Phaser Source: src/physics/arcade/Body.js

# Source: src/physics/arcade/Body.js

    /**
    * @author       Richard Davey <rich@photonstorm.com>
    * @copyright    2016 Photon Storm Ltd.
    * @license      {@link https://github.com/photonstorm/phaser/blob/master/license.txt|MIT License}
    */

    /**
    * The Physics Body is linked to a single Sprite. All physics operations should be performed against the body rather than
    * the Sprite itself. For example you can set the velocity, acceleration, bounce values etc all on the Body.
    *
    * @class Phaser.Physics.Arcade.Body
    * @constructor
    * @param {Phaser.Sprite} sprite - The Sprite object this physics body belongs to.
    */
    Phaser.Physics.Arcade.Body = function (sprite) {

        /**
        * @property {Phaser.Sprite} sprite - Reference to the parent Sprite.
        */
        this.sprite = sprite;

        /**
        * @property {Phaser.Game} game - Local reference to game.
        */
        this.game = sprite.game;

        /**
        * @property {number} type - The type of physics system this body belongs to.
        */
        this.type = Phaser.Physics.ARCADE;

        /**
        * @property {boolean} enable - A disabled body won't be checked for any form of collision or overlap or have its pre/post updates run.
        * @default
        */
        this.enable = true;

        /**
        * If `true` this Body is using circular collision detection. If `false` it is using rectangular.
        * Use `Body.setCircle` to control the collision shape this Body uses.
        * @property {boolean} isCircle
        * @default
        * @readOnly
        */
        this.isCircle = false;

        /**
        * The radius of the circular collision shape this Body is using if Body.setCircle has been enabled.
        * If you wish to change the radius then call `setCircle` again with the new value.
        * If you wish to stop the Body using a circle then call `setCircle` with a radius of zero (or undefined).
        * @property {number} radius
        * @default
        * @readOnly
        */
        this.radius = 0;

        /**
        * @property {Phaser.Point} offset - The offset of the Physics Body from the Sprite x/y position.
        */
        this.offset = new Phaser.Point();

        /**
        * @property {Phaser.Point} position - The position of the physics body.
        * @readonly
        */
        this.position = new Phaser.Point(sprite.x, sprite.y);

        /**
        * @property {Phaser.Point} prev - The previous position of the physics body.
        * @readonly
        */
        this.prev = new Phaser.Point(this.position.x, this.position.y);

        /**
        * @property {boolean} allowRotation - Allow this Body to be rotated? (via angularVelocity, etc)
        * @default
        */
        this.allowRotation = true;

        /**
        * The Body's rotation in degrees, as calculated by its angularVelocity and angularAcceleration. Please understand that the collision Body
        * itself never rotates, it is always axis-aligned. However these values are passed up to the parent Sprite and updates its rotation.
        * @property {number} rotation
        */
        this.rotation = sprite.angle;

        /**
        * @property {number} preRotation - The previous rotation of the physics body.
        * @readonly
        */
        this.preRotation = sprite.angle;

        /**
        * @property {number} width - The calculated width of the physics body.
        * @readonly
        */
        this.width = sprite.width;

        /**
        * @property {number} height - The calculated height of the physics body.
        * @readonly
        */
        this.height = sprite.height;

        /**
        * @property {number} sourceWidth - The un-scaled original size.
        * @readonly
        */
        this.sourceWidth = sprite.width;

        /**
        * @property {number} sourceHeight - The un-scaled original size.
        * @readonly
        */
        this.sourceHeight = sprite.height;

        if (sprite.texture)
        {
            this.sourceWidth = sprite.texture.frame.width;
            this.sourceHeight = sprite.texture.frame.height;
        }

        /**
        * @property {number} halfWidth - The calculated width / 2 of the physics body.
        * @readonly
        */
        this.halfWidth = Math.abs(sprite.width / 2);

        /**
        * @property {number} halfHeight - The calculated height / 2 of the physics body.
        * @readonly
        */
        this.halfHeight = Math.abs(sprite.height / 2);

        /**
        * @property {Phaser.Point} center - The center coordinate of the Physics Body.
        * @readonly
        */
        this.center = new Phaser.Point(sprite.x + this.halfWidth, sprite.y + this.halfHeight);

        /**
        * @property {Phaser.Point} velocity - The velocity, or rate of change in speed of the Body. Measured in pixels per second.
        */
        this.velocity = new Phaser.Point();

        /**
        * @property {Phaser.Point} newVelocity - The new velocity. Calculated during the Body.preUpdate and applied to its position.
        * @readonly
        */
        this.newVelocity = new Phaser.Point();

        /**
        * @property {Phaser.Point} deltaMax - The Sprite position is updated based on the delta x/y values. You can set a cap on those (both +-) using deltaMax.
        */
        this.deltaMax = new Phaser.Point();

        /**
        * @property {Phaser.Point} acceleration - The acceleration is the rate of change of the velocity. Measured in pixels per second squared.
        */
        this.acceleration = new Phaser.Point();

        /**
        * @property {Phaser.Point} drag - The drag applied to the motion of the Body.
        */
        this.drag = new Phaser.Point();

        /**
        * @property {boolean} allowGravity - Allow this Body to be influenced by gravity? Either world or local.
        * @default
        */
        this.allowGravity = true;

        /**
        * @property {Phaser.Point} gravity - A local gravity applied to this Body. If non-zero this over rides any world gravity, unless Body.allowGravity is set to false.
        */
        this.gravity = new Phaser.Point();

        /**
        * @property {Phaser.Point} bounce - The elasticity of the Body when colliding. bounce.x/y = 1 means full rebound, bounce.x/y = 0.5 means 50% rebound velocity.
        */
        this.bounce = new Phaser.Point();

