vec2.multiply, vec2.divide

bpl · May 2, 2012 · 19f3765 · 19f3765
1 parent be9d679
commit 19f3765
Showing 2 changed files with 70 additions and 0 deletions.
diff --git a/gl-matrix.js b/gl-matrix.js
@@ -2303,6 +2303,38 @@
       dest[1] = vecA[1] - vecB[1];
       return dest;
     };
+
+    /**
+     * Multiplies vecA with vecB. If dest is given, the result
+     * is stored there. Otherwise, the result is stored in vecB.
+     *
+     * @param {vec2} vecA the first operand
+     * @param {vec2} vecB the second operand
+     * @param {vec2} dest the optional receiving vector
+     * @returns {vec2} dest
+     */
+    vec2.multiply = function(vecA, vecB, dest) {
+      if (!dest) dest = vecB;
+      dest[0] = vecA[0] * vecB[0];
+      dest[1] = vecA[1] * vecB[1];
+      return dest;
+    };
+
+    /**
+     * Divides vecA by vecB. If dest is given, the result
+     * is stored there. Otherwise, the result is stored in vecB.
+     *
+     * @param {vec2} vecA the first operand
+     * @param {vec2} vecB the second operand
+     * @param {vec2} dest the optional receiving vector
+     * @returns {vec2} dest
+     */
+    vec2.divide = function(vecA, vecB, dest) {
+      if (!dest) dest = vecB;
+      dest[0] = vecA[0] / vecB[0];
+      dest[1] = vecA[1] / vecB[1];
+      return dest;
+    };
 
     /*
      * Exports

diff --git a/spec/javascripts/vec2_spec.js b/spec/javascripts/vec2_spec.js
@@ -41,6 +41,44 @@ describe("vec2", function() {
     });
   });
 
+  describe("multiply", function() {
+    describe("with dest vec2", function() {
+      beforeEach(function() { result = vec2.multiply(vecA, vecB, dest); });
+
+      it("should place values into dest", function() { expect(dest).toBeEqualish([3, 8]); });
+      it("should return dest", function() { expect(result).toBe(dest); });
+      it("should not modify vecA", function() { expect(vecA).toBeEqualish([1, 2]); });
+      it("should not modify vecB", function() { expect(vecB).toBeEqualish([3, 4]); });
+    });
+
+    describe("without dest vec2", function() {
+      beforeEach(function() { result = vec2.multiply(vecA, vecB); });
+
+      it("should place values into vecB", function() { expect(vecB).toBeEqualish([3, 8]); });
+      it("should return vecB", function() { expect(result).toBe(vecB); });
+      it("should not modify vecA", function() { expect(vecA).toBeEqualish([1, 2]); });
+    });
+  });
+
+  describe("divide", function() {
+    describe("with dest vec2", function() {
+      beforeEach(function() { result = vec2.divide(vecA, vecB, dest); });
+
+      it("should place values into dest", function() { expect(dest).toBeEqualish([0.333333, 0.5]); });
+      it("should return dest", function() { expect(result).toBe(dest); });
+      it("should not modify vecA", function() { expect(vecA).toBeEqualish([1, 2]); });
+      it("should not modify vecB", function() { expect(vecB).toBeEqualish([3, 4]); });
+    });
+
+    describe("without dest vec2", function() {
+      beforeEach(function() { result = vec2.divide(vecA, vecB); });
+
+      it("should place values into vecB", function() { expect(vecB).toBeEqualish([0.333333, 0.5]); });
+      it("should return vecB", function() { expect(result).toBe(vecB); });
+      it("should not modify vecA", function() { expect(vecA).toBeEqualish([1, 2]); });
+    });
+  });
+
   describe("create", function() {
     describe("with vec", function() {
       it("should clone vec's contents", function() {