phaser
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A fast, free and fun HTML5 Game Framework for Desktop and Mobile web browsers from the team at Phaser Studio Inc.
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JavaScript
/**
* @author Jason Nicholls <nicholls.jason@gmail.com>
* @copyright 2018 Photon Storm Ltd.
* @license {@link https://github.com/photonstorm/phaser/blob/master/license.txt|MIT License}
*/
var Clamp = require('../../../math/Clamp');
var Class = require('../../../utils/Class');
var Events = require('../events');
var EaseMap = require('../../../math/easing/EaseMap');
var WrapAngle = require('../../../math/angle/Wrap');
/**
* @classdesc
* A Camera Rotate effect that smoothly rotates the Camera to a target angle over a specified duration.
*
* This effect will rotate the Camera so that its viewport finishes at the given angle in radians,
* over the duration and with the ease specified.
*
* Camera rotation always takes place based on the Camera viewport. By default, rotation happens
* in the center of the viewport. You can adjust this with the `originX` and `originY` properties.
*
* Rotation influences the rendering of _all_ Game Objects visible by this Camera. However, it does not
* rotate the Camera viewport itself, which always remains an axis-aligned rectangle.
*
* Only the camera is rotated. None of the objects it is displaying are impacted, i.e. their positions do
* not change.
*
* The effect will dispatch several events on the Camera itself and you can also specify an `onUpdate` callback,
* which is invoked each frame for the duration of the effect if required.
*
* @class RotateTo
* @memberof Phaser.Cameras.Scene2D.Effects
* @constructor
* @since 3.23.0
*
* @param {Phaser.Cameras.Scene2D.Camera} camera - The camera this effect is acting upon.
*/
var RotateTo = new Class({
initialize:
function RotateTo (camera)
{
/**
* The Camera this effect belongs to.
*
* @name Phaser.Cameras.Scene2D.Effects.RotateTo#camera
* @type {Phaser.Cameras.Scene2D.Camera}
* @readonly
* @since 3.23.0
*/
this.camera = camera;
/**
* Is this effect actively running?
*
* @name Phaser.Cameras.Scene2D.Effects.RotateTo#isRunning
* @type {boolean}
* @readonly
* @default false
* @since 3.23.0
*/
this.isRunning = false;
/**
* The duration of the effect, in milliseconds.
*
* @name Phaser.Cameras.Scene2D.Effects.RotateTo#duration
* @type {number}
* @readonly
* @default 0
* @since 3.23.0
*/
this.duration = 0;
/**
* The starting angle to rotate the camera from, in radians.
*
* @name Phaser.Cameras.Scene2D.Effects.RotateTo#source
* @type {number}
* @since 3.23.0
*/
this.source = 0;
/**
* The current camera angle during the rotation, in radians.
*
* @name Phaser.Cameras.Scene2D.Effects.RotateTo#current
* @type {number}
* @since 3.23.0
*/
this.current = 0;
/**
* The destination angle to rotate the camera to, in radians.
*
* @name Phaser.Cameras.Scene2D.Effects.RotateTo#destination
* @type {number}
* @since 3.23.0
*/
this.destination = 0;
/**
* The ease function to use during the rotation.
*
* @name Phaser.Cameras.Scene2D.Effects.RotateTo#ease
* @type {function}
* @since 3.23.0
*/
this.ease;
/**
* If this effect is running this holds the current progress, a value between 0 (start) and 1 (end).
*
* @name Phaser.Cameras.Scene2D.Effects.RotateTo#progress
* @type {number}
* @since 3.23.0
*/
this.progress = 0;
/**
* The elapsed duration of the effect, in milliseconds.
*
* @name Phaser.Cameras.Scene2D.Effects.RotateTo#_elapsed
* @type {number}
* @private
* @since 3.23.0
*/
this._elapsed = 0;
/**
* This callback is invoked every frame for the duration of the effect.
*
* @name Phaser.Cameras.Scene2D.Effects.RotateTo#_onUpdate
* @type {?CameraRotateCallback}
* @private
* @default null
* @since 3.23.0
*/
this._onUpdate;
/**
* Context (`this` value) for the update callback.
*
* @name Phaser.Cameras.Scene2D.Effects.RotateTo#_onUpdateScope
* @type {any}
* @private
* @since 3.23.0
*/
this._onUpdateScope;
/**
* Whether the rotation is progressing in a clockwise (`true`) or counter-clockwise (`false`) direction.
*
* @name Phaser.Cameras.Scene2D.Effects.RotateTo#clockwise
* @type {boolean}
* @since 3.23.0
*/
this.clockwise = true;
/**
* Whether the effect should rotate via the shortest angular path to the destination angle.
