Merge pull request #558 from Kitware/lut-data-range-rescale

Lut data range rescale

Author: jourdain

Examples/Applications/VolumeViewer/index.js

@@ -128,6 +128,7 @@ function createViewer(rootContainer, fileContents, options) {
   // Control UI
   const controllerWidget = vtkVolumeController.newInstance({
     size: [400, 150],
+    rescaleColorMap: true,
   });
   const isBackgroundDark = background[0] + background[1] + background[2] < 1.5;
   controllerWidget.setContainer(rootContainer);

Sources/Interaction/UI/VolumeController/index.js

@@ -58,7 +58,9 @@ function vtkVolumeController(publicAPI, model) {
     const dataArray =
       sourceDS.getPointData().getScalars() ||
       sourceDS.getPointData().getArrays()[0];
-    const dataRange = dataArray.getRange();
+    const dataRange = model.rescaleColorMap
+      ? model.colorDataRange
+      : dataArray.getRange();
     const preset = vtkColorMaps.getPresetByName(
       model.el.querySelector('.js-color-preset').value
     );
@@ -196,6 +198,7 @@ function vtkVolumeController(publicAPI, model) {
     model.widget.applyOpacity(piecewiseFunction);
     model.widget.setContainer(widgetContainer);
     model.widget.bindMouseListeners();
+    model.colorDataRange = model.widget.getOpacityRange();
 
     // Attach listeners
     domToggleButton.addEventListener('click', toggleVisibility);
@@ -206,6 +209,11 @@ function vtkVolumeController(publicAPI, model) {
 
     model.widget.onOpacityChange(() => {
       model.widget.applyOpacity(piecewiseFunction);
+      model.colorDataRange = model.widget.getOpacityRange();
+      if (model.rescaleColorMap) {
+        updateColorMapPreset();
+      }
+
       if (!model.renderWindow.getInteractor().isAnimating()) {
         model.renderWindow.render();
       }
@@ -251,6 +259,15 @@ function vtkVolumeController(publicAPI, model) {
     }
   };
 
+  const rescaleColorMap = publicAPI.setRescaleColorMap;
+  publicAPI.setSescaleColorMap = (value) => {
+    if (rescaleColorMap(value)) {
+      updateColorMapPreset();
+      return true;
+    }
+    return false;
+  };
+
   publicAPI.setSize = model.widget.setSize;
   publicAPI.render = model.widget.render;
   publicAPI.onAnimation = model.widget.onAnimation;
@@ -267,6 +284,7 @@ function vtkVolumeController(publicAPI, model) {
 const DEFAULT_VALUES = {
   size: [600, 300],
   expanded: true,
+  rescaleColorMap: false,
 };
 
 // ----------------------------------------------------------------------------
@@ -276,7 +294,7 @@ export function extend(publicAPI, model, initialValues = {}) {
 
   // Object methods
   macro.obj(publicAPI, model);
-  macro.setGet(publicAPI, model, ['actor', 'renderWindow']);
+  macro.setGet(publicAPI, model, ['actor', 'renderWindow', 'rescaleColorMap']);
   macro.get(publicAPI, model, ['widget']);
 
   // Object specific methods

Sources/Interaction/Widgets/PiecewiseGaussianWidget/index.js

@@ -954,6 +954,23 @@ function vtkPiecewiseGaussianWidget(publicAPI, model) {
     piecewiseFunction.sortAndUpdateRange();
   };
 
+  publicAPI.getOpacityRange = (dataRange) => {
+    const rangeToUse = dataRange || model.dataRange;
+    const delta =
+      (rangeToUse[1] - rangeToUse[0]) / (model.opacities.length - 1);
+    let minIndex = model.opacities.length - 1;
+    let maxIndex = 0;
+    for (let index = 0; index < model.opacities.length; index++) {
+      if (model.opacities[index] > 0) {
+        minIndex = Math.min(minIndex, index);
+      }
+      if (model.opacities[index] > 0) {
+        maxIndex = Math.max(maxIndex, index);
+      }
+    }
+    return [rangeToUse[0] + minIndex * delta, rangeToUse[0] + maxIndex * delta];
+  };
+
   // Trigger rendering for any modified event
   publicAPI.onModified(publicAPI.render);
   publicAPI.setSize(...model.size);