA = [1, 2]; vecB = [3, 4]; dest = [0, 0]; });
 
+  describe("dist", function() {
+    beforeEach(function() { result = vec2.dist(vecA, vecB); });
+
+    it("should return dest", function() { expect(result).toBeEqualish(2.828427); });
+    it("should not modify vecA", function() { expect(vecA).toBeEqualish([1, 2]); });
+    it("should not modify vecB", function() { expect(vecB).toBeEqualish([3, 4]); });
+  });
+
   describe("scale", function() {
     describe("with dest vec2", function() {
       beforeEach(function() { result = vec2.scale(vecA, 0.5, dest); });