feat(input): add DOM event command adapters

input/viewport.ts

@@ -0,0 +1,19 @@
+import type { Dispatch } from "@commands/dispatcher";
+import type { GlobalWheelConsumer, WheelInputEvent } from "./pointer";
+
+export function handleViewportWheel(options: {
+  event: WheelInputEvent;
+  globalConsumer: GlobalWheelConsumer;
+  dispatch: Dispatch;
+  currentZoom: number;
+}): boolean {
+  if (options.globalConsumer(options.event)) return true;
+
+  const zoomFactor = Math.exp(-options.event.delta.y * 0.001);
+  options.dispatch("viewport.zoomAroundPoint", {
+    zoom: options.currentZoom * zoomFactor,
+    point: options.event.position,
+  });
+
+  return true;
+}