Pixievolt No. 1 Logo Creator's Randomizer.md

Below is the source file powering the Randomize function of Pixievolt No. 1 Logo Creator as of version 2, provided as a companion to this blog post. All rights reserved (not open source).

randomize.mjs

import { fonts, colors, icons, name1stParts, name2ndParts } from "./data.mjs";
export function randomSettings() {
	let textEffects, noOfTextEffects = weightedIndexSelection([5, 40, 40, 15]);
	if (noOfTextEffects == 3) {
		textEffects = [true, true, true];
	} else if (noOfTextEffects == 2) {
		textEffects = [true, true, true];
		textEffects[Math.floor( Math.random() * 3 )] = false;
	} else if (noOfTextEffects == 1) {
		textEffects = [false, false, false];
		textEffects[Math.floor( Math.random() * 3 )] = true;
	} else {
		textEffects = [false, false, false];
	}
	let [italic, smallCaps, textGlow] = textEffects;
	
	let fontWeights = fonts.map(
		smallCaps
		? (font) => { return font.name == "DejaVu Sans" ? 4 : 3; }
		: (font) => { return font.name == "DejaVu Sans" ? 1 : 2; }
	);
	let fontId = weightedIndexSelection(fontWeights);
	let colorId = Math.floor( Math.random() * colors.length );
	let iconId = weightedIndexSelection( icons.map( (icon) => { return icon.cc ? 4 : 3; } ) );
	let name1stPartId = Math.floor( Math.random() * name1stParts.length );
	let name2ndPartId = Math.floor( Math.random() * name2ndParts.length );
	let no = Math.floor( Math.random() * 101 );
	return {fontId, italic, smallCaps, textGlow, colorId,
		iconId, name1stPartId, name2ndPartId, no};
}
function weightedIndexSelection(array) {
	let weightsTotal = array.reduce( (total, weight) => { return total + weight; } );
	let key = Math.floor( Math.random() * weightsTotal );
	for (let i = 0; i < array.length; ++i) {
		if ( key < array[i] ) {
			return i;
		} else {
			key -= array[i];
		}
	}
}