added examples in Matrix4

Source/Core/BoxTessellator.js

@@ -3,12 +3,14 @@ define([
         './DeveloperError',
         './Cartesian3',
         './ComponentDatatype',
-        './PrimitiveType'
+        './PrimitiveType',
+        './defaultValue'
     ], function(
         DeveloperError,
         Cartesian3,
         ComponentDatatype,
-        PrimitiveType) {
+        PrimitiveType,
+        defaultValue) {
     "use strict";
 
     /**
@@ -27,7 +29,7 @@ define([
          * @exception {DeveloperError} All dimensions' components must be greater than or equal to zero.
          */
         compute : function(template) {
-            template = template || {};
+            template = defaultValue(template, {});
             var minimumCorner;
             var maximumCorner;
 

Source/Core/CatmullRomSpline.js

@@ -4,14 +4,16 @@ define([
         './Matrix4',
         './Cartesian3',
         './Cartesian4',
-        './HermiteSpline'
+        './HermiteSpline',
+        './defaultValue'
     ],
     function(
         DeveloperError,
         Matrix4,
         Cartesian3,
         Cartesian4,
-        HermiteSpline) {
+        HermiteSpline,
+        defaultValue) {
     "use strict";
 
     /**
@@ -45,7 +47,7 @@ define([
      * var spline = new CatmullRomSpline(controlPoints);
      */
     var CatmullRomSpline = function(controlPoints, firstTangent, lastTangent) {
-        if (!controlPoints || !(controlPoints instanceof Array) || controlPoints.length < 3) {
+        if (typeof controlPoints === 'undefined' || !(controlPoints instanceof Array) || controlPoints.length < 3) {
             throw new DeveloperError('controlPoints is required and must be an array of objects with point and time properties, with a length of at least 3.');
         }
 
@@ -127,7 +129,7 @@ define([
     CatmullRomSpline.prototype._findIndex = function(time) {
         // Take advantage of temporal coherence by checking current, next and previous intervals
         // for containment of time.
-        var i = this._lastTimeIndex || 0;
+        var i = defaultValue(this._lastTimeIndex, 0);
         if (time >= this._points[i].time) {
             if (i + 1 < this._points.length && time < this._points[i + 1].time) {
                 return i;

Source/Core/LinearApproximation.js

@@ -77,6 +77,10 @@ define([
         var x0 = xTable[0];
         var x1 = xTable[1];
 
+        if(x0 === x1){
+            throw new DeveloperError('Divide by zero error: xTable[0] and xTable[1] are equal');
+        }
+
         for (i = 0; i < yStride; i++) {
             y0 = yTable[i];
             y1 = yTable[i + yStride];

