Sharkey/src/misc/gen-avatar.ts
2021-04-02 10:00:05 +09:00

90 lines
1.9 KiB
TypeScript

/**
* Random avatar generator
*/
const p = require('pureimage');
import * as gen from 'random-seed';
import { WriteStream } from 'fs';
const size = 256; // px
const n = 5; // resolution
const margin = (size / n);
const colors = [
'#e57373',
'#F06292',
'#BA68C8',
'#9575CD',
'#7986CB',
'#64B5F6',
'#4FC3F7',
'#4DD0E1',
'#4DB6AC',
'#81C784',
'#8BC34A',
'#AFB42B',
'#F57F17',
'#FF5722',
'#795548',
'#455A64',
];
const bg = '#e9e9e9';
const actualSize = size - (margin * 2);
const cellSize = actualSize / n;
const sideN = Math.floor(n / 2);
/**
* Generate buffer of random avatar by seed
*/
export function genAvatar(seed: string, stream: WriteStream): Promise<void> {
const rand = gen.create(seed);
const canvas = p.make(size, size);
const ctx = canvas.getContext('2d');
ctx.fillStyle = bg;
ctx.beginPath();
ctx.fillRect(0, 0, size, size);
ctx.fillStyle = colors[rand(colors.length)];
// 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);
// tslint:disable-next-line:prefer-for-of
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);
}