Generate TMS pyramid

pyramid.js

import * as path from "https://deno.land/std/path/mod.ts";

const encoder = new TextEncoder();

const dot = encoder.encode(".");
const dash = encoder.encode("-");

for (let zz = 18; zz >= 0; zz--) {
  const base = `/home/martin/ofmozaika/${zz + 1}`;

  const zoom = zz;

  const coords = new Set();

  for await (const file of Deno.readDir(base)) {
    const name = path.join(base, file.name);

    console.log(name);

    const x = Number(file.name);

    for await (const file1 of Deno.readDir(name)) {
      const name1 = path.join(name, file1.name);

      const y = Number(file1.name.slice(0, -4));

      //     if (y > 300000) {
      //       await Deno.rename(name1, `${name}/${524287 - y}.jpg`);
      //     } else {
      //       console.log("???", y);
      //     }

      coords.add(`${Math.floor(x / 2)}/${Math.floor(y / 2)}`);
    }
  }

  console.log("Let's go...");

  let promises = [];

  for (const coord of coords) {
    const [x, y] = coord.split("/");

    const xx = x * 2;
    const yy = y * 2;

    const parts = [
      `${base}/${xx}/${yy}.jpg`,
      `${base}/${xx}/${yy + 1}.jpg`,
      `${base}/${xx + 1}/${yy}.jpg`,
      `${base}/${xx + 1}/${yy + 1}.jpg`,
    ];

    try {
      await Deno.stat(`${zoom}/${x}/${y}.jpg`);

      Deno.stdout.write(dash);

      continue;
    } catch {
      // ignore
    }

    const fn = async () => {
      Deno.stdout.write(dot);

      await Deno.mkdir(`${zoom}/${x}`, { recursive: true });

      for (let i = 0; i < 4; i++) {
        try {
          await Deno.stat(parts[i]);
        } catch {
          parts[i] = "white.png";
        }
      }

      const proc = Deno.run({
        cmd: [
          "convert",
          "(",
          parts[0],
          parts[2],
          "+append",
          ")",
          "(",
          parts[1],
          parts[3],
          "+append",
          ")",
          "-append",
          "-resize",
          "256x256",
          `${zoom}/${x}/${y}.jpg`,
        ],
        stdout: "null",
        stderr: "null",
        stdin: "null",
      });

      await proc.status();

      proc.close();
    };

    const p = fn();

    p.then(() => {
      p.done = true;
    });

    promises.push(p);

    if (promises.length > 24) {
      await Promise.race(promises);
      promises = promises.filter((p) => !p.done);
    }
  }
  
  console.log("FLUSH");

  await Promise.all(promises);
}

console.log("FIN");