tsparticles-engine/browser/Core/Utils/QuadTree.js

Easily create highly customizable particle, confetti and fireworks animations and use them as animated backgrounds for your website. Ready to use components available also for React, Vue.js (2.x and 3.x), Angular, Svelte, jQuery, Preact, Riot.js, Inferno.

import { Circle } from "./Circle";
import { Rectangle } from "./Rectangle";
import { getDistance } from "../../Utils/NumberUtils";
export class QuadTree {
    constructor(rectangle, capacity) {
        this.rectangle = rectangle;
        this.capacity = capacity;
        this._subdivide = () => {
            const { x, y } = this.rectangle.position, { width, height } = this.rectangle.size, { capacity } = this;
            for (let i = 0; i < 4; i++) {
                this._subs.push(new QuadTree(new Rectangle(x + (width / 2) * (i % 2), y + (height / 2) * (Math.round(i / 2) - (i % 2)), width / 2, height / 2), capacity));
            }
            this._divided = true;
        };
        this._points = [];
        this._divided = false;
        this._subs = [];
    }
    insert(point) {
        if (!this.rectangle.contains(point.position)) {
            return false;
        }
        if (this._points.length < this.capacity) {
            this._points.push(point);
            return true;
        }
        if (!this._divided) {
            this._subdivide();
        }
        return this._subs.some((sub) => sub.insert(point));
    }
    query(range, check, found) {
        const res = found || [];
        if (!range.intersects(this.rectangle)) {
            return [];
        }
        for (const p of this._points) {
            if (!range.contains(p.position) &&
                getDistance(range.position, p.position) > p.particle.getRadius() &&
                (!check || check(p.particle))) {
                continue;
            }
            res.push(p.particle);
        }
        if (this._divided) {
            for (const sub of this._subs) {
                sub.query(range, check, res);
            }
        }
        return res;
    }
    queryCircle(position, radius, check) {
        return this.query(new Circle(position.x, position.y, radius), check);
    }
    queryRectangle(position, size, check) {
        return this.query(new Rectangle(position.x, position.y, size.width, size.height), check);
    }
}