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// Copyright 2008 The Closure Library Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS-IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
/**
* @fileoverview A utility class for representing three-dimensional points.
*
* Based heavily on coordinate.js by:
*/
goog.provide('goog.math.Coordinate3');
/**
* Class for representing coordinates and positions in 3 dimensions.
*
* @param {number=} opt_x X coordinate, defaults to 0.
* @param {number=} opt_y Y coordinate, defaults to 0.
* @param {number=} opt_z Z coordinate, defaults to 0.
* @struct
* @constructor
*/
goog.math.Coordinate3 = function(opt_x, opt_y, opt_z) {
/**
* X-value
* @type {number}
*/
this.x = goog.isDef(opt_x) ? opt_x : 0;
/**
* Y-value
* @type {number}
*/
this.y = goog.isDef(opt_y) ? opt_y : 0;
/**
* Z-value
* @type {number}
*/
this.z = goog.isDef(opt_z) ? opt_z : 0;
};
/**
* Returns a new copy of the coordinate.
*
* @return {!goog.math.Coordinate3} A clone of this coordinate.
*/
goog.math.Coordinate3.prototype.clone = function() {
return new goog.math.Coordinate3(this.x, this.y, this.z);
};
if (goog.DEBUG) {
/**
* Returns a nice string representing the coordinate.
*
* @return {string} In the form (50, 73, 31).
* @override
*/
goog.math.Coordinate3.prototype.toString = function() {
return '(' + this.x + ', ' + this.y + ', ' + this.z + ')';
};
}
/**
* Compares coordinates for equality.
*
* @param {goog.math.Coordinate3} a A Coordinate3.
* @param {goog.math.Coordinate3} b A Coordinate3.
* @return {boolean} True iff the coordinates are equal, or if both are null.
*/
goog.math.Coordinate3.equals = function(a, b) {
if (a == b) {
return true;
}
if (!a || !b) {
return false;
}
return a.x == b.x && a.y == b.y && a.z == b.z;
};
/**
* Returns the distance between two coordinates.
*
* @param {goog.math.Coordinate3} a A Coordinate3.
* @param {goog.math.Coordinate3} b A Coordinate3.
* @return {number} The distance between {@code a} and {@code b}.
*/
goog.math.Coordinate3.distance = function(a, b) {
var dx = a.x - b.x;
var dy = a.y - b.y;
var dz = a.z - b.z;
return Math.sqrt(dx * dx + dy * dy + dz * dz);
};
/**
* Returns the squared distance between two coordinates. Squared distances can
* be used for comparisons when the actual value is not required.
*
* Performance note: eliminating the square root is an optimization often used
* in lower-level languages, but the speed difference is not nearly as
* pronounced in JavaScript (only a few percent.)
*
* @param {goog.math.Coordinate3} a A Coordinate3.
* @param {goog.math.Coordinate3} b A Coordinate3.
* @return {number} The squared distance between {@code a} and {@code b}.
*/
goog.math.Coordinate3.squaredDistance = function(a, b) {
var dx = a.x - b.x;
var dy = a.y - b.y;
var dz = a.z - b.z;
return dx * dx + dy * dy + dz * dz;
};
/**
* Returns the difference between two coordinates as a new
* goog.math.Coordinate3.
*
* @param {goog.math.Coordinate3} a A Coordinate3.
* @param {goog.math.Coordinate3} b A Coordinate3.
* @return {!goog.math.Coordinate3} A Coordinate3 representing the difference
* between {@code a} and {@code b}.
*/
goog.math.Coordinate3.difference = function(a, b) {
return new goog.math.Coordinate3(a.x - b.x, a.y - b.y, a.z - b.z);
};
/**
* Returns the contents of this coordinate as a 3 value Array.
*
* @return {!Array<number>} A new array.
*/
goog.math.Coordinate3.prototype.toArray = function() {
return [this.x, this.y, this.z];
};
/**
* Converts a three element array into a Coordinate3 object. If the value
* passed in is not an array, not array-like, or not of the right length, an
* error is thrown.
*
* @param {Array<number>} a Array of numbers to become a coordinate.
* @return {!goog.math.Coordinate3} A new coordinate from the array values.
* @throws {Error} When the oject passed in is not valid.
*/
goog.math.Coordinate3.fromArray = function(a) {
if (a.length <= 3) {
return new goog.math.Coordinate3(a[0], a[1], a[2]);
}
throw new Error('Conversion from an array requires an array of length 3');
};
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