Glow.js

/**
 * @author       Richard Davey <rich@photonstorm.com>
 * @copyright    2013-2023 Photon Storm Ltd.
 * @license      {@link https://opensource.org/licenses/MIT|MIT License}
 */

var Class = require('../utils/Class');
var Controller = require('./Controller');
var FX_CONST = require('./const');

/**
 * @classdesc
 * The Glow FX Controller.
 *
 * This FX controller manages the glow effect for a Game Object.
 *
 * The glow effect is a visual technique that creates a soft, luminous halo around game objects,
 * characters, or UI elements. This effect is used to emphasize importance, enhance visual appeal,
 * or convey a sense of energy, magic, or otherworldly presence. The effect can also be set on
 * the inside of the Game Object. The color and strength of the glow can be modified.
 *
 * A Glow effect is added to a Game Object via the FX component:
 *
 * ```js
 * const sprite = this.add.sprite();
 *
 * sprite.preFX.addGlow();
 * sprite.postFX.addGlow();
 * ```
 *
 * @class Glow
 * @extends Phaser.FX.Controller
 * @memberof Phaser.FX
 * @constructor
 * @since 3.60.0
 *
 * @param {Phaser.GameObjects.GameObject} gameObject - A reference to the Game Object that has this fx.
 * @param {number} [color=0xffffff] - The color of the glow effect as a number value.
 * @param {number} [outerStrength=4] - The strength of the glow outward from the edge of the Sprite.
 * @param {number} [innerStrength=0] - The strength of the glow inward from the edge of the Sprite.
 * @param {boolean} [knockout=false] - If `true` only the glow is drawn, not the texture itself.
 */
var Glow = new Class({

    Extends: Controller,

    initialize:

    function Glow (gameObject, color, outerStrength, innerStrength, knockout)
    {
        if (outerStrength === undefined) { outerStrength = 4; }
        if (innerStrength === undefined) { innerStrength = 0; }
        if (knockout === undefined) { knockout = false; }

        Controller.call(this, FX_CONST.GLOW, gameObject);

        /**
         * The strength of the glow outward from the edge of the Sprite.
         *
         * @name Phaser.FX.Glow#outerStrength
         * @type {number}
         * @since 3.60.0
         */
        this.outerStrength = outerStrength;

        /**
         * The strength of the glow inward from the edge of the Sprite.
         *
         * @name Phaser.FX.Glow#innerStrength
         * @type {number}
         * @since 3.60.0
         */
        this.innerStrength = innerStrength;

        /**
         * If `true` only the glow is drawn, not the texture itself.
         *
         * @name Phaser.FX.Glow#knockout
         * @type {number}
         * @since 3.60.0
         */
        this.knockout = knockout;

        /**
         * A 4 element array of gl color values.
         *
         * @name Phaser.FX.Glow#glcolor
         * @type {number[]}
         * @since 3.60.0
         */
        this.glcolor = [ 1, 1, 1, 1 ];

        if (color !== undefined)
        {
            this.color = color;
        }
    },

    /**
     * The color of the glow as a number value.
     *
     * @name Phaser.FX.Glow#color
     * @type {number}
     * @since 3.60.0
     */
    color: {

        get: function ()
        {
            var color = this.glcolor;

            return (((color[0] * 255) << 16) + ((color[1] * 255) << 8) + (color[2] * 255 | 0));
        },

        set: function (value)
        {
            var color = this.glcolor;

            color[0] = ((value >> 16) & 0xFF) / 255;
            color[1] = ((value >> 8) & 0xFF) / 255;
            color[2] = (value & 0xFF) / 255;
        }

    }

});

module.exports = Glow;