refactor(function): cropper center function calculation

Author: rodrigobasilio2022

Sources/Widgets/Widgets3D/ImageCroppingWidget/behavior.js

@@ -5,6 +5,7 @@ import {
   transformVec3,
   handleTypeFromName,
   calculateDirection,
+  calculateCropperCenter,
 } from 'vtk.js/Sources/Widgets/Widgets3D/ImageCroppingWidget/helpers';
 
 export default function widgetBehavior(publicAPI, model) {
@@ -76,14 +77,8 @@ export default function widgetBehavior(publicAPI, model) {
 
         if (type === 'faces') {
           // get center of current crop box
-          const center = [
-            (planes[0] + planes[1]) / 2,
-            (planes[2] + planes[3]) / 2,
-            (planes[4] + planes[5]) / 2,
-          ];
-
-          // manipulator should be a line manipulator
-          const worldCenter = transformVec3(center, indexToWorldT);
+          const worldCenter = calculateCropperCenter(planes, indexToWorldT);
+
           manipulator.setHandleOrigin(worldCenter);
           manipulator.setHandleNormal(
             calculateDirection(model.activeState.getOrigin(), worldCenter)
@@ -100,14 +95,7 @@ export default function widgetBehavior(publicAPI, model) {
           const faceName = edgeAxis.map((i) => AXES[i + 1]).join('');
           const handle = model.widgetState.getStatesWithLabel(faceName)[0];
           // get center of current crop box
-          const center = [
-            (planes[0] + planes[1]) / 2,
-            (planes[2] + planes[3]) / 2,
-            (planes[4] + planes[5]) / 2,
-          ];
-
-          // manipulator should be a line manipulator
-          const worldCenter = transformVec3(center, indexToWorldT);
+          const worldCenter = calculateCropperCenter(planes, indexToWorldT);
 
           manipulator.setHandleNormal(
             calculateDirection(handle.getOrigin(), worldCenter)

Sources/Widgets/Widgets3D/ImageCroppingWidget/helpers.js

@@ -35,6 +35,16 @@ export function handleTypeFromName(name) {
   return 'faces';
 }
 
+export function calculateCropperCenter(planes, transform) {
+  // get center of current crop box
+  const center = [
+    (planes[0] + planes[1]) / 2,
+    (planes[2] + planes[3]) / 2,
+    (planes[4] + planes[5]) / 2,
+  ];
+  return transformVec3(center, transform);
+}
+
 export function calculateDirection(v1, v2) {
   const direction = vec3.create();
   vec3.subtract(direction, v1, v2);