Minetest-WorldEditAdditions/.docs/lib/HTMLPicture.js

155 lines
5.7 KiB
JavaScript
Raw Normal View History

"use strict";
const os = require(`os`);
const fs = require("fs");
const path = require("path");
const pretty_ms = require("pretty-ms");
const debug = require("debug")("image");
const imagickal = require("imagickal");
const htmlentities = require("html-entities");
const a = require("./Ansi.js");
function calculate_size(width, height, size_spec) {
if(size_spec.indexOf("%") > -1) {
// It's a percentage
const multiplier = parseInt(size_spec.replace(/%/, ""), 10) / 100;
return {
width: Math.ceil(width * multiplier),
height: Math.ceil(height * multiplier)
};
}
else {
// It's an absolute image width
const new_width = parseInt(size_spec, 10);
return {
width: new_width,
height: Math.ceil(new_width/width * height)
};
}
}
// Main task list - we make sure it completes before exiting.
var queue = null;
async function make_queue() {
// 1: Setup task queue
const PQueue = (await import("p-queue")).default;
let concurrency = os.cpus().length;
if(process.env["MAX_CONCURRENT"])
concurrency = parseInt(process.env["MAX_CONCURRENT"], 10);
debug(`Image conversion queue concurrency: `, concurrency);
queue = new PQueue({ concurrency });
queue.on("idle", () => console.log(`IMAGE ${a.fcyan}all conversions complete${a.reset}`));
process.on("exit", async () => {
debug(`Waiting for image conversions to finish...`);
await queue.onEmpty();
debug(`All image conversions complete.`);
});
}
async function srcset(source_image, target_dir, urlpath, format = "__AUTO__", sizes = [ "25%", "50%", "100%" ], quality = 95, strip = true) {
if(queue === null) await make_queue();
const source_parsed = path.parse(source_image);
// ext contains the dot . already
const target_format = format == "__AUTO__" ? source_parsed.ext.replace(/\./g, "") : format;
const source_size = await imagickal.dimensions(source_image);
debug(`SOURCE_SIZE`, source_size, `TARGET_FORMAT`, target_format);
let setitems = await Promise.all(sizes.map(async (size) => {
let target_filename = `${source_parsed.name}_${size}.${target_format}`
.replace(/%/, "pcent");
let target_current = path.join(
target_dir,
target_filename
);
queue.add(async () => {
const start = new Date();
await imagickal.transform(source_image, target_current, {
resize: { width: size },
quality,
strip
});
2022-07-06 02:41:27 +02:00
console.log(`${a.fmagenta}${a.hicol}IMAGE${a.reset}\t${a.fcyan}${queue.size}/${queue.pending} tasks${a.reset}\t${a.fyellow}${pretty_ms(new Date() - start)}${a.reset}\t${a.fgreen}${target_current}${a.reset}`);
});
// const size_target = await imagickal.dimensions(target_current);
const predict = calculate_size(source_size.width, source_size.height, size);
// debug(`size spec:`, size, `size predicted: ${predict.width}x${predict.height} actual: ${size_target.width}x${size_target.height}`);
return `${path.resolve(urlpath, target_filename)} ${predict.width}w`;
}));
return setitems.join(", ");
}
/**
* Generates a string of HTML for a <picture> element, converting images to the specified formats in the process.
* @param {string} source_image The filepath to the source image.
* @param {string} alt The alt (alternative) text. Automatically run though htmlentities.
* @param {string} target_dir The target directory to save converted images to.
* @param {string} urlpath The path to the aforementionoed target directory as a URL. Image paths in the HTML will be prefixed with this value.
* @param {string} [formats="__AUTO__"] A list of formats to convert the source image to. Defaults to automatically determining the most optimal formats based on the input format. [must be lowercase]
* @param {Array} [sizes=["25%","50%", "100%" ]] The sizes, as imagemagick size specs, to convert the source image to.
* @param {Number} [quality=95] The quality value to use when converting images.
* @param {Boolean} [strip=true] Whether to strip all metadata from images when converting them [saves some space]
* @return {Promise<string>} A Promise that returns a generated string of HTML.
*/
async function picture(source_image, alt, target_dir, urlpath, formats = "__AUTO__", sizes = [ "25%", "50%", "100%" ], quality = 95, strip = true) {
const source_parsed = path.parse(source_image);
const source_format = source_parsed.ext.toLowerCase().replace(".", "");
if(formats == "__AUTO__") {
switch(source_format) {
case "png":
case "gif": // * shudder *
case "bmp":
formats = [ "png" ];
break;
default:
// jxl = JPEG XL <https://jpegxl.info/> - not currently supported by the old version of imagemagick shipped via apt :-/
// Imagemagick v7+ does support it, but isn't shipped yet :-(
formats = [ "jpeg", "webp", "avif", /*"jxl"*/ ];
break;
}
}
const target_original = path.join(target_dir, source_parsed.base);
await fs.promises.copyFile(source_image, target_original);
const sources = await Promise.all(formats.map(async (format) => {
debug(`${format} ${source_image}`);
return {
mime: `image/${format}`,
srcset: await srcset(
source_image,
target_dir, urlpath,
format, sizes,
quality, strip
)
};
}));
let result = `<picture>\n\t`;
result += sources.map(source => `<source srcset="${source.srcset}" type="${source.mime}" />`).join(`\n\t`);
result += `\n\t<img loading="lazy" decoding="async" src="${urlpath}/${source_parsed.base}" alt="${htmlentities.encode(alt)}" />\n`;
result += `</picture>\n`
return result;
}
var picture_memoize = null;
async function setup_memoize() {
const pMemoize = (await import("p-memoize")).default;
picture_memoize = pMemoize(picture);
}
module.exports = async function(...args) {
if(picture_memoize === null) await setup_memoize();
return await picture_memoize(...args);
};