        /**
        * The elasticity of the Body when colliding with the World bounds.
        * By default this property is `null`, in which case `Body.bounce` is used instead. Set this property
        * to a Phaser.Point object in order to enable a World bounds specific bounce value.
        * @property {Phaser.Point} worldBounce
        */
        this.worldBounce = null;

        /**
        * A Signal that is dispatched when this Body collides with the world bounds.
        * Due to the potentially high volume of signals this could create it is disabled by default.
        * To use this feature set this property to a Phaser.Signal: `sprite.body.onWorldBounds = new Phaser.Signal()`
        * and it will be called when a collision happens, passing five arguments:
        * `onWorldBounds(sprite, up, down, left, right)`
        * where the Sprite is a reference to the Sprite that owns this Body, and the other arguments are booleans
        * indicating on which side of the world the Body collided.
        * @property {Phaser.Signal} onWorldBounds
        */
        this.onWorldBounds = null;

        /**
        * A Signal that is dispatched when this Body collides with another Body.
        *
        * You still need to call `game.physics.arcade.collide` in your `update` method in order
        * for this signal to be dispatched.
        *
        * Usually you'd pass a callback to the `collide` method, but this signal provides for
        * a different level of notification.
        *
        * Due to the potentially high volume of signals this could create it is disabled by default.
        *
        * To use this feature set this property to a Phaser.Signal: `sprite.body.onCollide = new Phaser.Signal()`
        * and it will be called when a collision happens, passing two arguments: the sprites which collided.
        * The first sprite in the argument is always the owner of this Body.
        *
        * If two Bodies with this Signal set collide, both will dispatch the Signal.
        * @property {Phaser.Signal} onCollide
        */
        this.onCollide = null;

        /**
        * A Signal that is dispatched when this Body overlaps with another Body.
        *
        * You still need to call `game.physics.arcade.overlap` in your `update` method in order
        * for this signal to be dispatched.
        *
        * Usually you'd pass a callback to the `overlap` method, but this signal provides for
        * a different level of notification.
        *
        * Due to the potentially high volume of signals this could create it is disabled by default.
        *
        * To use this feature set this property to a Phaser.Signal: `sprite.body.onOverlap = new Phaser.Signal()`
        * and it will be called when a collision happens, passing two arguments: the sprites which collided.
        * The first sprite in the argument is always the owner of this Body.
        *
        * If two Bodies with this Signal set collide, both will dispatch the Signal.
        * @property {Phaser.Signal} onOverlap
        */
        this.onOverlap = null;

        /**
        * @property {Phaser.Point} maxVelocity - The maximum velocity in pixels per second sq. that the Body can reach.
        * @default
        */
        this.maxVelocity = new Phaser.Point(10000, 10000);

        /**
        * @property {Phaser.Point} friction - The amount of movement that will occur if another object 'rides' this one.
        */
        this.friction = new Phaser.Point(1, 0);

        /**
        * @property {number} angularVelocity - The angular velocity controls the rotation speed of the Body. It is measured in degrees per second.
        * @default
        */
        this.angularVelocity = 0;

        /**
        * @property {number} angularAcceleration - The angular acceleration is the rate of change of the angular velocity. Measured in degrees per second squared.
        * @default
        */
        this.angularAcceleration = 0;

        /**
        * @property {number} angularDrag - The drag applied during the rotation of the Body. Measured in degrees per second squared.
        * @default
        */
        this.angularDrag = 0;

        /**
        * @property {number} maxAngular - The maximum angular velocity in degrees per second that the Body can reach.
        * @default
        */
        this.maxAngular = 1000;

        /**
        * @property {number} mass - The mass of the Body. When two bodies collide their mass is used in the calculation to determine the exchange of velocity.
        * @default
        */
        this.mass = 1;

        /**
        * @property {number} angle - The angle of the Body's velocity in radians.
        * @readonly
        */
        this.angle = 0;

        /**
        * @property {number} speed - The speed of the Body as calculated by its velocity.
        * @readonly
        */
        this.speed = 0;

        /**
        * @property {number} facing - A const reference to the direction the Body is traveling or facing.
        * @default
        */
        this.facing = Phaser.NONE;

        /**
        * @property {boolean} immovable - An immovable Body will not receive any impacts from other bodies.
        * @default
        */
        this.immovable = false;

        /**
        * If you have a Body that is being moved around the world via a tween or a Group motion, but its local x/y position never
        * actually changes, then you should set Body.moves = false. Otherwise it will most likely fly off the screen.
        * If you want the physics system to move the body around, then set moves to true.
        * @property {boolean} moves - Set to true to allow the Physics system to move this Body, otherwise false to move it manually.
        * @default
        */
        this.moves = true;

        /**
        * This flag allows you to disable the custom x separation that takes place by Physics.Arcade.separate.
        * Used in combination with your own collision processHandler you can create whatever type of collision response you need.
        * @property {boolean} customSeparateX - Use a custom separation system or the built-in one?
        * @default
        */
        this.customSeparateX = false;

        /**
        * This flag allows you to disable the custom y separation that takes place by Physics.Arcade.separate.
        * Used in combination with your own collision processHandler you can create whatever type of collision response you need.
        * @property {boolean} customSeparateY - Use a custom separation system or the built-in one?
        * @default
        */
        this.customSeparateY = false;

        /**
        * When this body collides with another, the amount of overlap is stored here.
        * @property {number} overlapX - The amount of horizontal overlap during the collision.
        */
        this.overlapX = 0;

        /**
        * When this body collides with another, the amount of overlap is stored here.
        * @property {number} overlapY - The amount of vertical overlap during the collision.
        */
        this.overlapY = 0;

