Merge pull request #2603 from gradienthealth/gradienthealth/added_nonlinear_color_transfer_function_param

feat: added nonlinear param to buildFunctionFromTable

Author: floryst

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

@@ -1,3 +1,4 @@
+import vtkDataArray from '../../../Common/Core/DataArray';
 import { vtkObject } from '../../../interfaces';
 import { ColorSpace, Scale } from "./Constants";
 
@@ -201,6 +202,25 @@ export interface vtkColorTransferFunction extends vtkObject {
     withAlpha: boolean
   ): Float32Array;
 
+  /**
+   * Construct a color transfer function from a vtkDataArray.
+   * The order of values depends on the number of components
+   * of the array.
+   * 3 -> RGB
+   * 4 -> XRGB
+   * 5 -> RGBMS
+   * 6 -> XRGBMS
+   * 
+   * X represents the input value to a function
+   * RGB represents the red, green, and blue value output
+   * M represents the midpoint
+   * S represents sharpness
+   * @param {vtkDataArray} array
+   */
+   buildFunctionFromArray(
+    array: vtkDataArray,
+  ): void;
+
   /**
    * Construct a color transfer function from a table.
    * @param {Number} xStart The index of the first point.

Sources/Rendering/Core/ColorTransferFunction/index.js

@@ -871,6 +871,63 @@ function vtkColorTransferFunction(publicAPI, model) {
     return model.table;
   };
 
+  publicAPI.buildFunctionFromArray = (array) => {
+    publicAPI.removeAllPoints();
+    const numComponents = array.getNumberOfComponents();
+    for (let i = 0; i < array.getNumberOfTuples(); i++) {
+      switch (numComponents) {
+        case 3: {
+          model.nodes.push({
+            x: i,
+            r: array.getComponent(i, 0),
+            g: array.getComponent(i, 1),
+            b: array.getComponent(i, 2),
+            midpoint: 0.5,
+            sharpness: 0.0,
+          });
+          break;
+        }
+        case 4: {
+          model.nodes.push({
+            x: array.getComponent(i, 0),
+            r: array.getComponent(i, 1),
+            g: array.getComponent(i, 2),
+            b: array.getComponent(i, 3),
+            midpoint: 0.5,
+            sharpness: 0.0,
+          });
+          break;
+        }
+        case 5: {
+          model.nodes.push({
+            x: i,
+            r: array.getComponent(i, 0),
+            g: array.getComponent(i, 1),
+            b: array.getComponent(i, 2),
+            midpoint: array.getComponent(i, 4),
+            sharpness: array.getComponent(i, 5),
+          });
+          break;
+        }
+        case 6: {
+          model.nodes.push({
+            x: array.getComponent(i, 0),
+            r: array.getComponent(i, 1),
+            g: array.getComponent(i, 2),
+            b: array.getComponent(i, 3),
+            midpoint: array.getComponent(i, 4),
+            sharpness: array.getComponent(i, 5),
+          });
+          break;
+        }
+        default: {
+          break;
+        }
+      }
+    }
+    publicAPI.sortAndUpdateRange();
+  };
+
   //----------------------------------------------------------------------------
   publicAPI.buildFunctionFromTable = (xStart, xEnd, size, table) => {
     let inc = 0.0;