fix(ColorTransferFunction): applyColorMap calls modified in more cases

Similar shaped color maps passed to applyColorMap did not always trigger
publicAPI.modified()

Author: PaulHax

Sources/Rendering/Core/ColorTransferFunction/index.js

@@ -1152,6 +1152,7 @@ function vtkColorTransferFunction(publicAPI, model) {
 
   //----------------------------------------------------------------------------
   publicAPI.applyColorMap = (colorMap) => {
+    const oldColorSpace = JSON.stringify(model.colorSpace);
     if (colorMap.ColorSpace) {
       model.colorSpace = ColorSpace[colorMap.ColorSpace.toUpperCase()];
       if (model.colorSpace === undefined) {
@@ -1161,12 +1162,16 @@ function vtkColorTransferFunction(publicAPI, model) {
         model.colorSpace = ColorSpace.RGB;
       }
     }
+
+    const oldNanColor = JSON.stringify(model.nanColor);
     if (colorMap.NanColor) {
       model.nanColor = [].concat(colorMap.NanColor);
       while (model.nanColor.length < 4) {
         model.nanColor.push(1.0);
       }
     }
+
+    const oldNodes = JSON.stringify(model.nodes);
     if (colorMap.RGBPoints) {
       const size = colorMap.RGBPoints.length;
       model.nodes = [];
@@ -1183,13 +1188,19 @@ function vtkColorTransferFunction(publicAPI, model) {
         });
       }
     }
-    // FIXME: not supported ?
-    // if (colorMap.IndexedColors) {
-    // }
-    // if (colorMap.Annotations) {
-    // }
 
-    publicAPI.sortAndUpdateRange();
+    const modifiedInvoked = publicAPI.sortAndUpdateRange();
+
+    if (!modifiedInvoked) {
+      const isModfied = [
+        [oldColorSpace, model.colorSpace],
+        [oldNanColor, model.nanColor],
+        [oldNodes, model.nodes],
+      ].some(([old, current]) => old !== JSON.stringify(current));
+      if (isModfied) publicAPI.modified();
+      return isModfied;
+    }
+    return modifiedInvoked;
   };
 }
 

Sources/Rendering/Core/ColorTransferFunction/test/testColorTransferFunction.js

@@ -9,12 +9,15 @@ import vtkActor from 'vtk.js/Sources/Rendering/Core/Actor';
 import vtkMapper from 'vtk.js/Sources/Rendering/Core/Mapper';
 import vtkDataArray from 'vtk.js/Sources/Common/Core/DataArray';
 import vtkPolyData from 'vtk.js/Sources/Common/DataModel/PolyData';
+import Constants from 'vtk.js/Sources/Rendering/Core/ColorTransferFunction/Constants';
 
 import { areEquals } from 'vtk.js/Sources/Common/Core/Math';
 
 import baseline from './testColorTransferFunction.png';
 import baseline2 from './testColorTransferFunction2.png';
 
+const { ColorSpace } = Constants;
+
 test('Test Color Transfer Function', (t) => {
   const gc = testUtils.createGarbageCollector(t);
   t.ok('rendering', 'vtkMapper ColorTransferFunction');
@@ -159,3 +162,39 @@ test('Test discretized color transfer function', (t) => {
 
   t.end();
 });
+
+test('Test applyColorMap calls modfied', (t) => {
+  const ctf = vtkColorTransferFunction.newInstance();
+
+  const colorMapA = {
+    ColorSpace: ColorSpace.RGB,
+    RGBPoints: [0, 0, 0, 0, 1, 0, 0, 0],
+  };
+  const colorMapB = {
+    ColorSpace: ColorSpace.RGB,
+    RGBPoints: [0, 0, 0, 0, 1, 1, 1, 1],
+  };
+
+  ctf.applyColorMap(colorMapA);
+
+  let isModfied = false;
+  ctf.onModified(() => {
+    isModfied = true;
+  });
+
+  ctf.applyColorMap(colorMapA);
+
+  t.notOk(
+    isModfied,
+    `Expect applyColorMap does not call modified with same color map`
+  );
+
+  ctf.applyColorMap(colorMapB);
+
+  t.ok(
+    isModfied,
+    `Expect applyColorMap calls modified with different color map`
+  );
+
+  t.end();
+});