*
* @name Phaser.Cameras.Scene2D.Effects.RotateTo#shortestPath
* @type {boolean}
* @since 3.23.0
*/
this.shortestPath = false;
},
/**
* Rotate the Camera to the given angle over the duration and with the ease specified.
*
* @method Phaser.Cameras.Scene2D.Effects.RotateTo#start
* @fires Phaser.Cameras.Scene2D.Events#ROTATE_START
* @fires Phaser.Cameras.Scene2D.Events#ROTATE_COMPLETE
* @since 3.23.0
*
* @param {number} angle - The destination angle in radians to rotate the Camera view to.
* @param {boolean} [shortestPath=false] - If true, take the shortest distance to the destination. This adjusts the destination angle to be within one half turn of the start angle.
* @param {number} [duration=1000] - The duration of the effect in milliseconds.
* @param {(string|function)} [ease='Linear'] - The ease to use. Can be any of the Phaser Easing constants or a custom function.
* @param {boolean} [force=false] - Force the rotation effect to start immediately, even if already running.
* @param {Phaser.Types.Cameras.Scene2D.CameraRotateCallback} [callback] - This callback will be invoked every frame for the duration of the effect.
* It is sent three arguments: A reference to the camera, a progress amount between 0 and 1 indicating how complete the effect is,
* and the current camera rotation.
* @param {any} [context] - The context in which the callback is invoked. Defaults to the Scene to which the Camera belongs.
*
* @return {Phaser.Cameras.Scene2D.Camera} The Camera on which the effect was started.
*/
start: function (angle, shortestPath, duration, ease, force, callback, context)
{
if (duration === undefined) { duration = 1000; }
if (ease === undefined) { ease = EaseMap.Linear; }
if (force === undefined) { force = false; }
if (callback === undefined) { callback = null; }
if (context === undefined) { context = this.camera.scene; }
if (shortestPath === undefined) { shortestPath = false; }
var cam = this.camera;
if (!force && this.isRunning)
{
return cam;
}
this.shortestPath = shortestPath;
this.isRunning = true;
this.duration = duration;
this.progress = 0;
// Starting from
this.source = cam.rotation;
// Destination
this.destination = angle;
// Using this ease
if (typeof ease === 'string' && EaseMap.hasOwnProperty(ease))
{
this.ease = EaseMap[ease];
}
else if (typeof ease === 'function')
{
this.ease = ease;
}
this._elapsed = 0;
this._onUpdate = callback;
this._onUpdateScope = context;
if (this.shortestPath)
{
var distance = WrapAngle(this.destination - this.source);
this.destination = this.source + distance;
this.clockwise = distance >= 0;
}
else
{
this.clockwise = this.destination >= this.source;
}
this.camera.emit(Events.ROTATE_START, this.camera, this, duration, this.destination);
return cam;
},
/**
* The main update loop for this effect. Called automatically by the Camera.
*
* @method Phaser.Cameras.Scene2D.Effects.RotateTo#update
* @since 3.23.0
*
* @param {number} time - The current timestamp as generated by the Request Animation Frame or SetTimeout.
* @param {number} delta - The delta time, in ms, elapsed since the last frame.
*/
update: function (time, delta)
{
if (!this.isRunning)
{
return;
}
this._elapsed += delta;
var progress = Clamp(this._elapsed / this.duration, 0, 1);
this.progress = progress;
var cam = this.camera;
if (this._elapsed < this.duration)
{
var v = this.ease(progress);
var r = this.source + v * (this.destination - this.source);
cam.rotation = r;
this.current = r;
if (this._onUpdate)
{
this._onUpdate.call(this._onUpdateScope, cam, progress, r);
}
}
else
{
cam.rotation = this.destination;
this.current = this.destination;
if (this._onUpdate)
{
this._onUpdate.call(this._onUpdateScope, cam, progress, this.destination);
}
this.effectComplete();
}
},
/**
* Called internally when the effect completes.
*
* @method Phaser.Cameras.Scene2D.Effects.RotateTo#effectComplete
* @since 3.23.0
*/
effectComplete: function ()
{
this._onUpdate = null;
this._onUpdateScope = null;
this.isRunning = false;
this.camera.emit(Events.ROTATE_COMPLETE, this.camera, this);
},
/**
* Resets this camera effect.
* If it was previously running, it stops instantly without calling its onComplete callback or emitting an event.
*
* @method Phaser.Cameras.Scene2D.Effects.RotateTo#reset
* @since 3.23.0
*/
reset: function ()
{
this.isRunning = false;
this._onUpdate = null;
this._onUpdateScope = null;
},
/**
* Destroys this effect, releasing it from the Camera.
*
* @method Phaser.Cameras.Scene2D.Effects.RotateTo#destroy
* @since 3.23.0
*/
destroy: function ()
{
this.reset();
this.camera = null;
this.source = null;
this.destination = null;
}
});
module.exports = RotateTo;