CloudInvaders/js/utils.js

const randRange = (low, high) => Math.random() * (high - low) + low;
const toRadians = (degrees) => degrees * Math.PI / 180;
const mapNumber = (value, fromLow, fromHigh, toLow, toHigh) => {
    const normalized = (value - fromLow) / (fromHigh - fromLow);
    return normalized * (toHigh - toLow) + toLow;
};

let fps_value = 0;
let fps_frames = 0;
let fps_last_capture = Date.now();
const fps = () => {
    fps_frames++;
    if (Date.now() - fps_last_capture >= 500) {
        fps_value = fps_frames * 2;
        fps_frames = 0;
        fps_last_capture = Date.now();
    }

    return fps_value;
}