chore: setup monorepo using preconstruct

packages/core/src/hooks/useViewport.ts

@@ -0,0 +1,18 @@
+import shallow from 'zustand/shallow';
+
+import { useStore } from '../store';
+import { Viewport, ReactFlowState } from '../types';
+
+const viewportSelector = (state: ReactFlowState) => ({
+  x: state.transform[0],
+  y: state.transform[1],
+  zoom: state.transform[2],
+});
+
+function useViewport(): Viewport {
+  const viewport = useStore(viewportSelector, shallow);
+
+  return viewport;
+}
+
+export default useViewport;