feat(VolumeMapper): support updating image regions

Sources/Rendering/Core/VolumeMapper/index.d.ts

@@ -1,8 +1,16 @@
 import vtkPiecewiseFunction from "../../../Common/DataModel/PiecewiseFunction";
-import { Bounds, Range } from "../../../types";
+import { Bounds, Range, Vector3 } from "../../../types";
 import vtkAbstractMapper3D, { IAbstractMapper3DInitialValues } from "../AbstractMapper3D";
 import { BlendMode, FilterMode } from "./Constants";
 
+/**
+ * Represents a 3D region of a volume.
+ */
+export interface VolumeRegion {
+  start: Vector3;
+  size: Vector3;
+}
+
 /**
  *
  */
@@ -278,6 +286,25 @@ export interface vtkVolumeMapper extends vtkAbstractMapper3D {
 	 */
 	setLAOKernelRadius(LAOKernelRadius: number): void;
 
+  /**
+   * Tells the mapper to only update the specified regions.
+   * 
+   * If there are zero regions, the mapper updates the entire volume texture.
+   * Otherwise, the mapper will only update the texture by the specified regions
+   * during the next render call.
+   * 
+   * This array is cleared after a successful render.
+   * @param regions 
+   */
+  setRegionsToUpdate(regions: VolumeRegion[]): boolean;
+
+  /**
+   * Retrieves the regions to update.
+   * 
+   * This array is cleared after every successful render.
+   */
+  getRegionsToUpdate(): VolumeRegion[];
+
 	/**
 	 *
 	 */

Sources/Rendering/Core/VolumeMapper/index.js

@@ -141,7 +141,7 @@ function vtkVolumeMapper(publicAPI, model) {
 // ----------------------------------------------------------------------------
 
 // TODO: what values to use for averageIPScalarRange to get GLSL to use max / min values like [-Math.inf, Math.inf]?
-const DEFAULT_VALUES = {
+const defaultValues = (initialValues) => ({
   bounds: [1, -1, 1, -1, 1, -1],
   sampleDistance: 1.0,
   imageSampleDistance: 1.0,
@@ -163,12 +163,14 @@ const DEFAULT_VALUES = {
   localAmbientOcclusion: false,
   LAOKernelSize: 15,
   LAOKernelRadius: 7,
-};
+  regionsToUpdate: [],
+  ...initialValues,
+});
 
 // ----------------------------------------------------------------------------
 
 export function extend(publicAPI, model, initialValues = {}) {
-  Object.assign(model, DEFAULT_VALUES, initialValues);
+  Object.assign(model, defaultValues(initialValues));
 
   vtkAbstractMapper3D.extend(publicAPI, model, initialValues);
 
@@ -190,6 +192,7 @@ export function extend(publicAPI, model, initialValues = {}) {
     'localAmbientOcclusion',
     'LAOKernelSize',
     'LAOKernelRadius',
+    'regionsToUpdate',
   ]);
 
   macro.setGetArray(publicAPI, model, ['ipScalarRange'], 2);