basic state switching from loading to running to editing

state/states/EditTrackState.ts

@@ -0,0 +1,70 @@
+import { Vector } from "@bearmetal/doodler";
+import { getContextItem, setContextItem } from "../../lib/context.ts";
+import { InputManager } from "../../lib/input.ts";
+import { TrackSystem } from "../../track/system.ts";
+import { State, StateMachine } from "../machine.ts";
+import { States } from "./index.ts";
+
+export class EditTrackState extends State<States> {
+  override name: States = States.EDIT_TRACK;
+  override validTransitions: Set<States> = new Set([
+    States.RUNNING,
+    States.PAUSED,
+  ]);
+
+  private heldEvents: Map<string | number, (() => void) | undefined> =
+    new Map();
+
+  override update(dt: number): void {
+    const inputManager = getContextItem<InputManager>("inputManager");
+    const track = getContextItem<TrackSystem>("track");
+
+    const firstSegment = track.firstSegment;
+    if (firstSegment) {
+      const firstPoint = firstSegment.points[0].copy();
+      const { x, y } = inputManager.getMouseLocation();
+      firstSegment.points.forEach((p, i) => {
+        const relativePoint = Vector.sub(p, firstPoint);
+        p.set(x, y);
+        p.add(relativePoint);
+      });
+    }
+
+    track.draw(true);
+    // TODO
+    // Draw ui
+    // Draw track points
+    // Draw track tangents
+  }
+  override start(): void {
+    const inputManager = getContextItem<InputManager>("inputManager");
+    this.heldEvents.set("e", inputManager.offKey("e"));
+    this.heldEvents.set("Escape", inputManager.offKey("Escape"));
+    inputManager.onKey("e", () => {
+      const state = getContextItem<StateMachine<States>>("state");
+      state.transitionTo(States.RUNNING);
+    });
+
+    const track = getContextItem<TrackSystem>("track");
+    setContextItem("trackCopy", track.copy());
+    inputManager.onKey("Escape", () => {
+      const trackCopy = getContextItem<TrackSystem>("trackCopy");
+      setContextItem("track", trackCopy);
+      const state = getContextItem<StateMachine<States>>("state");
+      state.transitionTo(States.RUNNING);
+    });
+    // TODO
+    // Cache trains and save
+    // Stash track in context
+  }
+  override stop(): void {
+    if (this.heldEvents.size > 0) {
+      for (const [key, cb] of this.heldEvents) {
+        if (cb) {
+          getContextItem<InputManager>("inputManager").onKey(key, cb);
+        }
+        this.heldEvents.delete(key);
+      }
+    }
+  }
+}