Create stub concrete lockstep engine

src/Game/GameComponents.ts

@@ -1,6 +1,10 @@
-import { Layer, DrawSet } from "../Applet/Render";
-import { SparseStore } from "../Ecs/Data";
+import { KeyName } from "../Applet/Keyboard";
+import { DrawSet, Layer } from "../Applet/Render";
 import { Data as EcsData } from "../Ecs/Components";
+import { copy, SparseStore } from "../Ecs/Data";
+import { DumbMotion } from "../Ecs/Location";
+import { INPUT_FREQUENCY, LockstepProcessor } from "../Ecs/Lockstep";
+import { Buttons } from "./Input";
 
 export enum GamePhase {
     TITLE,
@@ -110,3 +114,26 @@ export class Message {
         public timeout = 3
     ) {}
 }
+
+export class Engine implements LockstepProcessor<KeyName[], Data> {
+    cloneState(old: Data) {
+        return new Data(old);
+    }
+
+    compareInput(a: KeyName[], b: KeyName[]): boolean {
+        if (a.length != b.length) return false;
+
+        let matches = true;
+        a.forEach((keyA, i) => {
+            if (keyA != b[i]) {
+                matches = false;
+            }
+        });
+
+        return matches;
+    }
+
+    advanceState(state: Data, input: KeyName[]) {
+        DumbMotion(state, INPUT_FREQUENCY);
+    }
+}