Source/Core/Matrix4.js

@@ -797,6 +797,17 @@ define([
      * @return {Array} The modified Array parameter or a new Array instance if one was not provided.
      *
      * @exception {DeveloperError} matrix is required.
+	 *
+	 * @example
+	 * //converts a matrix of order 4 to an array
+	 * // m = [10.0, 11.0, 12.0, 13.0]
+	 * //     [14.0, 15.0, 16.0, 17.0]
+	 * //     [18.0, 19.0, 20.0, 21.0]
+	 * //     [22.0, 23.0, 24.0, 25.0]
+	 * var a = Matrix4.toArray(m);
+	 * 
+	 * //creates a = [10.0, 11.0, 12.0, 13.0, 14.0, 15.0, 16.0, 17.0, 18.0, 19.0, 20.0, 21.0, 22.0, 23.0, 24.0, 25.0]
+	 *
      */
     Matrix4.toArray = function(matrix, result) {
         if (typeof matrix === 'undefined') {
@@ -867,6 +878,23 @@ define([
      * @exception {DeveloperError} index is required and must be 0, 1, 2, or 3.
      *
      * @see Cartesian4
+	 *
+	 * @example
+	 * //returns a Cartesian4 instance with values from the specified column
+	 * // m = [10.0, 11.0, 12.0, 13.0]
+	 * //     [14.0, 15.0, 16.0, 17.0]
+	 * //     [18.0, 19.0, 20.0, 21.0]
+	 * //     [22.0, 23.0, 24.0, 25.0]
+	 * 
+	 * //Example 1: Creates a Cartesian instance 
+	 * var a = Matrix4.getColumn(m, 2);
+	 * 
+	 * //Example 1: Creates a Cartesian instance 
+	 * var a = new Cartesian4();
+	 * Matrix4.getColumn(m, 2, a);
+	 *
+	 * //creates a.x = 12.0; a.y = 16.0; a.z = 20.0; a.w = 24.0;
+	 *
      */
     Matrix4.getColumn = function(matrix, index, result) {
         if (typeof matrix === 'undefined') {
@@ -908,6 +936,22 @@ define([
      * @exception {DeveloperError} index is required and must be 0, 1, 2, or 3.
      *
      * @see Cartesian4
+	 *
+	 * @example
+	 * //create a new matrix of order 4 with new column values from the Cartesian4 instance
+	 * // m = [10.0, 11.0, 12.0, 13.0]
+	 * //     [14.0, 15.0, 16.0, 17.0]
+	 * //     [18.0, 19.0, 20.0, 21.0]
+	 * //     [22.0, 23.0, 24.0, 25.0]
+	 * 
+	 * var a = Matrix4.setColumn(m, 2, new Cartesian4(99.0, 98.0, 97.0, 96.0));
+	 *
+	 * // m still remains the same
+	 * // a = [10.0, 11.0, 99.0, 13.0]
+	 * //     [14.0, 15.0, 98.0, 17.0]
+	 * //     [18.0, 19.0, 97.0, 21.0]
+	 * //     [22.0, 23.0, 96.0, 25.0]
+	 *
      */
     Matrix4.setColumn = function(matrix, index, cartesian, result) {
         if (typeof matrix === 'undefined') {
@@ -941,6 +985,22 @@ define([
      * @exception {DeveloperError} index is required and must be 0, 1, 2, or 3.
      *
      * @see Cartesian4
+	 *
+	 * @example
+	 * //returns a Cartesian4 instance with values from the specified column
+	 * // m = [10.0, 11.0, 12.0, 13.0]
+	 * //     [14.0, 15.0, 16.0, 17.0]
+	 * //     [18.0, 19.0, 20.0, 21.0]
+	 * //     [22.0, 23.0, 24.0, 25.0]
+	 * 
+	 * //Example 1: Creates a Cartesian instance 
+	 * var a = Matrix4.getColumn(m, 2);
+	 * 
+	 * //Example 1: Creates a Cartesian instance 
+	 * var a = new Cartesian4();
+	 * Matrix4.getColumn(m, 2, a);
+	 *
+	 * //creates a.x = 18.0; a.y = 19.0; a.z = 20.0; a.w = 21.0;
      */
     Matrix4.getRow = function(matrix, index, result) {
         if (typeof matrix === 'undefined') {
@@ -981,6 +1041,22 @@ define([
      * @exception {DeveloperError} index is required and must be 0, 1, 2, or 3.
      *
      * @see Cartesian4
+	 *
+	 * @example
+	 * //create a new matrix of order 4 with new row values from the Cartesian4 instance
+	 * // m = [10.0, 11.0, 12.0, 13.0]
+	 * //     [14.0, 15.0, 16.0, 17.0]
+	 * //     [18.0, 19.0, 20.0, 21.0]
+	 * //     [22.0, 23.0, 24.0, 25.0]
+	 * 
+	 * var a = Matrix4.setRow(m, 2, new Cartesian4(99.0, 98.0, 97.0, 96.0));
+	 *
+	 * // m still remains the same
+	 * // a = [10.0, 11.0, 12.0, 13.0]
+	 * //     [14.0, 15.0, 16.0, 17.0]
+	 * //     [99.0, 98.0, 97.0, 96.0]
+	 * //     [22.0, 23.0, 24.0, 25.0]
+	 *
      */
     Matrix4.setRow = function(matrix, index, cartesian, result) {
         if (typeof matrix === 'undefined') {
@@ -1354,6 +1430,22 @@ define([
      * @return {Matrix4} The modified result parameter or a new Matrix4 instance if one was not provided.
      *
      * @exception {DeveloperError} matrix is required.
+	 *
+	 * @example
+	 * //create a new matrix of order 4 
+	 * // m = [10.0, 11.0, 12.0, 13.0]
+	 * //     [14.0, 15.0, 16.0, 17.0]
+	 * //     [18.0, 19.0, 20.0, 21.0]
+	 * //     [22.0, 23.0, 24.0, 25.0]
+	 * 
+	 * var a = Matrix4.negate(m);
+	 *
+	 * // m still remains the same
+	 * // a = [-10.0, -11.0, -12.0, -13.0]
+	 * //     [-14.0, -15.0, -16.0, -17.0]
+	 * //     [-18.0, -19.0, -20.0, -21.0]
+	 * //     [-22.0, -23.0, -24.0, -25.0]
+	 *
      */
     Matrix4.negate = function(matrix, result) {
         if (typeof matrix === 'undefined') {
@@ -1394,6 +1486,22 @@ define([
      * @return {Matrix4} The modified result parameter or a new Matrix4 instance if one was not provided.
      *
      * @exception {DeveloperError} matrix is required.
+	 *
+	 * @example
+	 * //create a new matrix of order 4 which is a transpose of the given matrix
+	 * // m = [10.0, 11.0, 12.0, 13.0]
+	 * //     [14.0, 15.0, 16.0, 17.0]
+	 * //     [18.0, 19.0, 20.0, 21.0]
+	 * //     [22.0, 23.0, 24.0, 25.0]
+	 * 
+	 * var a = Matrix4.negate(m);
+	 *
+	 * // m still remains the same
+	 * // a = [10.0, 14.0, 18.0, 22.0]
+	 * //     [11.0, 15.0, 19.0, 23.0]
+	 * //     [12.0, 16.0, 20.0, 24.0]
+	 * //     [13.0, 17.0, 21.0, 25.0]
+	 *
      */
     Matrix4.transpose = function(matrix, result) {
         if (typeof matrix === 'undefined') {