        /**
        * If `Body.isCircle` is true, and this body collides with another circular body, the amount of overlap is stored here.
        * @property {number} overlapR - The amount of overlap during the collision.
        */
        this.overlapR = 0;

        /**
        * If a body is overlapping with another body, but neither of them are moving (maybe they spawned on-top of each other?) this is set to true.
        * @property {boolean} embedded - Body embed value.
        */
        this.embedded = false;

        /**
        * A Body can be set to collide against the World bounds automatically and rebound back into the World if this is set to true. Otherwise it will leave the World.
        * @property {boolean} collideWorldBounds - Should the Body collide with the World bounds?
        */
        this.collideWorldBounds = false;

        /**
        * Set the checkCollision properties to control which directions collision is processed for this Body.
        * For example checkCollision.up = false means it won't collide when the collision happened while moving up.
        * If you need to disable a Body entirely, use `body.enable = false`, this will also disable motion.
        * If you need to disable just collision and/or overlap checks, but retain motion, set `checkCollision.none = true`.
        * @property {object} checkCollision - An object containing allowed collision.
        */
        this.checkCollision = { none: false, any: true, up: true, down: true, left: true, right: true };

        /**
        * This object is populated with boolean values when the Body collides with another.
        * touching.up = true means the collision happened to the top of this Body for example.
        * @property {object} touching - An object containing touching results.
        */
        this.touching = { none: true, up: false, down: false, left: false, right: false };

        /**
        * This object is populated with previous touching values from the bodies previous collision.
        * @property {object} wasTouching - An object containing previous touching results.
        */
        this.wasTouching = { none: true, up: false, down: false, left: false, right: false };

        /**
        * This object is populated with boolean values when the Body collides with the World bounds or a Tile.
        * For example if blocked.up is true then the Body cannot move up.
        * @property {object} blocked - An object containing on which faces this Body is blocked from moving, if any.
        */
        this.blocked = { up: false, down: false, left: false, right: false };

        /**
        * If this is an especially small or fast moving object then it can sometimes skip over tilemap collisions if it moves through a tile in a step.
        * Set this padding value to add extra padding to its bounds. tilePadding.x applied to its width, y to its height.
        * @property {Phaser.Point} tilePadding - Extra padding to be added to this sprite's dimensions when checking for tile collision.
        */
        this.tilePadding = new Phaser.Point();

        /**
        * @property {boolean} dirty - If this Body in a preUpdate (true) or postUpdate (false) state?
        */
        this.dirty = false;

        /**
        * @property {boolean} skipQuadTree - If true and you collide this Sprite against a Group, it will disable the collision check from using a QuadTree.
        */
        this.skipQuadTree = false;

        /**
        * If true the Body will check itself against the Sprite.getBounds() dimensions and adjust its width and height accordingly.
        * If false it will compare its dimensions against the Sprite scale instead, and adjust its width height if the scale has changed.
        * Typically you would need to enable syncBounds if your sprite is the child of a responsive display object such as a FlexLayer,
        * or in any situation where the Sprite scale doesn't change, but its parents scale is effecting the dimensions regardless.
        * @property {boolean} syncBounds
        * @default
        */
        this.syncBounds = false;

        /**
        * @property {boolean} isMoving - Set by the `moveTo` and `moveFrom` methods.
        */
        this.isMoving = false;

        /**
        * @property {boolean} stopVelocityOnCollide - Set by the `moveTo` and `moveFrom` methods.
        */
        this.stopVelocityOnCollide = true;

        /**
        * @property {integer} moveTimer - Internal time used by the `moveTo` and `moveFrom` methods.
        * @private
        */
        this.moveTimer = 0;

        /**
        * @property {integer} moveDistance - Internal distance value, used by the `moveTo` and `moveFrom` methods.
        * @private
        */
        this.moveDistance = 0;

        /**
        * @property {integer} moveDuration - Internal duration value, used by the `moveTo` and `moveFrom` methods.
        * @private
        */
        this.moveDuration = 0;

        /**
        * @property {Phaser.Line} moveTarget - Set by the `moveTo` method, and updated each frame.
        * @private
        */
        this.moveTarget = null;

        /**
        * @property {Phaser.Point} moveEnd - Set by the `moveTo` method, and updated each frame.
        * @private
        */
        this.moveEnd = null;

        /**
        * @property {Phaser.Signal} onMoveComplete - Listen for the completion of `moveTo` or `moveFrom` events.
        */
        this.onMoveComplete = new Phaser.Signal();

        /**
        * @property {function} movementCallback - Optional callback. If set, invoked during the running of `moveTo` or `moveFrom` events.
        */
        this.movementCallback = null;

        /**
        * @property {object} movementCallbackContext - Context in which to call the movementCallback.
        */
        this.movementCallbackContext = null;

        /**
        * @property {boolean} _reset - Internal cache var.
        * @private
        */
        this._reset = true;

        /**
        * @property {number} _sx - Internal cache var.
        * @private
        */
        this._sx = sprite.scale.x;

        /**
        * @property {number} _sy - Internal cache var.
        * @private
        */
        this._sy = sprite.scale.y;

        /**
        * @property {number} _dx - Internal cache var.
        * @private
        */
        this._dx = 0;

        /**
        * @property {number} _dy - Internal cache var.
        * @private
        */
        this._dy = 0;

    };

