fix: preclinical mode not working (#5631)

* fix(ViewportWindowLevel): add null checks for volumeActor in opacity functions

* refactor(ViewportWindowLevel): register histogram worker at module load and optimize scalar data retrieval

* fix(Preclinical4D): add null check for viewportId and set frame rate for cine playback

extensions/cornerstone/src/components/ViewportWindowLevel/getViewportVolumeHistogram.ts

@@ -17,9 +17,10 @@ const workerFn = () => {
   });
 };
 
-const getViewportVolumeHistogram = async (viewport, volume, options?) => {
-  workerManager.registerWorker('histogram-worker', workerFn, WorkerOptions);
+// Register worker once at module load time
+workerManager.registerWorker('histogram-worker', workerFn, WorkerOptions);
 
+const getViewportVolumeHistogram = async (viewport, volume, options?) => {
   const volumeImageData = viewport.getImageData(volume.volumeId);
 
   if (!volumeImageData) {
@@ -29,8 +30,7 @@ const getViewportVolumeHistogram = async (viewport, volume, options?) => {
   let scalarData = volume.scalarData;
 
   if (volume.numTimePoints > 1) {
-    const targetTimePoint = volume.numTimePoints - 1; // or any other time point you need
-    scalarData = volume.voxelManager.getTimePointScalarData(targetTimePoint);
+    scalarData = volume.voxelManager.getDimensionGroupScalarData(volume.numTimePoints);
   } else {
     scalarData = volume.voxelManager.getCompleteScalarDataArray();
   }

extensions/cornerstone/src/components/ViewportWindowLevel/utils.ts

@@ -7,6 +7,10 @@ import { getViewportVolumeHistogram } from './getViewportVolumeHistogram';
  * Gets node opacity from volume actor
  */
 export const getNodeOpacity = (volumeActor, nodeIndex) => {
+  if (!volumeActor) {
+    return undefined;
+  }
+
   const volumeOpacity = volumeActor.getProperty().getScalarOpacity(0);
   const nodeValue = [];
 
@@ -19,6 +23,10 @@ export const getNodeOpacity = (volumeActor, nodeIndex) => {
  * Checks if the opacity applied to the PET volume follows a specific pattern
  */
 export const isPetVolumeWithDefaultOpacity = (volumeId: string, volumeActor) => {
+  if (!volumeActor) {
+    return false;
+  }
+
   const volume = cs3DCache.getVolume(volumeId);
 
   if (!volume || volume.metadata.Modality !== 'PT') {
@@ -59,6 +67,10 @@ export const isPetVolumeWithDefaultOpacity = (volumeId: string, volumeActor) =>
  * Checks if volume has constant opacity
  */
 export const isVolumeWithConstantOpacity = volumeActor => {
+  if (!volumeActor) {
+    return false;
+  }
+
   const volumeOpacity = volumeActor.getProperty().getScalarOpacity(0);
   const opacitySize = volumeOpacity.getSize();
   const firstNodeValue = [];
@@ -91,7 +103,7 @@ export const getWindowLevelsData = async (
 
   const volumeIds = (viewport as Types.IBaseVolumeViewport).getAllVolumeIds();
   const viewportProperties = viewport.getProperties();
-  const { voiRange } = viewportProperties;
+  const { voiRange } = viewportProperties || {};
   const viewportVoi = voiRange
     ? {
         windowWidth: voiRange.upper - voiRange.lower,