Source/Core/PlaneTessellator.js

@@ -2,11 +2,13 @@
 define([
         './DeveloperError',
         './Cartesian2',
-        './PrimitiveType'
+        './PrimitiveType',
+        './defaultValue'
     ], function(
         DeveloperError,
         Cartesian2,
-        PrimitiveType) {
+        PrimitiveType,
+        defaultValue) {
     "use strict";
 
     /**
@@ -24,8 +26,8 @@ define([
          * @exception {DeveloperError} Resolution must be greater than one in both the x and y directions.
          */
         compute : function(template) {
-            template = template || {};
-            var resolution = template.resolution || new Cartesian2(2, 2);
+            template = defaultValue(template, {});
+            var resolution = defaultValue(template.resolution, new Cartesian2(2, 2));
             var onInterpolation = template.onInterpolation; // Can be undefined
 
             if (resolution.x <= 1 || resolution.y <= 1) {

Source/Core/ScreenSpaceEventHandler.js

@@ -5,14 +5,16 @@ define([
         './Cartesian2',
         './JulianDate',
         './ScreenSpaceEventType',
-        './KeyboardEventModifier'
+        './KeyboardEventModifier',
+        './defaultValue'
     ], function(
         DeveloperError,
         destroyObject,
         Cartesian2,
         JulianDate,
         ScreenSpaceEventType,
-        KeyboardEventModifier) {
+        KeyboardEventModifier,
+        defaultValue) {
     "use strict";
 
     /**
@@ -61,7 +63,7 @@ define([
         // or determined based on the platform?
         this._clickPixelTolerance = 5;
 
-        this._element = element || document;
+        this._element = defaultValue(element, document);
 
         this._register();
     };