    Phaser.Physics.Arcade.Body.prototype = {

        /**
        * Internal method.
        *
        * @method Phaser.Physics.Arcade.Body#updateBounds
        * @protected
        */
        updateBounds: function () {

            if (this.syncBounds)
            {
                var b = this.sprite.getBounds();
                b.ceilAll();

                if (b.width !== this.width || b.height !== this.height)
                {
                    this.width = b.width;
                    this.height = b.height;
                    this._reset = true;
                }
            }
            else
            {
                var asx = Math.abs(this.sprite.scale.x);
                var asy = Math.abs(this.sprite.scale.y);

                if (asx !== this._sx || asy !== this._sy)
                {
                    this.width = this.sourceWidth * asx;
                    this.height = this.sourceHeight * asy;
                    this._sx = asx;
                    this._sy = asy;
                    this._reset = true;
                }
            }

            if (this._reset)
            {
                this.halfWidth = Math.floor(this.width / 2);
                this.halfHeight = Math.floor(this.height / 2);
                this.center.setTo(this.position.x + this.halfWidth, this.position.y + this.halfHeight);
            }

        },

        /**
        * Internal method.
        *
        * @method Phaser.Physics.Arcade.Body#preUpdate
        * @protected
        */
        preUpdate: function () {

            if (!this.enable || this.game.physics.arcade.isPaused)
            {
                return;
            }

            this.dirty = true;

            //  Store and reset collision flags
            this.wasTouching.none = this.touching.none;
            this.wasTouching.up = this.touching.up;
            this.wasTouching.down = this.touching.down;
            this.wasTouching.left = this.touching.left;
            this.wasTouching.right = this.touching.right;

            this.touching.none = true;
            this.touching.up = false;
            this.touching.down = false;
            this.touching.left = false;
            this.touching.right = false;

            this.blocked.up = false;
            this.blocked.down = false;
            this.blocked.left = false;
            this.blocked.right = false;

            this.embedded = false;

            this.updateBounds();

            this.position.x = (this.sprite.world.x - (this.sprite.anchor.x * this.sprite.width)) + this.sprite.scale.x * this.offset.x;
            this.position.x -= this.sprite.scale.x < 0 ? this.width : 0;

            this.position.y = (this.sprite.world.y - (this.sprite.anchor.y * this.sprite.height)) + this.sprite.scale.y * this.offset.y;
            this.position.y -= this.sprite.scale.y < 0 ? this.height : 0;

            this.rotation = this.sprite.angle;

            this.preRotation = this.rotation;

            if (this._reset || this.sprite.fresh)
            {
                this.prev.x = this.position.x;
                this.prev.y = this.position.y;
            }

            if (this.moves)
            {
                this.game.physics.arcade.updateMotion(this);

                this.newVelocity.set(this.velocity.x * this.game.time.physicsElapsed, this.velocity.y * this.game.time.physicsElapsed);

                this.position.x += this.newVelocity.x;
                this.position.y += this.newVelocity.y;

                if (this.position.x !== this.prev.x || this.position.y !== this.prev.y)
                {
                    this.angle = Math.atan2(this.velocity.y, this.velocity.x);
                }

                this.speed = Math.sqrt(this.velocity.x * this.velocity.x + this.velocity.y * this.velocity.y);

                //  Now the State update will throw collision checks at the Body
                //  And finally we'll integrate the new position back to the Sprite in postUpdate

                if (this.collideWorldBounds)
                {
                    if (this.checkWorldBounds() && this.onWorldBounds)
                    {
                        this.onWorldBounds.dispatch(this.sprite, this.blocked.up, this.blocked.down, this.blocked.left, this.blocked.right);
                    }
                }
            }

            this._dx = this.deltaX();
            this._dy = this.deltaY();

            this._reset = false;

        },

        /**
        * Internal method.
        *
        * @method Phaser.Physics.Arcade.Body#updateMovement
        * @protected
        */
        updateMovement: function () {

            var percent = 0;
            var collided = (this.overlapX !== 0 || this.overlapY !== 0);

            //  Duration or Distance based?

            if (this.moveDuration > 0)
            {
                this.moveTimer += this.game.time.elapsedMS;

                percent = this.moveTimer / this.moveDuration;
            }
            else
            {
                this.moveTarget.end.set(this.position.x, this.position.y);

                percent = this.moveTarget.length / this.moveDistance;
            }

            if (this.movementCallback)
            {
                var result = this.movementCallback.call(this.movementCallbackContext, this, this.velocity, percent);
            }

            if (collided || percent >= 1 || (result !== undefined && result !== true))
            {
                this.stopMovement((percent >= 1) || (this.stopVelocityOnCollide && collided));
                return false;
            }

            return true;

        },

        /**
        * If this Body is moving as a result of a call to `moveTo` or `moveFrom` (i.e. it
        * has Body.isMoving true), then calling this method will stop the movement before
        * either the duration or distance counters expire.
        *
        * The `onMoveComplete` signal is dispatched.
        *
        * @method Phaser.Physics.Arcade.Body#stopMovement
        * @param {boolean} [stopVelocity] - Should the Body.velocity be set to zero?
        */
        stopMovement: function (stopVelocity) {

            if (this.isMoving)
            {
                this.isMoving = false;

                if (stopVelocity)
                {
                    this.velocity.set(0);
                }

                //  Send the Sprite this Body belongs to
                //  and a boolean indicating if it stopped because of a collision or not
                this.onMoveComplete.dispatch(this.sprite, (this.overlapX !== 0 || this.overlapY !== 0));
            }

        },

        /**
        * Internal method.
        *
        * @method Phaser.Physics.Arcade.Body#postUpdate
        * @protected
        */
        postUpdate: function () {

            //  Only allow postUpdate to be called once per frame
            if (!this.enable || !this.dirty)
            {
                return;
            }

