phaser/src/renderer/webgl/wrappers/WebGLAttribLocationWrapper.js

A fast, free and fun HTML5 Game Framework for Desktop and Mobile web browsers from the team at Phaser Studio Inc.

/**
 * @author       Benjamin D. Richards <benjamindrichards@gmail.com>
 * @copyright    2013-2025 Phaser Studio Inc.
 * @license      {@link https://opensource.org/licenses/MIT|MIT License}
 */

var Class = require('../../../utils/Class');

/**
 * @classdesc
 * Wrapper for a WebGL attribute location, containing all the information that was used to create it.
 *
 * A WebGLAttribLocation should never be exposed outside the WebGLRenderer,
 * so the WebGLRenderer can handle context loss and other events without other systems having to be aware of it.
 * Always use WebGLAttribLocationWrapper instead.
 *
 * @class WebGLAttribLocationWrapper
 * @memberof Phaser.Renderer.WebGL.Wrappers
 * @constructor
 * @since 3.80.0
 *
 * @param {WebGLRenderingContext} gl - The WebGLRenderingContext to create the WebGLAttribLocation for.
 * @param {Phaser.Renderer.WebGL.Wrappers.WebGLProgramWrapper} program - The WebGLProgram that this location refers to. This must be created first.
 * @param {string} name - The name of this location, as defined in the shader source code.
 */
var WebGLAttribLocationWrapper = new Class({

    initialize:

    function WebGLAttribLocationWrapper (gl, program, name)
    {
        /**
         * The WebGLAttribLocation being wrapped by this class.
         *
         * This property could change at any time.
         * Therefore, you should never store a reference to this value.
         * It should only be passed directly to the WebGL API for drawing.
         *
         * @name Phaser.Renderer.WebGL.Wrappers.WebGLAttribLocationWrapper#webGLAttribLocation
         * @type {GLint}
         * @default -1
         * @since 3.80.0
         */
        this.webGLAttribLocation = -1;

        /**
         * The WebGLRenderingContext that owns this location.
         *
         * @name Phaser.Renderer.WebGL.Wrappers.WebGLAttribLocationWrapper#gl
         * @type {WebGLRenderingContext}
         * @since 3.80.0
         */
        this.gl = gl;

        /**
         * The WebGLProgram that this location refers to.
         *
         * @name Phaser.Renderer.WebGL.Wrappers.WebGLAttribLocationWrapper#program
         * @type {Phaser.Renderer.WebGL.Wrappers.WebGLProgramWrapper}
         * @since 3.80.0
         */
        this.program = program;

        /**
         * The name of this location, as defined in the shader source code.
         *
         * @name Phaser.Renderer.WebGL.Wrappers.WebGLAttribLocationWrapper#name
         * @type {string}
         * @since 3.80.0
         */
        this.name = name;

        this.createResource();
    },

    /**
     * Creates the WebGLAttribLocation.
     *
     * @method Phaser.Renderer.WebGL.Wrappers.WebGLAttribLocationWrapper#createResource
     * @since 3.80.0
     */
    createResource: function ()
    {
        if (this.program.webGLProgram === null)
        {
            this.webGLAttribLocation = -1;
            return;
        }

        var gl = this.gl;

        if (gl.isContextLost())
        {
            // GL state can't be updated right now.
            // `createResource` will run when the context is restored.
            return;
        }

        this.webGLAttribLocation = gl.getAttribLocation(this.program.webGLProgram, this.name);
    },

    /**
     * Destroys this WebGLAttribLocationWrapper.
     *
     * @method Phaser.Renderer.WebGL.Wrappers.WebGLAttribLocationWrapper#destroy
     * @since 3.80.0
     */
    destroy: function ()
    {
        this.gl = null;
        this.program = null;
        this.name = null;
        this.webGLAttribLocation = -1;
    }
});

module.exports = WebGLAttribLocationWrapper;