@woosh/meep-engine/src/core/geom/packing/max-rect/findBestContainer.js

Pure JavaScript game engine. Fully featured and production ready.

import { assert } from "../../../assert.js";

/**
 * @template T
 * @param {number} width
 * @param {number} height
 * @param {QuadTreeNode<T>} boxes
 * @param {function(containerWidth:number, containerHeight:number, childWidth:number, childHeight:number):number} costFunction
 * @returns {QuadTreeDatum<T>} suitable container box
 */
export function findBestContainer(
    width,
    height,
    boxes,
    costFunction
) {

    assert.isNumber(width,'width');
    assert.isNumber(height,'height');
    assert.defined(boxes,'boxes');
    assert.isFunction(costFunction,'costFunction');

    let best = null;
    let bestScore = Number.POSITIVE_INFINITY;

    /**
     *
     * @param {QuadTreeNode} node
     * @return {boolean}
     */
    function visitor(node){

        if (node.getWidth() < width) {
            //too small, don't traverse deeper
            return false;
        }

        if (node.getHeight() < height) {
            //too small, don't traverse deeper
            return false;
        }

        const data = node.data;
        const box_count = data.length;

        for (let i = 0; i < box_count; i++) {
            const box = data[i];

            const bW = box.getWidth();

            if (bW < width) {
                //too small
                continue;
            }

            const bH = box.getHeight();

            if (bH < height) {
                //too small
                continue;
            }

            const cost = costFunction(bW, bH, width, height);

            assert.isNumber(cost,'cost');
            assert.notNaN(cost,'cost');

            if (cost < bestScore) {
                bestScore = cost;
                best = box;
            }
        }

        return true;
    }

    boxes.traversePreOrder(visitor);

    return best;
}