            //  Moving?
            if (this.isMoving)
            {
                this.updateMovement();
            }

            this.dirty = false;

            if (this.deltaX() < 0)
            {
                this.facing = Phaser.LEFT;
            }
            else if (this.deltaX() > 0)
            {
                this.facing = Phaser.RIGHT;
            }

            if (this.deltaY() < 0)
            {
                this.facing = Phaser.UP;
            }
            else if (this.deltaY() > 0)
            {
                this.facing = Phaser.DOWN;
            }

            if (this.moves)
            {
                this._dx = this.deltaX();
                this._dy = this.deltaY();

                if (this.deltaMax.x !== 0 && this._dx !== 0)
                {
                    if (this._dx < 0 && this._dx < -this.deltaMax.x)
                    {
                        this._dx = -this.deltaMax.x;
                    }
                    else if (this._dx > 0 && this._dx > this.deltaMax.x)
                    {
                        this._dx = this.deltaMax.x;
                    }
                }

                if (this.deltaMax.y !== 0 && this._dy !== 0)
                {
                    if (this._dy < 0 && this._dy < -this.deltaMax.y)
                    {
                        this._dy = -this.deltaMax.y;
                    }
                    else if (this._dy > 0 && this._dy > this.deltaMax.y)
                    {
                        this._dy = this.deltaMax.y;
                    }
                }

                this.sprite.position.x += this._dx;
                this.sprite.position.y += this._dy;
                this._reset = true;
            }

            this.center.setTo(this.position.x + this.halfWidth, this.position.y + this.halfHeight);

            if (this.allowRotation)
            {
                this.sprite.angle += this.deltaZ();
            }

            this.prev.x = this.position.x;
            this.prev.y = this.position.y;

        },

        /**
        * Internal method.
        *
        * @method Phaser.Physics.Arcade.Body#checkWorldBounds
        * @protected
        * @return {boolean} True if the Body collided with the world bounds, otherwise false.
        */
        checkWorldBounds: function () {

            var pos = this.position;
            var bounds = this.game.physics.arcade.bounds;
            var check = this.game.physics.arcade.checkCollision;

            var bx = (this.worldBounce) ? -this.worldBounce.x : -this.bounce.x;
            var by = (this.worldBounce) ? -this.worldBounce.y : -this.bounce.y;

            if (this.isCircle)
            {
                var bodyBounds = {
                    x: this.center.x - this.radius,
                    y: this.center.y - this.radius,
                    right: this.center.x + this.radius,
                    bottom: this.center.y + this.radius
                };

                if (bodyBounds.x < bounds.x && check.left)
                {
                    pos.x = bounds.x - this.halfWidth + this.radius;
                    this.velocity.x *= bx;
                    this.blocked.left = true;
                }
                else if (bodyBounds.right > bounds.right && check.right)
                {
                    pos.x = bounds.right - this.halfWidth - this.radius;
                    this.velocity.x *= bx;
                    this.blocked.right = true;
                }

                if (bodyBounds.y < bounds.y && check.up)
                {
                    pos.y = bounds.y - this.halfHeight + this.radius;
                    this.velocity.y *= by;
                    this.blocked.up = true;
                }
                else if (bodyBounds.bottom > bounds.bottom && check.down)
                {
                    pos.y = bounds.bottom  - this.halfHeight - this.radius;
                    this.velocity.y *= by;
                    this.blocked.down = true;
                }
            }
            else
            {
                if (pos.x < bounds.x && check.left)
                {
                    pos.x = bounds.x;
                    this.velocity.x *= bx;
                    this.blocked.left = true;
                }
                else if (this.right > bounds.right && check.right)
                {
                    pos.x = bounds.right - this.width;
                    this.velocity.x *= bx;
                    this.blocked.right = true;
                }

                if (pos.y < bounds.y && check.up)
                {
                    pos.y = bounds.y;
                    this.velocity.y *= by;
                    this.blocked.up = true;
                }
                else if (this.bottom > bounds.bottom && check.down)
                {
                    pos.y = bounds.bottom - this.height;
                    this.velocity.y *= by;
                    this.blocked.down = true;
                }
            }

            return (this.blocked.up || this.blocked.down || this.blocked.left || this.blocked.right);

        },

        /**
        * Note: This method is experimental, and may be changed or removed in a future release.
        *
        * This method moves the Body in the given direction, for the duration specified.
        * It works by setting the velocity on the Body, and an internal timer, and then
        * monitoring the duration each frame. When the duration is up the movement is
        * stopped and the `Body.onMoveComplete` signal is dispatched.
        *
        * Movement also stops if the Body collides or overlaps with any other Body.
        *
        * You can control if the velocity should be reset to zero on collision, by using
        * the property `Body.stopVelocityOnCollide`.
        *
        * Stop the movement at any time by calling `Body.stopMovement`.
        *
        * You can optionally set a speed in pixels per second. If not specified it
        * will use the current `Body.speed` value. If this is zero, the function will return false.
        *
        * Please note that due to browser timings you should allow for a variance in
        * when the duration will actually expire. Depending on system it may be as much as
        * +- 50ms. Also this method doesn't take into consideration any other forces acting
        * on the Body, such as Gravity, drag or maxVelocity, all of which may impact the
        * movement.
        *
        * @method Phaser.Physics.Arcade.Body#moveFrom
        * @param  {integer} duration  - The duration of the movement, in ms.
        * @param  {integer} [speed] - The speed of the movement, in pixels per second. If not provided `Body.speed` is used.
        * @param  {integer} [direction] - The angle of movement. If not provided `Body.angle` is used.
        * @return {boolean} True if the movement successfully started, otherwise false.
        */
        moveFrom: function (duration, speed, direction) {

            if (speed === undefined) { speed = this.speed; }

            if (speed === 0)
            {
                return false;
            }

            var angle;

            if (direction === undefined)
            {
                angle = this.angle;
                direction = this.game.math.radToDeg(angle);
            }
            else
            {
                angle = this.game.math.degToRad(direction);
            }

            this.moveTimer = 0;
            this.moveDuration = duration;

