Source: packages/core/src/textures/resources/ArrayResource.js

import { AbstractMultiResource } from './AbstractMultiResource';
import { TARGETS } from '@pixi/constants';
/**
 * A resource that contains a number of sources.
 *
 * @class
 * @extends PIXI.resources.Resource
 * @memberof PIXI.resources
 * @param {number|Array<*>} source - Number of items in array or the collection
 *        of image URLs to use. Can also be resources, image elements, canvas, etc.
 * @param {object} [options] - Options to apply to {@link PIXI.resources.autoDetectResource}
 * @param {number} [options.width] - Width of the resource
 * @param {number} [options.height] - Height of the resource
 */
export class ArrayResource extends AbstractMultiResource {
    constructor(source, options) {
        const { width, height } = options || {};
        let urls;
        let length;
        if (Array.isArray(source)) {
            urls = source;
            length = source.length;
        }
        else {
            length = source;
        }
        super(length, { width, height });
        if (urls) {
            this.initFromArray(urls, options);
        }
    }
    /**
     * Set a baseTexture by ID,
     * ArrayResource just takes resource from it, nothing more
     *
     * @param {PIXI.BaseTexture} baseTexture
     * @param {number} index - Zero-based index of resource to set
     * @return {PIXI.resources.ArrayResource} Instance for chaining
     */
    addBaseTextureAt(baseTexture, index) {
        if (baseTexture.resource) {
            this.addResourceAt(baseTexture.resource, index);
        }
        else {
            throw new Error('ArrayResource does not support RenderTexture');
        }
        return this;
    }
    /**
     * Add binding
     * @member {PIXI.BaseTexture}
     * @override
     */
    bind(baseTexture) {
        super.bind(baseTexture);
        baseTexture.target = TARGETS.TEXTURE_2D_ARRAY;
    }
    /**
     * Upload the resources to the GPU.
     * @param {PIXI.Renderer} renderer
     * @param {PIXI.BaseTexture} texture
     * @param {PIXI.GLTexture} glTexture
     * @returns {boolean} whether texture was uploaded
     */
    upload(renderer, texture, glTexture) {
        const { length, itemDirtyIds, items } = this;
        const { gl } = renderer;
        if (glTexture.dirtyId < 0) {
            gl.texImage3D(gl.TEXTURE_2D_ARRAY, 0, texture.format, this._width, this._height, length, 0, texture.format, texture.type, null);
        }
        for (let i = 0; i < length; i++) {
            const item = items[i];
            if (itemDirtyIds[i] < item.dirtyId) {
                itemDirtyIds[i] = item.dirtyId;
                if (item.valid) {
                    gl.texSubImage3D(gl.TEXTURE_2D_ARRAY, 0, 0, // xoffset
                    0, // yoffset
                    i, // zoffset
                    item.resource.width, item.resource.height, 1, texture.format, texture.type, item.resource.source);
                }
            }
        }
        return true;
    }
}