@loaders.gl/textures/dist/lib/texture-api/load-image.js

Framework-independent loaders for compressed and super compressed (basis) textures

// loaders.gl
// SPDX-License-Identifier: MIT
// Copyright (c) vis.gl contributors
import { assert } from '@loaders.gl/loader-utils';
import { ImageLoader, getImageSize } from '@loaders.gl/images';
import { generateUrl } from "./generate-url.js";
import { deepLoad, shallowLoad } from "./deep-load.js";
export async function loadImageTexture(getUrl, options = {}) {
    const imageUrls = await getImageUrls(getUrl, options);
    return await deepLoad(imageUrls, ImageLoader.parse, options);
}
export async function getImageUrls(getUrl, options, urlOptions = {}) {
    const mipLevels = (options && options.image && options.image.mipLevels) || 0;
    return mipLevels !== 0
        ? await getMipmappedImageUrls(getUrl, mipLevels, options, urlOptions)
        : generateUrl(getUrl, options, urlOptions);
}
async function getMipmappedImageUrls(getUrl, mipLevels, options, urlOptions) {
    const urls = [];
    // If no mip levels supplied, we need to load the level 0 image and calculate based on size
    if (mipLevels === 'auto') {
        const url = generateUrl(getUrl, options, { ...urlOptions, lod: 0 });
        const image = await shallowLoad(url, ImageLoader.parse, options);
        const { width, height } = getImageSize(image);
        mipLevels = getMipLevels({ width, height });
        // TODO - push image and make `deepLoad` pass through non-url values, avoid loading twice?
        urls.push(url);
    }
    // We now know how many mipLevels we need, remaining image urls can now be constructed
    assert(mipLevels > 0);
    for (let mipLevel = urls.length; mipLevel < mipLevels; ++mipLevel) {
        const url = generateUrl(getUrl, options, { ...urlOptions, lod: mipLevel });
        urls.push(url);
    }
    return urls;
}
// Calculates number of mipmaps based on texture size (log2)
export function getMipLevels(size) {
    return 1 + Math.floor(Math.log2(Math.max(size.width, size.height)));
}