            //  Avoid sin/cos
            if (direction === 0 || direction === 180)
            {
                this.velocity.set(Math.cos(angle) * speed, 0);
            }
            else if (direction === 90 || direction === 270)
            {
                this.velocity.set(0, Math.sin(angle) * speed);
            }
            else
            {
                this.velocity.set(Math.cos(angle) * speed, Math.sin(angle) * speed);
            }

            this.isMoving = true;

            return true;

        },

        /**
        * Note: This method is experimental, and may be changed or removed in a future release.
        *
        * This method moves the Body in the given direction, for the duration specified.
        * It works by setting the velocity on the Body, and an internal distance counter.
        * The distance is monitored each frame. When the distance equals the distance
        * specified in this call, the movement is stopped, and the `Body.onMoveComplete`
        * signal is dispatched.
        *
        * Movement also stops if the Body collides or overlaps with any other Body.
        *
        * You can control if the velocity should be reset to zero on collision, by using
        * the property `Body.stopVelocityOnCollide`.
        *
        * Stop the movement at any time by calling `Body.stopMovement`.
        *
        * Please note that due to browser timings you should allow for a variance in
        * when the distance will actually expire.
        *
        * Note: This method doesn't take into consideration any other forces acting
        * on the Body, such as Gravity, drag or maxVelocity, all of which may impact the
        * movement.
        *
        * @method Phaser.Physics.Arcade.Body#moveTo
        * @param  {integer} duration - The duration of the movement, in ms.
        * @param  {integer} distance - The distance, in pixels, the Body will move.
        * @param  {integer} [direction] - The angle of movement. If not provided `Body.angle` is used.
        * @return {boolean} True if the movement successfully started, otherwise false.
        */
        moveTo: function (duration, distance, direction) {

            var speed = distance / (duration / 1000);

            if (speed === 0)
            {
                return false;
            }

            var angle;

            if (direction === undefined)
            {
                angle = this.angle;
                direction = this.game.math.radToDeg(angle);
            }
            else
            {
                angle = this.game.math.degToRad(direction);
            }

            distance = Math.abs(distance);

            this.moveDuration = 0;
            this.moveDistance = distance;

            if (this.moveTarget === null)
            {
                this.moveTarget = new Phaser.Line();
                this.moveEnd = new Phaser.Point();
            }

            this.moveTarget.fromAngle(this.x, this.y, angle, distance);

            this.moveEnd.set(this.moveTarget.end.x, this.moveTarget.end.y);

            this.moveTarget.setTo(this.x, this.y, this.x, this.y);

            //  Avoid sin/cos
            if (direction === 0 || direction === 180)
            {
                this.velocity.set(Math.cos(angle) * speed, 0);
            }
            else if (direction === 90 || direction === 270)
            {
                this.velocity.set(0, Math.sin(angle) * speed);
            }
            else
            {
                this.velocity.set(Math.cos(angle) * speed, Math.sin(angle) * speed);
            }

            this.isMoving = true;

            return true;

        },

        /**
        * You can modify the size of the physics Body to be any dimension you need.
        * This allows you to make it smaller, or larger, than the parent Sprite.
        * You can also control the x and y offset of the Body. This is the position of the
        * Body relative to the top-left of the Sprite _texture_.
        *
        * For example: If you have a Sprite with a texture that is 80x100 in size,
        * and you want the physics body to be 32x32 pixels in the middle of the texture, you would do:
        *
        * `setSize(32, 32, 24, 34)`
        *
        * Where the first two parameters is the new Body size (32x32 pixels).
        * 24 is the horizontal offset of the Body from the top-left of the Sprites texture, and 34
        * is the vertical offset.
        *
        * Calling `setSize` on a Body that has already had `setCircle` will reset all of the Circle
        * properties, making this Body rectangular again.
        *
        * @method Phaser.Physics.Arcade.Body#setSize
        * @param {number} width - The width of the Body.
        * @param {number} height - The height of the Body.
        * @param {number} [offsetX] - The X offset of the Body from the top-left of the Sprites texture.
        * @param {number} [offsetY] - The Y offset of the Body from the top-left of the Sprites texture.
        */
        setSize: function (width, height, offsetX, offsetY) {

            if (offsetX === undefined) { offsetX = this.offset.x; }
            if (offsetY === undefined) { offsetY = this.offset.y; }

            this.sourceWidth = width;
            this.sourceHeight = height;
            this.width = this.sourceWidth * this._sx;
            this.height = this.sourceHeight * this._sy;
            this.halfWidth = Math.floor(this.width / 2);
            this.halfHeight = Math.floor(this.height / 2);
            this.offset.setTo(offsetX, offsetY);

            this.center.setTo(this.position.x + this.halfWidth, this.position.y + this.halfHeight);

            this.isCircle = false;
            this.radius = 0;

