generated from polymech/site-template
59 lines
1.3 KiB
JavaScript
59 lines
1.3 KiB
JavaScript
// @ts-check
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import util from "node:util";
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import potrace from "potrace";
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import getSrcset from "./getSrcset.js";
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import { sharp } from "../../utils/runtimeChecks.js";
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export default async function getFallbackImage(
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src,
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placeholder,
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image,
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format,
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formatOptions,
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rest
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) {
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const base = null;
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switch (placeholder) {
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case "blurred": {
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const dataUri = await getSrcset(src, base, [20], format, {
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inline: true,
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...rest,
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...formatOptions[format],
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});
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return dataUri;
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}
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case "tracedSVG": {
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const { function: fn, options } = formatOptions.tracedSVG;
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const traceSVG = util.promisify(potrace[fn]);
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const imageBuffer = sharp
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? await image.toBuffer()
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: Buffer.from(
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(await image.encode(`image/${format === "jpg" ? "jpeg" : format}`))
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.data
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);
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const tracedSVG = await traceSVG(imageBuffer, options);
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return `data:image/svg+xml;utf8,${tracedSVG}`;
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}
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case "dominantColor": {
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if (sharp) {
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var { r, g, b } = (await image.stats()).dominant;
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} else {
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[r, g, b] = image.color;
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}
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const svg = `<svg xmlns="http://www.w3.org/2000/svg" style="background: rgb(${r},${g},${b})"></svg>`;
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return `data:image/svg+xml;utf8,${svg}`;
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}
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default:
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return null;
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}
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}
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