Chore: Restructure Repository for SvelteKit

_old/features/reader/lib/pinchZoom.ts

@@ -0,0 +1,43 @@
+import { createPinchGesture } from "@core/ui/touchscreen";
+import { clampZoom } from "./zoomHelpers";
+import { ZOOM_MIN, ZOOM_MAX } from "../store/readerState.svelte";
+
+export interface PinchTrackerOptions {
+  getZoom:         () => number;
+  setZoom:         (z: number) => void;
+  getInspectScale: () => number;
+  setInspectScale: (s: number) => void;
+  resetInspectPan: () => void;
+  isLongstrip:     () => boolean;
+}
+
+export type { PinchGesture as PinchTracker } from "@core/ui/touchscreen";
+
+const INSPECT_ZOOM_MAX = 8;
+
+export function createPinchTracker(opts: PinchTrackerOptions) {
+  let startZoom    = 0;
+  let startInspect = 0;
+
+  return createPinchGesture({
+    onPinch(scale) {
+      if (startZoom === 0) {
+        startZoom    = opts.getZoom();
+        startInspect = opts.getInspectScale();
+      }
+      if (opts.isLongstrip()) {
+        opts.setZoom(clampZoom(startZoom * scale));
+      } else {
+        const next = Math.max(1, Math.min(INSPECT_ZOOM_MAX, startInspect * scale));
+        if (next !== opts.getInspectScale()) {
+          if (next === 1) opts.resetInspectPan();
+          opts.setInspectScale(next);
+        }
+      }
+    },
+    onPinchEnd() {
+      startZoom    = 0;
+      startInspect = 0;
+    },
+  });
+}