        },

        /**
        * Sets this Body as using a circle, of the given radius, for all collision detection instead of a rectangle.
        * The radius is given in pixels and is the distance from the center of the circle to the edge.
        *
        * You can also control the x and y offset, which is the position of the Body relative to the top-left of the Sprite.
        *
        * To change a Body back to being rectangular again call `Body.setSize`.
        *
        * Note: Circular collision only happens with other Arcade Physics bodies, it does not
        * work against tile maps, where rectangular collision is the only method supported.
        *
        * @method Phaser.Physics.Arcade.Body#setCircle
        * @param {number} [radius] - The radius of the Body in pixels. Pass a value of zero / undefined, to stop the Body using a circle for collision.
        * @param {number} [offsetX] - The X offset of the Body from the Sprite position.
        * @param {number} [offsetY] - The Y offset of the Body from the Sprite position.
        */
        setCircle: function (radius, offsetX, offsetY) {

            if (offsetX === undefined) { offsetX = this.offset.x; }
            if (offsetY === undefined) { offsetY = this.offset.y; }

            if (radius > 0)
            {
                this.isCircle = true;
                this.radius = radius;

                this.sourceWidth = radius * 2;
                this.sourceHeight = radius * 2;

                this.width = this.sourceWidth * this._sx;
                this.height = this.sourceHeight * this._sy;

                this.halfWidth = Math.floor(this.width / 2);
                this.halfHeight = Math.floor(this.height / 2);

                this.offset.setTo(offsetX, offsetY);

                this.center.setTo(this.position.x + this.halfWidth, this.position.y + this.halfHeight);
            }
            else
            {
                this.isCircle = false;
            }

        },

        /**
        * Resets all Body values (velocity, acceleration, rotation, etc)
        *
        * @method Phaser.Physics.Arcade.Body#reset
        * @param {number} x - The new x position of the Body.
        * @param {number} y - The new y position of the Body.
        */
        reset: function (x, y) {

            this.velocity.set(0);
            this.acceleration.set(0);

            this.speed = 0;
            this.angularVelocity = 0;
            this.angularAcceleration = 0;

            this.position.x = (x - (this.sprite.anchor.x * this.sprite.width)) + this.sprite.scale.x * this.offset.x;
            this.position.x -= this.sprite.scale.x < 0 ? this.width : 0;

            this.position.y = (y - (this.sprite.anchor.y * this.sprite.height)) + this.sprite.scale.y * this.offset.y;
            this.position.y -= this.sprite.scale.y < 0 ? this.height : 0;

            this.prev.x = this.position.x;
            this.prev.y = this.position.y;

            this.rotation = this.sprite.angle;
            this.preRotation = this.rotation;

            this._sx = this.sprite.scale.x;
            this._sy = this.sprite.scale.y;

            this.center.setTo(this.position.x + this.halfWidth, this.position.y + this.halfHeight);

        },

        /**
        * Returns the bounds of this physics body.
        *
        * Only used internally by the World collision methods.
        *
        * @method Phaser.Physics.Arcade.Body#getBounds
        * @param {object} obj - The object in which to set the bounds values.
        * @return {object} The object that was given to this method.
        */
        getBounds: function (obj) {

            if (this.isCircle)
            {
                obj.x = this.center.x - this.radius;
                obj.y = this.center.y - this.radius;
                obj.right = this.center.x + this.radius;
                obj.bottom = this.center.y + this.radius;
            }
            else
            {
                obj.x = this.x;
                obj.y = this.y;
                obj.right = this.right;
                obj.bottom = this.bottom;
            }

            return obj;

        },

        /**
        * Tests if a world point lies within this Body.
        *
        * @method Phaser.Physics.Arcade.Body#hitTest
        * @param {number} x - The world x coordinate to test.
        * @param {number} y - The world y coordinate to test.
        * @return {boolean} True if the given coordinates are inside this Body, otherwise false.
        */
        hitTest: function (x, y) {

            return (this.isCircle) ? Phaser.Circle.contains(this, x, y) : Phaser.Rectangle.contains(this, x, y);

        },

        /**
        * Returns true if the bottom of this Body is in contact with either the world bounds or a tile.
        *
        * @method Phaser.Physics.Arcade.Body#onFloor
        * @return {boolean} True if in contact with either the world bounds or a tile.
        */
        onFloor: function () {

            return this.blocked.down;

        },

        /**
        * Returns true if the top of this Body is in contact with either the world bounds or a tile.
        *
        * @method Phaser.Physics.Arcade.Body#onCeiling
        * @return {boolean} True if in contact with either the world bounds or a tile.
        */
        onCeiling: function(){

            return this.blocked.up;

        },

        /**
        * Returns true if either side of this Body is in contact with either the world bounds or a tile.
        *
        * @method Phaser.Physics.Arcade.Body#onWall
        * @return {boolean} True if in contact with either the world bounds or a tile.
        */
        onWall: function () {

            return (this.blocked.left || this.blocked.right);

        },

        /**
        * Returns the absolute delta x value.
        *
        * @method Phaser.Physics.Arcade.Body#deltaAbsX
        * @return {number} The absolute delta value.
        */
        deltaAbsX: function () {

            return (this.deltaX() > 0 ? this.deltaX() : -this.deltaX());

        },

        /**
        * Returns the absolute delta y value.
        *
        * @method Phaser.Physics.Arcade.Body#deltaAbsY
        * @return {number} The absolute delta value.
        */
        deltaAbsY: function () {

            return (this.deltaY() > 0 ? this.deltaY() : -this.deltaY());

        },

        /**
        * Returns the delta x value. The difference between Body.x now and in the previous step.
        *
        * @method Phaser.Physics.Arcade.Body#deltaX
        * @return {number} The delta value. Positive if the motion was to the right, negative if to the left.
        */
        deltaX: function () {

            return this.position.x - this.prev.x;

        },

        /**
        * Returns the delta y value. The difference between Body.y now and in the previous step.
        *
        * @method Phaser.Physics.Arcade.Body#deltaY
        * @return {number} The delta value. Positive if the motion was downwards, negative if upwards.
        */
        deltaY: function () {

            return this.position.y - this.prev.y;

        },

        /**
        * Returns the delta z value. The difference between Body.rotation now and in the previous step.
        *
        * @method Phaser.Physics.Arcade.Body#deltaZ
        * @return {number} The delta value. Positive if the motion was clockwise, negative if anti-clockwise.
        */
        deltaZ: function () {

            return this.rotation - this.preRotation;

