@smoud/tiny/src/math/shapes/Circle.js

Fast and tiny JavaScript library for HTML5 game and playable ads creation.

import { Rectangle } from './Rectangle';
import { SHAPES } from '../../constants';

/**
 * @author Chad Engler <chad@pantherdev.com>
 */

/**
 * The Circle object can be used to specify a hit area for displayObjects
 *
 * @class Circle
 * @constructor
 * @param x {Number} The X coordinate of the center of this circle
 * @param y {Number} The Y coordinate of the center of this circle
 * @param radius {Number} The radius of the circle
 */
var Circle = function (x, y, radius) {
    /**
     * @property x
     * @type Number
     * @default 0
     */
    this.x = x || 0;

    /**
     * @property y
     * @type Number
     * @default 0
     */
    this.y = y || 0;

    /**
     * @property radius
     * @type Number
     * @default 0
     */
    this.radius = radius || 0;

    /**
     * The type of the object, should be one of the Graphics type consts, PIXI.Graphics.CIRC in this case
     * @property type
     * @type Number
     * @default 0
     */

    this.type = SHAPES.CIRC;
};

Circle.prototype = {
    /**
     * Creates a clone of this Circle instance
     *
     * @method clone
     * @return {Circle} a copy of the Circle
     */
    // Circle.prototype.clone = function()
    // {
    //     return new Circle(this.x, this.y, this.radius);
    // };

    /**
     * Checks whether the x and y coordinates given are contained within this circle
     *
     * @method contains
     * @param x {Number} The X coordinate of the point to test
     * @param y {Number} The Y coordinate of the point to test
     * @return {Boolean} Whether the x/y coordinates are within this Circle
     */
    contains: function (x, y) {
        if (this.radius <= 0) return false;

        var dx = this.x - x,
            dy = this.y - y,
            r2 = this.radius * this.radius;

        dx *= dx;
        dy *= dy;

        return dx + dy <= r2;
    },

    /**
     * Returns the framing rectangle of the circle as a PIXI.Rectangle object
     *
     * @method getBounds
     * @return {Rectangle} the framing rectangle
     */
    getBounds: function () {
        return new PIXI.Rectangle(
            this.x - this.radius,
            this.y - this.radius,
            this.radius * 2,
            this.radius * 2
        );
    }
};

// constructor
Circle.prototype.constructor = Circle;

export { Circle };