From 476b547d3b8ab4586a44495f15096037051a580e Mon Sep 17 00:00:00 2001
From: Jo-Byr <jonathanbouyer24@gmail.com>
Date: Thu, 16 Jul 2026 13:00:03 +0200
Subject: [PATCH] chore(InteractorStyleMPRSlice): fix recursion error in
 example

Limit slice widget update in example to prevent recursion
error between the controller and interactor style
---
 .../InteractorStyleMPRSlice/example/index.js  | 61 +++++++++----------
 .../Style/InteractorStyleMPRSlice/index.js    |  4 ++
 2 files changed, 34 insertions(+), 31 deletions(-)

diff --git a/Sources/Interaction/Style/InteractorStyleMPRSlice/example/index.js b/Sources/Interaction/Style/InteractorStyleMPRSlice/example/index.js
index 13e59ad9217..f06a097c3a3 100644
--- a/Sources/Interaction/Style/InteractorStyleMPRSlice/example/index.js
+++ b/Sources/Interaction/Style/InteractorStyleMPRSlice/example/index.js
@@ -26,35 +26,6 @@ renderWindow.getInteractor().setInteractorStyle(istyle);
 global.fullScreen = fullScreenRenderWindow;
 global.renderWindow = renderWindow;
 
-// ----------------------------------------------------------------------------
-// Volume rendering
-// ----------------------------------------------------------------------------
-
-const actor = vtkVolume.newInstance();
-const mapper = vtkVolumeMapper.newInstance();
-actor.setMapper(mapper);
-
-const reader = vtkHttpDataSetReader.newInstance({
-  fetchGzip: true,
-});
-reader
-  .setUrl(`${__BASE_PATH__}/data/volume/headsq.vti`, { loadData: true })
-  .then(() => {
-    const data = reader.getOutputData();
-
-    mapper.setInputData(data);
-
-    // set interactor style volume mapper after mapper sets input data
-    istyle.setVolumeMapper(mapper);
-    istyle.setSliceNormal(0, 0, 1);
-
-    const range = istyle.getSliceRange();
-    istyle.setSlice((range[0] + range[1]) / 2);
-
-    renderer.addVolume(actor);
-    renderWindow.render();
-  });
-
 // ----------------------------------------------------------------------------
 // UI (lil-gui)
 // ----------------------------------------------------------------------------
@@ -95,5 +66,33 @@ function updateUI() {
   sliceCtrl.updateDisplay?.();
 }
 
-istyle.onModified(updateUI);
-updateUI();
+// ----------------------------------------------------------------------------
+// Volume rendering
+// ----------------------------------------------------------------------------
+
+const actor = vtkVolume.newInstance();
+const mapper = vtkVolumeMapper.newInstance();
+actor.setMapper(mapper);
+
+const reader = vtkHttpDataSetReader.newInstance({
+  fetchGzip: true,
+});
+reader
+  .setUrl(`${__BASE_PATH__}/data/volume/headsq.vti`, { loadData: true })
+  .then(() => {
+    const data = reader.getOutputData();
+
+    mapper.setInputData(data);
+
+    // set interactor style volume mapper after mapper sets input data
+    istyle.setVolumeMapper(mapper);
+    istyle.setSliceNormal(0, 0, 1);
+
+    const range = istyle.getSliceRange();
+    istyle.setSlice((range[0] + range[1]) / 2);
+
+    renderer.addVolume(actor);
+    renderWindow.render();
+    istyle.onModified(updateUI);
+    updateUI();
+  });
diff --git a/Sources/Interaction/Style/InteractorStyleMPRSlice/index.js b/Sources/Interaction/Style/InteractorStyleMPRSlice/index.js
index d861374ec6d..8dfe3cb8897 100644
--- a/Sources/Interaction/Style/InteractorStyleMPRSlice/index.js
+++ b/Sources/Interaction/Style/InteractorStyleMPRSlice/index.js
@@ -137,6 +137,9 @@ function vtkInteractorStyleMPRSlice(publicAPI, model) {
   };
 
   publicAPI.setSlice = (slice) => {
+    if (publicAPI.getSlice() === slice) {
+      return false;
+    }
     const renderer = model._interactor.getCurrentRenderer();
     const camera = renderer.getActiveCamera();
 
@@ -171,6 +174,7 @@ function vtkInteractorStyleMPRSlice(publicAPI, model) {
       camera.setPosition(...newPos);
       camera.setFocalPoint(...slicePoint);
     }
+    return true;
   };
 
   publicAPI.getSliceRange = () => {