/**
* @author Richard Davey <rich@photonstorm.com>
* @author Adrien Brault <adrien.brault@gmail.com>
* @copyright 2014 Photon Storm Ltd.
* @license {@link https://github.com/photonstorm/phaser/blob/master/license.txt|MIT License}
*/
/**
* Creates a new Polygon.
*
* The points can be set from a variety of formats:
*
* - An array of Point objects: `[new Phaser.Point(x1, y1), ...]`
* - An array of objects with public x/y properties: `[obj1, obj2, ...]`
* - An array of paired numbers that represent point coordinates: `[x1,y1, x2,y2, ...]`
* - As separate Point arguments: `setTo(new Phaser.Point(x1, y1), ...)`
* - As separate objects with public x/y properties arguments: `setTo(obj1, obj2, ...)`
* - As separate arguments representing point coordinates: `setTo(x1,y1, x2,y2, ...)`
*
* @class Phaser.Polygon
* @constructor
* @param {Phaser.Point[]|number[]|...Phaser.Point|...number} points - The points to set.
*/
Phaser.Polygon = function () {
/**
* @property {number} type - The base object type.
*/
this.type = Phaser.POLYGON;
/**
* @property {number} area - The area of this Polygon.
*/
this.area = 0;
/**
* @property {array} _points - An array of Points that make up this Polygon.
* @private
*/
this._points = [];
if (arguments.length > 0)
{
this.setTo.apply(this, arguments);
}
/**
* @property {boolean} closed - Is the Polygon closed or not?
*/
this.closed = true;
};
Phaser.Polygon.prototype = {
/**
* Creates a copy of the given Polygon.
* This is a deep clone, the resulting copy contains new Phaser.Point objects
*
* @method Phaser.Polygon#clone
* @param {Phaser.Polygon} [output=(new Polygon)] - The polygon to update. If not specified a new polygon will be created.
* @return {Phaser.Polygon} The cloned (`output`) polygon object.
*/
clone: function (output) {
var points = this._points.slice();
if (typeof output === "undefined" || output === null)
{
output = new Phaser.Polygon(points);
}
else
{
output.setTo(points);
}
return output;
},
/**
* Checks whether the x and y coordinates are contained within this polygon.
*
* @method Phaser.Polygon#contains
* @param {number} x - The X value of the coordinate to test.
* @param {number} y - The Y value of the coordinate to test.
* @return {boolean} True if the coordinates are within this polygon, otherwise false.
*/
contains: function (x, y) {
// Adapted from http://www.ecse.rpi.edu/Homepages/wrf/Research/Short_Notes/pnpoly.html by Jonas Raoni Soares Silva
var length = this._points.length;
var inside = false;
for (var i = -1, j = length - 1; ++i < length; j = i)
{
var ix = this._points[i].x;
var iy = this._points[i].y;
var jx = this._points[j].x;
var jy = this._points[j].y;
if (((iy <= y && y < jy) || (jy <= y && y < iy)) && (x < (jx - ix) * (y - iy) / (jy - iy) + ix))
{
inside = !inside;
}
}
return inside;
},
/**
* Sets this Polygon to the given points.
*
* The points can be set from a variety of formats:
*
* - An array of Point objects: `[new Phaser.Point(x1, y1), ...]`
* - An array of objects with public x/y properties: `[obj1, obj2, ...]`
* - An array of paired numbers that represent point coordinates: `[x1,y1, x2,y2, ...]`
* - As separate Point arguments: `setTo(new Phaser.Point(x1, y1), ...)`
* - As separate objects with public x/y properties arguments: `setTo(obj1, obj2, ...)`
* - As separate arguments representing point coordinates: `setTo(x1,y1, x2,y2, ...)`
*
* `setTo` may also be called without any arguments to remove all points.
*
* @method Phaser.Polygon#setTo
* @param {Phaser.Point[]|number[]|...Phaser.Point|...number} points - The points to set.
* @return {Phaser.Polygon} This Polygon object
*/
setTo: function (points) {
this.area = 0;
this._points = [];
if (arguments.length > 0)
{
// If points isn't an array, use arguments as the array
if (!Array.isArray(points))
{
points = Array.prototype.slice.call(arguments);
}
var y0 = Number.MAX_VALUE;
// Allows for mixed-type arguments
for (var i = 0, len = points.length; i < len; i++)
{
if (typeof points[i] === 'number')
{
var p = new Phaser.Point(points[i], points[i + 1]);
i++;
}
else
{
var p = new Phaser.Point(points[i].x, points[i].y);
}
this._points.push(p);
// Lowest boundary
if (p.y < y0)
{
y0 = p.y;
}
}
this.calculateArea(y0);
}
return this;
},
/**
* Calcuates the area of the Polygon. This is available in the property Polygon.area
*
* @method Phaser.Polygon#calculateArea
* @private
* @param {number} y0 - The lowest boundary
* @return {number} The area of the Polygon.
*/
calculateArea: function (y0) {
var p1;
var p2;
var avgHeight;
var width;
for (var i = 0, len = this._points.length; i < len; i++)
{
p1 = this._points[i];
if (i === len - 1)
{
p2 = this._points[0];
}
else
{
p2 = this._points[i + 1];
}
avgHeight = ((p1.y - y0) + (p2.y - y0)) / 2;
width = p1.x - p2.x;
this.area += avgHeight * width;
}
return this.area;
}
};
Phaser.Polygon.prototype.constructor = Phaser.Polygon;
/**
* Sets and modifies the points of this polygon.
*
* See {@link Phaser.Polygon#setTo setTo} for the different kinds of arrays formats that can be assigned.
*
* @name Phaser.Polygon#points
* @property {Phaser.Point[]} points - The array of vertex points.
* @deprecated Use `setTo`.
*/
Object.defineProperty(Phaser.Polygon.prototype, 'points', {
get: function() {
return this._points;
},
set: function(points) {
if (points != null)
{
this.setTo(points);
}
else
{
// Clear the points
this.setTo();
}
}
});