Performance optimizations and refacturing.

js/FrameRateMeasurer.js

@@ -0,0 +1,86 @@
+import FrameRateMeasuredEvent from "./events/FrameRateMeasuredEvent.js";
+
+export default class FrameRateMeasurer
+{
+    constructor(rounds = 100)
+    {
+        this.rounds = rounds;
+        this.round = 0;
+        this.lastTimestamp = undefined;
+        this.frameDurations = [];
+
+        window.requestAnimationFrame(
+            (timestamp) => {
+                this.measureFrameRate(timestamp);
+            }
+        );
+    }
+
+    measureFrameRate(timestamp)
+    {
+        if (this.lastTimestamp !== undefined) {
+            this.round++;
+            this.frameDurations.push(timestamp - this.lastTimestamp);
+
+            this.lastTimestamp = timestamp;
+
+            if (this.round < this.rounds) {
+                window.requestAnimationFrame(
+                    (timestamp) => {
+                        this.measureFrameRate(timestamp);
+                    }
+                );
+            } else {
+                window.dispatchEvent(new FrameRateMeasuredEvent(this.getAverageFrameRate()));
+            }
+        } else {
+            this.round = 0;
+            this.lastTimestamp = timestamp;
+            window.requestAnimationFrame(
+                (timestamp) => {
+                    this.measureFrameRate(timestamp);
+                }
+            );
+        }
+
+        this.lastTimestamp = timestamp
+    }
+
+    getAverageFrameRate()
+    {
+        let frameDurationSum = 0;
+
+        this.frameDurations.forEach(
+            (duration) => {
+                frameDurationSum += duration;
+            }
+        );
+
+        let durationAverage = frameDurationSum / this.frameDurations.length;
+
+        return 1000 / durationAverage;
+    }
+
+    getFrameRate()
+    {
+        const DEFAULT_FRAME_RATES = [30, 60, 120];
+
+        let averageFrameRate = this.getAverageFrameRate();
+        let closestDistance = {frameRate: 0, distance: 99999};
+
+        DEFAULT_FRAME_RATES.forEach(
+            (frameRate) => {
+                let distance = Math.abs(frameRate - averageFrameRate);
+
+                if (closestDistance.distance > distance) {
+                    closestDistance.frameRate = frameRate;
+                    closestDistance.distance = distance;
+                }
+            }
+        );
+
+        console.log(this.frameDurations);
+
+        return closestDistance.frameRate;
+    }
+}