phaser/v3/merge/gameobjects/components/FixedToCamera.js
2016-11-23 00:17:46 +00:00

88 lines
2.8 KiB
JavaScript

/**
* @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 FixedToCamera component enables a Game Object to be rendered relative to the game camera coordinates, regardless
* of where in the world the camera is. This is used for things like sticking game UI to the camera that scrolls as it moves around the world.
*
* @class
*/
Phaser.Component.FixedToCamera = function () {};
/**
* The FixedToCamera component postUpdate handler.
* Called automatically by the Game Object.
*
* @method
*/
Phaser.Component.FixedToCamera.postUpdate = function () {
if (this.fixedToCamera)
{
this.position.x = (this.game.camera.view.x + this.cameraOffset.x) / this.game.camera.scale.x;
this.position.y = (this.game.camera.view.y + this.cameraOffset.y) / this.game.camera.scale.y;
}
};
Phaser.Component.FixedToCamera.prototype = {
/**
* @property {boolean} _fixedToCamera
* @private
*/
_fixedToCamera: false,
/**
* A Game Object that is "fixed" to the camera uses its x/y coordinates as offsets from the top left of the camera during rendering.
*
* The values are adjusted at the rendering stage, overriding the Game Objects actual world position.
*
* The end result is that the Game Object will appear to be 'fixed' to the camera, regardless of where in the game world
* the camera is viewing. This is useful if for example this Game Object is a UI item that you wish to be visible at all times
* regardless where in the world the camera is.
*
* The offsets are stored in the `cameraOffset` property.
*
* Note that the `cameraOffset` values are in addition to any parent of this Game Object on the display list.
*
* Be careful not to set `fixedToCamera` on Game Objects which are in Groups that already have `fixedToCamera` enabled on them.
*
* @property {boolean} fixedToCamera
*/
fixedToCamera: {
get: function () {
return this._fixedToCamera;
},
set: function (value) {
if (value)
{
this._fixedToCamera = true;
this.cameraOffset.set(this.x, this.y);
}
else
{
this._fixedToCamera = false;
}
}
},
/**
* The x/y coordinate offset applied to the top-left of the camera that this Game Object will be drawn at if `fixedToCamera` is true.
*
* The values are relative to the top-left of the camera view and in addition to any parent of the Game Object on the display list.
* @property {Phaser.Point} cameraOffset
*/
cameraOffset: new Phaser.Point()
};