* Creates a new Circle object with the center coordinate specified by the x and y parameters and the diameter specified by the diameter parameter. If you call this function without parameters, a circle with x, y, diameter and radius properties set to 0 is created.
* @class Circle
* @classdesc Phaser - Circle
* @constructor
* @param {number} [x] The x coordinate of the center of the circle.
* @param {number} [y] The y coordinate of the center of the circle.
* @param {number} [diameter] The diameter of the circle.
* @return {Phaser.Circle} This circle object
**/
Phaser.Circle = function (x, y, diameter) {
x = x || 0;
y = y || 0;
diameter = diameter || 0;
/**
* @property {number} x - The x coordinate of the center of the circle.
**/
this.x = x;
/**
* @property {number} y - The y coordinate of the center of the circle.
**/
this.y = y;
/**
* @property {number} _diameter - The diameter of the circle.
* @private
**/
this._diameter = diameter;
if (diameter > 0)
{
/**
* @property {number} _radius - The radius of the circle.
* @private
**/
this._radius = diameter * 0.5;
}
else
{
this._radius = 0;
}
};
Phaser.Circle.prototype = {
/**
* The circumference of the circle.
* @method Phaser.Circle#circumference
* @return {number}
**/
circumference: function () {
return 2 * (Math.PI * this._radius);
},
/**
* Sets the members of Circle to the specified values.
* @method Phaser.Circle#setTo
* @param {number} x - The x coordinate of the center of the circle.
* @param {number} y - The y coordinate of the center of the circle.
* @param {number} diameter - The diameter of the circle in pixels.
* @return {Circle} This circle object.
**/
setTo: function (x, y, diameter) {
this.x = x;
this.y = y;
this._diameter = diameter;
this._radius = diameter * 0.5;
return this;
},
/**
* Copies the x, y and diameter properties from any given object to this Circle.
* Returns a new Circle object with the same values for the x, y, width, and height properties as this Circle object.
* @method Phaser.Circle#clone
* @param {Phaser.Circle} out - Optional Circle object. If given the values will be set into the object, otherwise a brand new Circle object will be created and returned.
* @return {Phaser.Circle} The cloned Circle object.
*/
clone: function(out) {
if (typeof out === "undefined") { out = new Phaser.Circle(); }
return out.setTo(a.x, a.y, a.diameter);
},
/**
* Return true if the given x/y coordinates are within this Circle object.
* @method Phaser.Circle#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 circle, otherwise false.
*/
contains: function (x, y) {
return Phaser.Circle.contains(this, x, y);
},
/**
* Returns a Point object containing the coordinates of a point on the circumference of the Circle based on the given angle.
* @method Phaser.Circle#circumferencePoint
* @param {number} angle - The angle in radians (unless asDegrees is true) to return the point from.
* @param {boolean} asDegrees - Is the given angle in radians (false) or degrees (true)?
* @param {Phaser.Point} [out] - An optional Point object to put the result in to. If none specified a new Point object will be created.
* @return {Phaser.Point} The Point object holding the result.
*/
circumferencePoint: function (angle, asDegrees, out) {
* Adjusts the location of the Circle object, as determined by its center coordinate, by the specified amounts.
* @method Phaser.Circle#offset
* @param {number} dx - Moves the x value of the Circle object by this amount.
* @param {number} dy - Moves the y value of the Circle object by this amount.
* @return {Circle} This Circle object.
**/
offset: function (dx, dy) {
this.x += dx;
this.y += dy;
return this;
},
/**
* Adjusts the location of the Circle object using a Point object as a parameter. This method is similar to the Circle.offset() method, except that it takes a Point object as a parameter.
* @method Phaser.Circle#offsetPoint
* @param {Point} point A Point object to use to offset this Circle object (or any valid object with exposed x and y properties).
* @return {Circle} This Circle object.
**/
offsetPoint: function (point) {
return this.offset(point.x, point.y);
},
/**
* Returns a string representation of this object.
* @method Phaser.Circle#toString
* @return {string} a string representation of the instance.
* The x coordinate of the leftmost point of the circle. Changing the left property of a Circle object has no effect on the x and y properties. However it does affect the diameter, whereas changing the x value does not affect the diameter property.
* @name Phaser.Circle#left
* @propety {number} left - Gets or sets the value of the leftmost point of the circle.
* The x coordinate of the rightmost point of the circle. Changing the right property of a Circle object has no effect on the x and y properties. However it does affect the diameter, whereas changing the x value does not affect the diameter property.
* @name Phaser.Circle#right
* @property {number} right - Gets or sets the value of the rightmost point of the circle.
* The sum of the y minus the radius property. Changing the top property of a Circle object has no effect on the x and y properties, but does change the diameter.
* @name Phaser.Circle#top
* @property {number} top - Gets or sets the top of the circle.
* The sum of the y and radius properties. Changing the bottom property of a Circle object has no effect on the x and y properties, but does change the diameter.
* @name Phaser.Circle#bottom
* @property {number} bottom - Gets or sets the bottom of the circle.
* Determines whether or not this Circle object is empty. Will return a value of true if the Circle objects diameter is less than or equal to 0; otherwise false.
* If set to true it will reset all of the Circle objects properties to 0. A Circle object is empty if its diameter is less than or equal to 0.
* @name Phaser.Circle#empty
* @property {boolean} empty - Gets or sets the empty state of the circle.
* Return true if the given x/y coordinates are within the Circle object.
* @method Phaser.Circle.contains
* @param {Phaser.Circle} a - The Circle to be checked.
* @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 circle, otherwise false.
*/
Phaser.Circle.contains = function (a, x, y) {
// Check if x/y are within the bounds first
if (x >= a.left && x <= a.right && y >= a.top && y <= a.bottom) {
var dx = (a.x - x) * (a.x - x);
var dy = (a.y - y) * (a.y - y);
return (dx + dy) <= (a.radius * a.radius);
}
return false;
};
/**
* Determines whether the two Circle objects match. This method compares the x, y and diameter properties.
* @method Phaser.Circle.equals
* @param {Phaser.Circle} a - The first Circle object.
* @param {Phaser.Circle} b - The second Circle object.
* @return {boolean} A value of true if the object has exactly the same values for the x, y and diameter properties as this Circle object; otherwise false.
