mirror of
https://github.com/logsol/chuck.js.git
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76 lines
2.2 KiB
JavaScript
76 lines
2.2 KiB
JavaScript
/**
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* @author Adrien Brault <adrien.brault@gmail.com>
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*/
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/**
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* @class Polygon
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* @constructor
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* @param points* {Array(Point)|Array(Number)|Point...|Number...} This can be an array of Points that form the polygon,
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* a flat array of numbers that will be interpreted as [x,y, x,y, ...], or the arguments passed can be
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* all the points of the polygon e.g. `new PIXI.Polygon(new PIXI.Point(), new PIXI.Point(), ...)`, or the
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* arguments passed can be flat x,y values e.g. `new PIXI.Polygon(x,y, x,y, x,y, ...)` where `x` and `y` are
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* Numbers.
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*/
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PIXI.Polygon = function(points)
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{
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//if points isn't an array, use arguments as the array
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if(!(points instanceof Array))points = Array.prototype.slice.call(arguments);
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//if this is a flat array of numbers, convert it to points
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if(points[0] instanceof PIXI.Point)
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{
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var p = [];
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for(var i = 0, il = points.length; i < il; i++)
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{
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p.push(points[i].x, points[i].y);
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}
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points = p;
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}
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this.closed = true;
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this.points = points;
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};
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/**
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* Creates a clone of this polygon
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*
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* @method clone
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* @return {Polygon} a copy of the polygon
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*/
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PIXI.Polygon.prototype.clone = function()
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{
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var points = this.points.slice();
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return new PIXI.Polygon(points);
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};
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/**
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* Checks whether the x and y coordinates passed to this function are contained within this polygon
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*
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* @method contains
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* @param x {Number} The X coordinate of the point to test
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* @param y {Number} The Y coordinate of the point to test
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* @return {Boolean} Whether the x/y coordinates are within this polygon
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*/
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PIXI.Polygon.prototype.contains = function(x, y)
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{
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var inside = false;
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// use some raycasting to test hits
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// https://github.com/substack/point-in-polygon/blob/master/index.js
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var length = this.points.length / 2;
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for(var i = 0, j = length - 1; i < length; j = i++)
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{
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var xi = this.points[i * 2], yi = this.points[i * 2 + 1],
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xj = this.points[j * 2], yj = this.points[j * 2 + 1],
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intersect = ((yi > y) !== (yj > y)) && (x < (xj - xi) * (y - yi) / (yj - yi) + xi);
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if(intersect) inside = !inside;
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}
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return inside;
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};
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// constructor
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PIXI.Polygon.prototype.constructor = PIXI.Polygon;
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