build: decouple package deps and introduce yarn workspaces (#7415)

* feat: decouple package deps and introduce yarn workspaces

* update root directory

* fix

* fix scripts

* fix lint

* update path in scripts

* remove yarn.lock files from packages

* ignore workspace

* dummy

* dummy

* remove comment check

* revert workflow changes

* ignore ws when installing gh actions

* remove log

* update path

* fix

* fix typo

packages/excalidraw/scene/zoom.ts

@@ -0,0 +1,40 @@
+import { MIN_ZOOM } from "../constants";
+import { AppState, NormalizedZoomValue } from "../types";
+
+export const getNormalizedZoom = (zoom: number): NormalizedZoomValue => {
+  return Math.max(MIN_ZOOM, Math.min(zoom, 30)) as NormalizedZoomValue;
+};
+
+export const getStateForZoom = (
+  {
+    viewportX,
+    viewportY,
+    nextZoom,
+  }: {
+    viewportX: number;
+    viewportY: number;
+    nextZoom: NormalizedZoomValue;
+  },
+  appState: AppState,
+) => {
+  const appLayerX = viewportX - appState.offsetLeft;
+  const appLayerY = viewportY - appState.offsetTop;
+
+  const currentZoom = appState.zoom.value;
+
+  // get original scroll position without zoom
+  const baseScrollX = appState.scrollX + (appLayerX - appLayerX / currentZoom);
+  const baseScrollY = appState.scrollY + (appLayerY - appLayerY / currentZoom);
+
+  // get scroll offsets for target zoom level
+  const zoomOffsetScrollX = -(appLayerX - appLayerX / nextZoom);
+  const zoomOffsetScrollY = -(appLayerY - appLayerY / nextZoom);
+
+  return {
+    scrollX: baseScrollX + zoomOffsetScrollX,
+    scrollY: baseScrollY + zoomOffsetScrollY,
+    zoom: {
+      value: nextZoom,
+    },
+  };
+};