ShimShamSam

function createTree(nodes) {
	const children = {};
	const tree     = [];

	for(const node of nodes) {
		node.children = children[node.id] || (children[node.id] = []);
		(node.parent_id ? children[node.parent_id] || (children[node.parent_id] = []) : tree).push(node);
	}

	return tree;

ShimShamSam

/**
 * Negate sideways velocity on an object being acted upon by a Phaser physics engine.
 * The primary use for this is to simulate vehicle movement by negating "drift" when the vehicle turns.
 * @param {Phaser.Sprite} sprite The sprite whose sideways velocity you want to negate
 */
function stopSidewaysVelocity(sprite) {
	// Recycle the same object to conserve memory
	if(!stopSidewaysVelocity.sideways) {
		stopSidewaysVelocity.sideways = {};
	}