Fixes picking issue in low DPR (#128)

* Update scale calculation in getEntityAtPointerEvent to use PlayCanvas's DPR for improved accuracy

* Remove redundant return statement in getEntityAtPointerEvent function to streamline code execution.

Author: marklundin

packages/lib/src/utils/picker.tsx

@@ -53,9 +53,9 @@ const getEntityAtPointerEvent = async (app : AppBase, picker: Picker, rect: DOMR
      const x = e.clientX - rect.left;
      const y = e.clientY - rect.top;
 
-     // Account for canvas scaling
-     const scaleX = canvas.width / rect.width;
-     const scaleY = canvas.height / rect.height;
+     // Scale calculation using PlayCanvas's DPR
+     const scaleX = canvas.width / (rect.width * app.graphicsDevice.maxPixelRatio);
+     const scaleY = canvas.height / (rect.height * app.graphicsDevice.maxPixelRatio);
 
      // prepare the picker and perform picking
      try {
@@ -67,7 +67,6 @@ const getEntityAtPointerEvent = async (app : AppBase, picker: Picker, rect: DOMR
         if (!meshInstance) return null
 
         return meshInstance?.node as Entity;
-        return null
     } catch {
         // The picker can fail if the camera is not active or the canvas is not visible
         return null;