Add files

src/helper/autoscaler.ts

@@ -0,0 +1,59 @@
+import { clamp } from './clamp';
+import { mix } from './mix';
+
+export class Autoscaler {
+  // can have fractions
+  private index: number;
+
+  constructor(
+    private setters: { [key: string]: (value: number | boolean) => void },
+    private targets: Array<{ [key: string]: number | boolean }>,
+    startingIndex: number,
+    private scalingOptions: {
+      additiveIncrease: number;
+      multiplicativeDecrease: number;
+    }
+  ) {
+    this.index = startingIndex;
+    this.applyScaling();
+  }
+
+  public increase() {
+    this.index += this.scalingOptions.additiveIncrease;
+    this.applyScaling();
+  }
+
+  public decrease() {
+    this.index /= this.scalingOptions.multiplicativeDecrease;
+    this.applyScaling();
+  }
+
+  private applyScaling() {
+    this.index = clamp(this.index, 0, this.targets.length - 1);
+
+    const floor = Math.floor(this.index);
+    const fract = this.index - floor;
+
+    const previousTarget = this.targets[floor];
+    const nextTarget =
+      floor + 1 == this.targets.length ? previousTarget : this.targets[floor + 1];
+
+    const result = {};
+    for (const key in this.setters) {
+      const previous = previousTarget[key];
+      const next = nextTarget[key];
+      let current: number | boolean;
+      if (typeof previous == 'number') {
+        current = mix(previous, next as number, fract);
+      } else {
+        current = next;
+      }
+
+      result[key] = current;
+
+      this.setters[key](current);
+    }
+
+    //InfoText.modifyRecord('quality', result);
+  }
+}