Source/Core/Shapes.js

@@ -5,14 +5,16 @@ define([
         './Cartesian2',
         './Cartesian3',
         './Quaternion',
-        './Matrix3'
+        './Matrix3',
+        './defaultValue'
     ], function(
         DeveloperError,
         CesiumMath,
         Cartesian2,
         Cartesian3,
         Quaternion,
-        Matrix3) {
+        Matrix3,
+        defaultValue) {
     "use strict";
 
     function _computeEllipseQuadrant(cb, cbRadius, aSqr, bSqr, ab, ecc, mag, unitPos, eastVec, northVec, bearing,
@@ -102,7 +104,7 @@ define([
          *     Cartographic.fromDegrees(-75.59777, 40.03883, 0.0)), 100000.0));
          */
         computeCircleBoundary : function(ellipsoid, center, radius, granularity) {
-            if (!ellipsoid || !center || !radius) {
+            if (typeof ellipsoid === 'undefined' || typeof center === 'undefined' || typeof radius === 'undefined') {
                 throw new DeveloperError('ellipsoid, center, and radius are required.');
             }
 
@@ -153,7 +155,7 @@ define([
          *      Cartographic.fromDegrees(-75.59777, 40.03883)), 500000.0, 300000.0, Math.toRadians(60)));
          */
         computeEllipseBoundary : function(ellipsoid, center, semiMajorAxis, semiMinorAxis, bearing, granularity) {
-            if (!ellipsoid || !center || !semiMajorAxis || !semiMinorAxis) {
+            if (typeof ellipsoid === 'undefined' || typeof center === 'undefined' || typeof semiMajorAxis === 'undefined' || typeof semiMinorAxis === 'undefined') {
                 throw new DeveloperError('ellipsoid, center, semiMajorAxis, and semiMinorAxis are required.');
             }
 

Source/Core/Spherical.js

@@ -1,5 +1,5 @@
 /*global define*/
-define(function() {
+define(['./defaultValue'], function(defaultValue) {
     "use strict";
 
     /**
@@ -13,9 +13,9 @@ define(function() {
      * @param {Number} [magnitude=1.0] The linear coordinate measured from the origin.
      */
     var Spherical = function(clock, cone, magnitude) {
-        this.clock = typeof clock === 'undefined' ? 0.0 : clock;
-        this.cone = typeof cone === 'undefined' ? 0.0 : cone;
-        this.magnitude = typeof magnitude === 'undefined' ? 1.0 : magnitude;
+        this.clock = defaultValue(clock, 0.0);
+        this.cone = defaultValue(cone, 0.0);
+        this.magnitude = defaultValue(magnitude, 1.0);
     };
 
     /**
@@ -28,9 +28,7 @@ define(function() {
      * @returns The modified result parameter, or a new instance if one was not provided.
      */
     Spherical.fromCartesian3 = function(cartesian3, result) {
-        if (typeof result === 'undefined') {
-            result = new Spherical();
-        }
+        result = defaultValue(result, new Spherical());
         var x = cartesian3.x;
         var y = cartesian3.y;
         var z = cartesian3.z;
@@ -51,9 +49,7 @@ define(function() {
      * @return The modified result parameter or a new instance if result was undefined.
      */
     Spherical.clone = function(spherical, result) {
-        if (typeof result === 'undefined') {
-            result = new Spherical();
-        }
+        result = defaultValue(result, new Spherical());
         result.clock = spherical.clock;
         result.cone = spherical.cone;
         result.magnitude = spherical.magnitude;
@@ -70,9 +66,7 @@ define(function() {
      * @return The modified result parameter or a new instance if result was undefined.
      */
     Spherical.normalize = function(spherical, result) {
-        if (typeof result === 'undefined') {
-            result = new Spherical();
-        }
+        result = defaultValue(result, new Spherical());
         result.clock = spherical.clock;
         result.cone = spherical.cone;
         result.magnitude = 1.0;
@@ -108,7 +102,7 @@ define(function() {
      * @return true if the first spherical is within the provided epsilon of the second spherical, false otherwise.
      */
     Spherical.equalsEpsilon = function(left, right, epsilon) {
-        epsilon = typeof epsilon === 'undefined' ? 0.0 : epsilon;
+        epsilon = defaultValue(epsilon, 0.0);
         return (left === right) ||
                ((typeof left !== 'undefined') &&
                 (typeof right !== 'undefined') &&