@here/harp-mapview/lib/TextureLoader.js

Functionality needed to render a map.

"use strict";
/*
 * Copyright (C) 2020 HERE Europe B.V.
 * Licensed under Apache 2.0, see full license in LICENSE
 * SPDX-License-Identifier: Apache-2.0
 */
Object.defineProperty(exports, "__esModule", { value: true });
exports.TextureLoader = void 0;
const THREE = require("three");
/**
 * A texture loader that supports request headers(e.g. for Authorization)
 */
class TextureLoader {
    constructor() {
        this.m_textureLoader = new THREE.TextureLoader();
    }
    /**
     * Load an image from url and create a texture
     * @param url - URL to the image
     * @param requestHeaders - Optional request headers to load image(e.g. Authorization)
     * @param abortSignal - Optional AbortSignal to cancel the load.
     * @param crossOrigin - Enable/disable CORS
     */
    async load(url, requestHeaders, abortSignal, crossOrigin = true) {
        // Use THREE.js texture loader directly if no request header is set
        if (requestHeaders === undefined) {
            return await this.loadWithThreeLoader(url);
        }
        // Load image with fetch API if request header is set
        const response = await fetch(url, {
            headers: requestHeaders,
            signal: abortSignal,
            mode: crossOrigin ? "cors" : "no-cors"
        });
        const blob = await response.blob();
        // Load image from blob using THREE.js loader
        const texture = await this.loadWithThreeLoader(URL.createObjectURL(blob));
        // Set correct image format from original URL or blob mime type
        // (object URL does not contain file format)
        const isJPEG = blob.type === "image/jpeg/" ||
            url.search(/\.jpe?g($|\?)/i) > 0 ||
            url.search(/^data\:image\/jpeg/) === 0;
        texture.format = isJPEG ? THREE.RGBFormat : THREE.RGBAFormat;
        return texture;
    }
    loadWithThreeLoader(url) {
        return new Promise((resolve, reject) => {
            this.m_textureLoader.setCrossOrigin("");
            this.m_textureLoader.load(url, texture => resolve(texture), undefined, () => reject(new Error("failed to load texture")));
        });
    }
}
exports.TextureLoader = TextureLoader;
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