/*
* Copyright (c) 2014 Gwennael Buchet
*
* License/Terms of Use
*
* Permission is hereby granted, free of charge and for the term of intellectual property rights on the Software, to any
* person obtaining a copy of this software and associated documentation files (the "Software"), to use, copy, modify
* and propagate free of charge, anywhere in the world, all or part of the Software subject to the following mandatory conditions:
*
* • The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
*
* Any failure to comply with the above shall automatically terminate the license and be construed as a breach of these
* Terms of Use causing significant harm to Gwennael Buchet.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
* WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON INFRINGEMENT. IN NO EVENT SHALL THE AUTHORS
* OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* Except as contained in this notice, the name of Gwennael Buchet shall not be used in advertising or otherwise to promote
* the use or other dealings in this Software without prior written authorization from Gwennael Buchet.
*
* These Terms of Use are subject to French law.
*/
/**
* A 2D vector object
* @module Math
* @class CGSGVector2D
* @extends {Object}
* @constructor
* @param {Number} x
* @param {Number} y
* @type {CGSGVector2D}
* @author Gwennael Buchet (gwennael.buchet@gmail.com)
*/
var CGSGVector2D = CGSGObject.extend(
{
initialize : function(x, y) {
/**
* @property x
* @type {Number}
*/
this.x = x;
/**
* @property y
* @type {Number}
*/
this.y = y;
},
/**
* @public
* @method copy
* @return {CGSGVector2D} a new CGSGVector2D, clone of this one
*/
copy : function() {
return new CGSGVector2D(this.x, this.y);
},
/**
* returns a new vector added to the value passed in parameter
* @public
* @method add
* @param {CGSGVector2D} vector
*/
add : function(vector) {
return new CGSGVector2D(this.x + vector.x, this.y + vector.y);
},
/**
* add to this vector, the value passed in parameter
* @public
* @method addEquals
* @param {CGSGVector2D} vector
*/
addEquals : function(vector) {
this.x += vector.x;
this.y += vector.y;
},
/**
* returns a new vector subtracted from the value passed in parameter
* @public
* @method subtract
* @param {CGSGVector2D} vector
*/
subtract : function(vector) {
return new CGSGVector2D(this.x - vector.x, this.y - vector.y);
},
/**
* subtract to this vector, the value passed in parameter
* @public
* @method subtractEquals
* @param {CGSGVector2D} vector
*/
subtractEquals : function(vector) {
this.x -= vector.x;
this.y -= vector.y;
},
/**
* returns a new vector multiplied to the value passed in parameter
* @public
* @method multiply
* @param {CGSGVector2D} vector
*/
multiply : function(vector) {
return new CGSGVector2D(this.x * vector.x, this.y * vector.y);
},
/**
* multiply to this vector, the value passed in parameter
* @public
* @method multiplyEquals
* @param {CGSGVector2D} vector
*/
multiplyEquals : function(vector) {
this.x *= vector.x;
this.y *= vector.y;
},
/**
* return a new vector divided by the value passed in parameter
* @public
* @method divide
* @param {CGSGVector2D} vector
*/
divide : function(vector) {
return new CGSGVector2D(this.x / vector.x, this.y / vector.y);
},
/**
* divide to this vector, the value passed in parameter
* @public
* @method divideEquals
* @param {CGSGVector2D} vector
*/
divideEquals : function(vector) {
this.x /= vector.x;
this.y /= vector.y;
},
/**
* Multiply x and y by f
* @public
* @method multiplyByFloat
* @param {Number} f
*/
multiplyByFloat : function(f) {
return new CGSGVector2D(this.x * f, this.y * f);
},
/**
* Multiply x and y by f
* @public
* @method multiplyByFloatEquals
* @param {Number} f
*/
multiplyByFloatEquals : function(f) {
this.x *= f;
this.y *= f;
},
/**
* Divide x and y by f
* @public
* @method divideByFloat
* @param {Number} f
*/
divideByFloat : function(f) {
return new CGSGVector2D(this.x / f, this.y / f);
},
/**
* Divide x and y by f
* @public
* @method divideByFloatEquals
* @param {Number} f
*/
divideByFloatEquals : function(f) {
this.x /= f;
this.y /= f;
},
/**
* Compute the euclidian distance between this vector and the one passe in parameter
* @public
* @method getDistance
* @param {CGSGVector2D} vector
* @return {Number}
*/
getDistance : function(vector) {
return Math.sqrt(
Math.pow(this.x - vector.x, 2) +
Math.pow(this.y - vector.y, 2)
);
},
/**
* rotate this vector around its origin
* @public
* @method rotate
* @param {Number} angle
*/
rotate : function(angle) {
var ca = Math.cos(angle);
var sa = Math.sin(angle);
this.x = this.x * ca + this.y * sa;
this.y = this.x * sa - this.y * ca;
},
/**
* @public
* @method getLength
* @return {Number}
*/
getLength : function() {
return Math.sqrt((this.x * this.x) + (this.y * this.y));
},
/**
* @public
* @method getSquaredLength
* @return {Number}
*/
getSquaredLength : function() {
return (this.x * this.x) + (this.y * this.y);
},
/**
* Normalize this vector
* @public
* @method normalize
*/
normalize : function() {
var scalefactor;
var length = this.getLength();
//return if length is 1 or 0
if (length == 1 || length == 0) {
return;
}
scalefactor = 1.0 / length;
this.x *= scalefactor;
this.y *= scalefactor;
},
/**
* Determines if a given vector is to the right or left of this vector.
* @public
* @method sign
*/
sign : function(vector) {
var perpVector = this.perp();
return perpVector.dot(vector) < 0 ? -1 : 1;
},
/**
* Get dot product of this vector and another vector
* @public
* @method dot
*/
dot : function(vector) {
return this.x * vector.x + this.y * vector.y;
},
/**
* Get cross product of this vector and another vector
* @public
* @method cross
*/
cross : function(vector) {
return this.x * vector.y - this.y * vector.x;
},
/**
* Get unit vector of this vector and another vector
* @public
* @method unit
*/
unit : function() {
return this.divide(this.getLength());
},
/**
* Get approximation of unit vector of this vector and another vector
* @public
* @method unitFast
*/
unitFast : function() {
var ax = Math.abs(this.x);
var ay = Math.abs(this.y);
// Create a ratio
var ratio = 1 / Math.max(ax, ay)
ratio = ratio * (1.29289 - (ax + ay) * ratio * 0.29289)
// Multiply by ratio
return this.multiplyByFloat(ratio);
},
/**
* Get unit vector of this vector and another vector
* @public
* @method unitEquals
*/
unitEquals : function() {
this.divideEquals(this.getLength());
},
/**
* Get a perpendicular vector of this vector
* @public
* @method perp
*/
perp : function() {
return new CGSGVector2D(-this.y, this.x);
},
/**
* Get a vector perpendicular to this vector and another vector
* @public
* @method perpendicular
*/
perpendicular : function(vector) {
return this.subtract(this.project(vector));
},
/**
* Get a projected vector of this vector and another vector
* @public
* @method project
*/
project : function(vector) {
var percent = this.dot(vector) / vector.dot(vector);
return vector.multiply(percent);
},
/**
* Get a string representing this vector
* @public
* @method toString
*/
toString : function() {
return this.x + "," + this.y;
}
}
);