        },

        /**
        * Destroys this Body.
        *
        * First it calls Group.removeFromHash if the Game Object this Body belongs to is part of a Group.
        * Then it nulls the Game Objects body reference, and nulls this Body.sprite reference.
        *
        * @method Phaser.Physics.Arcade.Body#destroy
        */
        destroy: function () {

            if (this.sprite.parent && this.sprite.parent instanceof Phaser.Group)
            {
                this.sprite.parent.removeFromHash(this.sprite);
            }

            this.sprite.body = null;
            this.sprite = null;

        }

    };

    /**
    * @name Phaser.Physics.Arcade.Body#left
    * @property {number} left - The x position of the Body. The same as `Body.x`.
    */
    Object.defineProperty(Phaser.Physics.Arcade.Body.prototype, "left", {

        get: function () {

            return this.position.x;

        }

    });

    /**
    * @name Phaser.Physics.Arcade.Body#right
    * @property {number} right - The right value of this Body (same as Body.x + Body.width)
    * @readonly
    */
    Object.defineProperty(Phaser.Physics.Arcade.Body.prototype, "right", {

        get: function () {

            return this.position.x + this.width;

        }

    });

    /**
    * @name Phaser.Physics.Arcade.Body#top
    * @property {number} top - The y position of the Body. The same as `Body.y`.
    */
    Object.defineProperty(Phaser.Physics.Arcade.Body.prototype, "top", {

        get: function () {

            return this.position.y;

        }

    });

    /**
    * @name Phaser.Physics.Arcade.Body#bottom
    * @property {number} bottom - The bottom value of this Body (same as Body.y + Body.height)
    * @readonly
    */
    Object.defineProperty(Phaser.Physics.Arcade.Body.prototype, "bottom", {

        get: function () {

            return this.position.y + this.height;

        }

    });

    /**
    * @name Phaser.Physics.Arcade.Body#x
    * @property {number} x - The x position.
    */
    Object.defineProperty(Phaser.Physics.Arcade.Body.prototype, "x", {

        get: function () {

            return this.position.x;

        },

        set: function (value) {

            this.position.x = value;
        }

    });

    /**
    * @name Phaser.Physics.Arcade.Body#y
    * @property {number} y - The y position.
    */
    Object.defineProperty(Phaser.Physics.Arcade.Body.prototype, "y", {

        get: function () {

            return this.position.y;

        },

        set: function (value) {

            this.position.y = value;

        }

    });

    /**
    * Render Sprite Body.
    *
    * @method Phaser.Physics.Arcade.Body#render
    * @param {object} context - The context to render to.
    * @param {Phaser.Physics.Arcade.Body} body - The Body to render the info of.
    * @param {string} [color='rgba(0,255,0,0.4)'] - color of the debug info to be rendered. (format is css color string).
    * @param {boolean} [filled=true] - Render the objected as a filled (default, true) or a stroked (false)
    */
    Phaser.Physics.Arcade.Body.render = function (context, body, color, filled) {

        if (filled === undefined) { filled = true; }

        color = color || 'rgba(0,255,0,0.4)';

        context.fillStyle = color;
        context.strokeStyle = color;

        if (body.isCircle)
        {
            context.beginPath();
            context.arc(body.center.x - body.game.camera.x, body.center.y - body.game.camera.y, body.radius, 0, 2 * Math.PI);

            if (filled)
            {
                context.fill();
            }
            else
            {
                context.stroke();
            }
        }
        else
        {
            if (filled)
            {
                context.fillRect(body.position.x - body.game.camera.x, body.position.y - body.game.camera.y, body.width, body.height);
            }
            else
            {
                context.strokeRect(body.position.x - body.game.camera.x, body.position.y - body.game.camera.y, body.width, body.height);
            }
        }

    };

    /**
    * Render Sprite Body Physics Data as text.
    *
    * @method Phaser.Physics.Arcade.Body#renderBodyInfo
    * @param {Phaser.Physics.Arcade.Body} body - The Body to render the info of.
    * @param {number} x - X position of the debug info to be rendered.
    * @param {number} y - Y position of the debug info to be rendered.
    * @param {string} [color='rgb(255,255,255)'] - color of the debug info to be rendered. (format is css color string).
    */
    Phaser.Physics.Arcade.Body.renderBodyInfo = function (debug, body) {

        debug.line('x: ' + body.x.toFixed(2), 'y: ' + body.y.toFixed(2), 'width: ' + body.width, 'height: ' + body.height);
        debug.line('velocity x: ' + body.velocity.x.toFixed(2), 'y: ' + body.velocity.y.toFixed(2), 'deltaX: ' + body._dx.toFixed(2), 'deltaY: ' + body._dy.toFixed(2));
        debug.line('acceleration x: ' + body.acceleration.x.toFixed(2), 'y: ' + body.acceleration.y.toFixed(2), 'speed: ' + body.speed.toFixed(2), 'angle: ' + body.angle.toFixed(2));
        debug.line('gravity x: ' + body.gravity.x, 'y: ' + body.gravity.y, 'bounce x: ' + body.bounce.x.toFixed(2), 'y: ' + body.bounce.y.toFixed(2));
        debug.line('touching left: ' + body.touching.left, 'right: ' + body.touching.right, 'up: ' + body.touching.up, 'down: ' + body.touching.down);
        debug.line('blocked left: ' + body.blocked.left, 'right: ' + body.blocked.right, 'up: ' + body.blocked.up, 'down: ' + body.blocked.down);

    };

    Phaser.Physics.Arcade.Body.prototype.constructor = Phaser.Physics.Arcade.Body;