Generating arms

tilttek/heraldry

CoatGenerator::generate() draws a coat from a Generator\Seed:

use Tilttek\Heraldry\Generator\CoatGenerator;
use Tilttek\Heraldry\Generator\Seed;

$seed = Seed::generate();              // 32 bytes from the system's secure source
$hex = $seed->hex();                   // 64 hexadecimal digits, to keep with the arms

$coat = new CoatGenerator()->generate(Seed::fromHex($hex));

Reproducible

The seed keys a Xoshiro256** generator with its SHA-256, and every draw comes from it in a fixed order: the same seed gives the same coat on any server and any PHP of the supported versions. The seed comes from the server: a client that sends a seed only asks for arms already drawn. Seed::fromHex() takes 64 hexadecimal digits and throws Exception\InvalidSeed for anything else.

What it draws

Part	How often
A plain field	3 coats in 5; metals and colours twice as likely as furs
A divided field	2 coats in 5, between a metal or a fur and a colour, in either order
An ordinary	a little more than half the coats
Charges with no ordinary	85 % of those coats, one to three; three in ten groups of two or three take an arrangement
Charges with an ordinary	half of those coats, on it or beside it as the ordinary allows
A mark of difference	one coat in ten

Every coat keeps the rule of tincture; on a divided field, the tincture of what lies on it is none of the field's, and what lies side by side never shares a tincture. new CoatGenerator(furs: false) leaves ermine and vair out of the fields.