Add files

src/graphics/rendering/fps-autoscaler.ts

@@ -0,0 +1,45 @@
+import { Autoscaler as AutoScaler } from '../../helper/autoscaler';
+import { exponentialDecay } from '../../helper/exponential-decay';
+import { settings } from '../settings';
+
+export class FpsAutoscaler extends AutoScaler {
+  private timeSinceLastAdjusment = 0;
+  private exponentialDecayedDeltaTime = 0.0;
+
+  constructor(setters: { [key: string]: (value: number | boolean) => void }) {
+    super(
+      setters,
+      settings.qualityScaling.qualityTargets,
+      settings.qualityScaling.startingTargetIndex,
+      settings.qualityScaling.scalingOptions
+    );
+  }
+
+  public autoscale(lastDeltaTime: DOMHighResTimeStamp) {
+    this.timeSinceLastAdjusment += lastDeltaTime;
+    if (
+      this.timeSinceLastAdjusment >= settings.qualityScaling.adjusmentRateInMilliseconds
+    ) {
+      this.timeSinceLastAdjusment = 0;
+      this.exponentialDecayedDeltaTime = exponentialDecay(
+        this.exponentialDecayedDeltaTime,
+        lastDeltaTime,
+        settings.qualityScaling.deltaTimeResponsiveness
+      );
+
+      if (
+        this.exponentialDecayedDeltaTime <=
+        settings.qualityScaling.targetDeltaTimeInMilliseconds -
+          settings.qualityScaling.deltaTimeError
+      ) {
+        this.increase();
+      } else if (
+        this.exponentialDecayedDeltaTime >
+        settings.qualityScaling.targetDeltaTimeInMilliseconds +
+          settings.qualityScaling.deltaTimeError
+      ) {
+        this.decrease();
+      }
+    }
+  }
+}