// Encapsulates a 2D rectangle defined by its corner point in the top-left // and its extends in x (width) and y (height) var Rectangle = function (x, y, width, height) { if (x === undefined) { x = 0; } if (y === undefined) { y = 0; } if (width === undefined) { width = 0; } if (height === undefined) { height = 0; } this.x = x; this.y = y; this.width = width; this.height = height; }; Rectangle.prototype.constructor = Rectangle; Rectangle.prototype = { set: function (x, y, width, height) { this.x = x; this.y = y; this.width = width; this.height = height; return this; }, setPosition: function (x, y) { if (y === undefined) { y = x; } this.x = x; this.y = y; return this; }, setSize: function (width, height) { if (height === undefined) { height = width; } this.width = width; this.height = height; return this; } }; Object.defineProperties(Rectangle.prototype, { left: { enumerable: true, get: function () { return this.x; }, set: function (value) { if (value >= this.right) { this.width = 0; } else { this.width = this.right - value; } this.x = value; } }, right: { enumerable: true, get: function () { return this.x + this.width; }, set: function (value) { if (value <= this.x) { this.width = 0; } else { this.width = value - this.x; } } }, top: { enumerable: true, get: function () { return this.y; }, set: function (value) { if (value >= this.bottom) { this.height = 0; this.y = value; } else { this.height = (this.bottom - value); } } }, bottom: { enumerable: true, get: function () { return this.y + this.height; }, set: function (value) { if (value <= this.y) { this.height = 0; } else { this.height = value - this.y; } } } }); module.exports = Rectangle;