phaser/src/physics/arcade/Body.js

/**
* @author       Richard Davey <rich@photonstorm.com>
* @copyright    2014 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
* @classdesc Arcade Physics Body Constructor
* @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 {Phaser.Point} offset - The offset of the Physics Body from the Sprite x/y position.
    */
    // this.offset = new Phaser.Point(-(sprite.anchor.x * sprite.width), -(sprite.anchor.y * sprite.height));
    this.offset = new Phaser.Point();

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

    /**
    * @property {number} rotation - The amount the Body is rotated.
    */
    this.rotation = sprite.rotation;

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

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

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

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

    /**
    * @property .numInternal ID cache
    */
    this.height = sprite.height;

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

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

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

    /**
    * @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 {Phaser.Point} velocity - The velocity in pixels per second sq. of the Body.
    */
    this.velocity = new Phaser.Point();

    /**
    * @property {Phaser.Point} newVelocity - New velocity.
    * @readonly
    */
    this.newVelocity = new Phaser.Point(0, 0);

    /**
    * @property {Phaser.Point} acceleration - The velocity in pixels per second sq. of the Body.
    */
    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(0, 0);

    /**
    * @property {Phaser.Point} gravityScale - Gravity scaling factor. This is only applied to world gravity, not local gravity. If you want the body to ignore gravity, set this to zero. If you want to reverse gravity, set it to -1.
    */
    this.gravityScale = new Phaser.Point(1, 1);

    /**
    * @property {Phaser.Point} bounce - The elasticitiy 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();

    /**
    * @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 {number} angularVelocity - The angular velocity in pixels per second sq. of the Body.
    * @default
    */
    this.angularVelocity = 0;

    /**
    * @property {number} angularAcceleration - The angular acceleration in pixels per second sq. of the Body.
    * @default
    */
    this.angularAcceleration = 0;

    /**
    * @property {number} angularDrag - The angular drag applied to the rotation of the Body.
    * @default
    */
    this.angularDrag = 0;

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

    /**
    * @property {number} mass - The mass of the Body.
    * @default
    */
    this.mass = 1;

    /**
    * @property {number} angle - The angle of the Body in radians as calculated by its velocity, rather than its visual angle.
    * @readonly
    */
    this.angle = 0;

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

    /**
    * @property {boolean} skipQuadTree - If the Body is an irregular shape you can set this to true to avoid it being added to any QuadTrees.
    * @default
    */
    this.skipQuadTree = false;

    /**
    * @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;

    /**
    * @property {boolean} moves - Set to true to allow the Physics system to move this Body, other 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 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.
    * @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 };

};

Phaser.Physics.Arcade.Body.prototype = {

    /**
    * Internal method.
    *
    * @method Phaser.Physics.Arcade#updateBounds
    * @protected
    */
    updateBounds: function (centerX, centerY, scaleX, scaleY) {

        if (scaleX != this._sx || scaleY != this._sy)
        {
            this.width = this.sourceWidth * scaleX;
            this.height = this.sourceHeight * scaleY;
            this.halfWidth = Math.floor(this.width / 2);
            this.halfHeight = Math.floor(this.height / 2);
            this._sx = scaleX;
            this._sy = scaleY;
            this.center.setTo(this.x + this.halfWidth, this.y + this.halfHeight);
        }

    },

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

        //  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.embedded = false;

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

        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.speed = Math.sqrt(this.velocity.x * this.velocity.x + this.velocity.y * this.velocity.y);
                this.angle = Math.atan2(this.velocity.y, this.velocity.x);
            }

            //  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)
            {
                this.checkWorldBounds();
            }
        }

    },

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

        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.deltaX() !== 0 || this.deltaY() !== 0)
        {
            // this.sprite.position.x = this.position.x;
            // this.sprite.position.y = this.position.y;
            this.sprite.x += this.deltaX();
            this.sprite.y += this.deltaY();
            this.center.setTo(this.x + this.halfWidth, this.y + this.halfHeight);
        }

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

        this.prev.set(this.position.x, this.position.y);
        this.preRotation = this.rotation;

    },

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

        if (this.x < this.game.world.bounds.x)
        {
            this.x = this.game.world.bounds.x;
            this.velocity.x *= -this.bounce.x;
        }
        else if (this.right > this.game.world.bounds.right)
        {
            this.x = this.game.world.bounds.right - this.width;
            this.velocity.x *= -this.bounce.x;
        }

        if (this.y < this.game.world.bounds.y)
        {
            this.y = this.game.world.bounds.y;
            this.velocity.y *= -this.bounce.y;
        }
        else if (this.bottom > this.game.world.bounds.bottom)
        {
            this.y = this.game.world.bounds.bottom - this.height;
            this.velocity.y *= -this.bounce.y;
        }

    },

    /**
    * You can modify the size of the physics Body to be any dimension you need.
    * So it could be smaller or larger than the parent Sprite. You can also control the x and y offset, which
    * is the position of the Body relative to the top-left of the Sprite.
    *
    * @method Phaser.Physics.Arcade#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 Sprite position.
    * @param {number} offsetY - The Y offset of the Body from the Sprite position.
    */
    setSize: function (width, height, offsetX, offsetY) {

        offsetX = offsetX || this.offset.x;
        offsetY = 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.x + this.halfWidth, this.y + this.halfHeight);

    },

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

        this.velocity.setTo(0, 0);
        this.acceleration.setTo(0, 0);

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

        this.position.set(x, y);
        this.prev.set(x, y);
        this.rotation = this.sprite.rotation;
        this.preRotation = this.rotation;
        
        this.center.setTo(this.x + this.halfWidth, this.y + this.halfHeight);

    },

    /**
    * 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;
    }

};

/**
* @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#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#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#renderDebug
* @param {object} context - The context to render to.
* @param {Phaser.Physics.Arcade.Body} body - The Body to render the info of.
* @param {string} [color='rgb(255,255,255)'] - 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, filled, color) {

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

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

    if (filled)
    {
        context.fillStyle = color;
        context.fillRect(body.position.x - body.game.camera.x, body.position.y - body.game.camera.y, body.width, body.height);
    }
    else
    {
        context.strokeStyle = color;
        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.deltaX().toFixed(2), 'deltaY: ' + body.deltaY().toFixed(2));
    debug.line('velocity x: ' + body.velocity.x.toFixed(2), 'y: ' + body.velocity.y.toFixed(2));
    debug.line('acceleration x: ' + body.acceleration.x.toFixed(2), 'y: ' + body.acceleration.y.toFixed(2));
    // debug.line('gravity x: ' + body.gravity.x, 'y: ' + body.gravity.y, 'world gravity x: ' + this.game.physics.gravity.x, 'y: ' + this.game.physics.gravity.y);
    debug.line('gravity x: ' + body.gravity.x, 'y: ' + body.gravity.y);
    debug.line('bounce x: ' + body.bounce.x.toFixed(2), 'y: ' + body.bounce.y.toFixed(2));
    debug.line('speed: ' + body.speed.toFixed(2), 'angle: ' + body.angle.toFixed(2));
    debug.line('touching left: ' + body.touching.left, 'right: ' + body.touching.right, 'up: ' + body.touching.up, 'down: ' + body.touching.down);

}

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