114 lines
2.7 KiB
TypeScript
114 lines
2.7 KiB
TypeScript
/**
|
|
* Identicon generator
|
|
* https://en.wikipedia.org/wiki/Identicon
|
|
*/
|
|
|
|
import type { WriteStream } from "node:fs";
|
|
import * as p from "pureimage";
|
|
import gen from "random-seed";
|
|
|
|
const size = 128; // px
|
|
const n = 5; // resolution
|
|
const margin = size / 4;
|
|
const colors = [
|
|
["#eb6f92", "#b4637a"],
|
|
["#f6c177", "#ea9d34"],
|
|
["#ebbcba", "#d7827e"],
|
|
["#9ccfd8", "#56949f"],
|
|
["#c4a7e7", "#907aa9"],
|
|
["#eb6f92", "#f6c177"],
|
|
["#eb6f92", "#ebbcba"],
|
|
["#eb6f92", "#31748f"],
|
|
["#eb6f92", "#9ccfd8"],
|
|
["#eb6f92", "#c4a7e7"],
|
|
["#f6c177", "#eb6f92"],
|
|
["#f6c177", "#ebbcba"],
|
|
["#f6c177", "#31748f"],
|
|
["#f6c177", "#9ccfd8"],
|
|
["#f6c177", "#c4a7e7"],
|
|
["#ebbcba", "#eb6f92"],
|
|
["#ebbcba", "#f6c177"],
|
|
["#ebbcba", "#31748f"],
|
|
["#ebbcba", "#9ccfd8"],
|
|
["#ebbcba", "#c4a7e7"],
|
|
["#31748f", "#eb6f92"],
|
|
["#31748f", "#f6c177"],
|
|
["#31748f", "#ebbcba"],
|
|
["#31748f", "#9ccfd8"],
|
|
["#31748f", "#c4a7e7"],
|
|
["#9ccfd8", "#eb6f92"],
|
|
["#9ccfd8", "#f6c177"],
|
|
["#9ccfd8", "#ebbcba"],
|
|
["#9ccfd8", "#31748f"],
|
|
["#9ccfd8", "#c4a7e7"],
|
|
["#c4a7e7", "#eb6f92"],
|
|
["#c4a7e7", "#f6c177"],
|
|
["#c4a7e7", "#ebbcba"],
|
|
["#c4a7e7", "#31748f"],
|
|
["#c4a7e7", "#9ccfd8"],
|
|
];
|
|
|
|
const actualSize = size - margin * 2;
|
|
const cellSize = actualSize / n;
|
|
const sideN = Math.floor(n / 2);
|
|
|
|
/**
|
|
* Generate buffer of an identicon by seed
|
|
*/
|
|
export function genIdenticon(seed: string, stream: WriteStream): Promise<void> {
|
|
const rand = gen.create(seed);
|
|
const canvas = p.make(size, size, undefined);
|
|
const ctx = canvas.getContext("2d");
|
|
|
|
const bgColors = colors[rand(colors.length)];
|
|
|
|
const bg = ctx.createLinearGradient(0, 0, size, size);
|
|
bg.addColorStop(0, bgColors[0]);
|
|
bg.addColorStop(1, bgColors[1]);
|
|
|
|
ctx.fillStyle = bg;
|
|
ctx.beginPath();
|
|
ctx.fillRect(0, 0, size, size);
|
|
|
|
ctx.fillStyle = "#ffffff";
|
|
|
|
// side bitmap (filled by false)
|
|
const side: boolean[][] = new Array(sideN);
|
|
for (let i = 0; i < side.length; i++) {
|
|
side[i] = new Array(n).fill(false);
|
|
}
|
|
|
|
// 1*n (filled by false)
|
|
const center: boolean[] = new Array(n).fill(false);
|
|
|
|
for (let x = 0; x < side.length; x++) {
|
|
for (let y = 0; y < side[x].length; y++) {
|
|
side[x][y] = rand(3) === 0;
|
|
}
|
|
}
|
|
|
|
for (let i = 0; i < center.length; i++) {
|
|
center[i] = rand(3) === 0;
|
|
}
|
|
|
|
// Draw
|
|
for (let x = 0; x < n; x++) {
|
|
for (let y = 0; y < n; y++) {
|
|
const isXCenter = x === (n - 1) / 2;
|
|
if (isXCenter && !center[y]) continue;
|
|
|
|
const isLeftSide = x < (n - 1) / 2;
|
|
if (isLeftSide && !side[x][y]) continue;
|
|
|
|
const isRightSide = x > (n - 1) / 2;
|
|
if (isRightSide && !side[sideN - (x - sideN)][y]) continue;
|
|
|
|
const actualX = margin + cellSize * x;
|
|
const actualY = margin + cellSize * y;
|
|
ctx.beginPath();
|
|
ctx.fillRect(actualX, actualY, cellSize, cellSize);
|
|
}
|
|
}
|
|
|
|
return p.encodePNGToStream(canvas, stream);
|
|
}
|