refactor(cell): cleanup vtkCell bounds usage

Expose a convenient vtkBoundingBox::getDiagonalLength2() function

Author: finetjul

Sources/Common/DataModel/BoundingBox/api.md

@@ -93,6 +93,10 @@ Return the Max Length of the box
 
 Return the length of the diagonal or null if not valid.
 
+### getDiagonalLength2(bounds[6]) : Number
+
+Return the squared length of the diagonal or null if not valid.
+
 ### inflate(bounds[6], delta)
 
 Expand the Box by delta on each side, the box will grow by

Sources/Common/DataModel/BoundingBox/index.d.ts

@@ -1,6 +1,7 @@
 import { mat4 } from 'gl-matrix';
 import { Bounds, Vector2, Vector3 } from '../../../types';
 import vtkPoints from '../../Core/Points';
+import { Nullable } from '../../../types';
 
 /**
  * Tests whether two bounds equal.
@@ -176,10 +177,16 @@ export function getZRange(bounds: Bounds): Vector2;
 export function getMaxLength(bounds: Bounds): number;
 
 /**
- * Gets the diagonal of the bounding box.
+ * Gets the diagonal length of the bounding box.
  * @param {Bounds} bounds
  */
-export function getDiagonalLength(bounds: Bounds): number;
+export function getDiagonalLength(bounds: Bounds): Nullable<number>;
+
+/**
+ * Gets the squared diagonal length of the bounding box.
+ * @param {Bounds} bounds
+ */
+export function getDiagonalLength2(bounds: Bounds): Nullable<number>;
 
 /**
  * Gets the min point.
@@ -506,10 +513,16 @@ declare class BoundingBox {
   getMaxLength(bounds: Bounds): number;
 
   /**
-   * Gets the diagonal of the bounding box.
+   * Gets the diagonal length of the bounding box.
+   * @param {Bounds} bounds
+   */
+  getDiagonalLength(bounds: Bounds): Nullable<number>;
+
+  /**
+   * Gets the squared diagonal length of the bounding box.
    * @param {Bounds} bounds
    */
-  getDiagonalLength(bounds: Bounds): number;
+  getDiagonalLength2(bounds: Bounds): Nullable<number>;
 
   /**
    * Gets the min point.
@@ -674,6 +687,7 @@ declare const vtkBoundingBox: {
   getLengths: typeof getLengths;
   getMaxLength: typeof getMaxLength;
   getDiagonalLength: typeof getDiagonalLength;
+  getDiagonalLength2: typeof getDiagonalLength2;
   getMinPoint: typeof getMinPoint;
   getMaxPoint: typeof getMaxPoint;
   getXRange: typeof getXRange;

Sources/Common/DataModel/BoundingBox/index.js

@@ -259,14 +259,19 @@ export function getMaxLength(bounds) {
   return l[2];
 }
 
-export function getDiagonalLength(bounds) {
+export function getDiagonalLength2(bounds) {
   if (isValid(bounds)) {
     const l = getLengths(bounds);
-    return Math.sqrt(l[0] * l[0] + l[1] * l[1] + l[2] * l[2]);
+    return l[0] * l[0] + l[1] * l[1] + l[2] * l[2];
   }
   return null;
 }
 
+export function getDiagonalLength(bounds) {
+  const lenght2 = getDiagonalLength2(bounds);
+  return lenght2 !== null ? Math.sqrt(lenght2) : null;
+}
+
 export function getMinPoint(bounds) {
   return [bounds[0], bounds[2], bounds[4]];
 }
@@ -880,6 +885,10 @@ class BoundingBox {
     return getDiagonalLength(this.bounds);
   }
 
+  getDiagonalLength2() {
+    return getDiagonalLength2(this.bounds);
+  }
+
   getMinPoint() {
     return getMinPoint(this.bounds);
   }

Sources/Common/DataModel/Cell/index.js

@@ -1,5 +1,5 @@
 import macro from 'vtk.js/Sources/macros';
-import * as vtkMath from 'vtk.js/Sources/Common/Core/Math';
+import vtkBoundingBox from 'vtk.js/Sources/Common/DataModel/BoundingBox';
 import vtkPoints from 'vtk.js/Sources/Common/Core/Points';
 
 // ----------------------------------------------------------------------------
@@ -40,42 +40,15 @@ function vtkCell(publicAPI, model) {
     }
   };
 
-  publicAPI.getBounds = () => {
-    const nbPoints = model.points.getNumberOfPoints();
-    const x = [];
-    if (nbPoints) {
-      model.points.getPoint(0, x);
-      model.bounds[0] = x[0];
-      model.bounds[1] = x[0];
-      model.bounds[2] = x[1];
-      model.bounds[3] = x[1];
-      model.bounds[4] = x[2];
-      model.bounds[5] = x[2];
-
-      for (let i = 1; i < nbPoints; i++) {
-        model.points.getPoint(i, x);
-        model.bounds[0] = x[0] < model.bounds[0] ? x[0] : model.bounds[0];
-        model.bounds[1] = x[0] > model.bounds[1] ? x[0] : model.bounds[1];
-        model.bounds[2] = x[1] < model.bounds[2] ? x[1] : model.bounds[2];
-        model.bounds[3] = x[1] > model.bounds[3] ? x[1] : model.bounds[3];
-        model.bounds[4] = x[2] < model.bounds[4] ? x[2] : model.bounds[4];
-        model.bounds[5] = x[2] > model.bounds[5] ? x[2] : model.bounds[5];
-      }
-    } else {
-      vtkMath.uninitializeBounds(model.bounds);
-    }
-    return model.bounds;
-  };
+  publicAPI.getBounds = () => model.points.getBounds();
 
   publicAPI.getLength2 = () => {
-    publicAPI.getBounds();
-    let length = 0.0;
-    let diff = 0;
-    for (let i = 0; i < 3; i++) {
-      diff = model.bounds[2 * i + 1] - model.bounds[2 * i];
-      length += diff * diff;
-    }
-    return length;
+    const lengths = vtkBoundingBox.getLengths(publicAPI.getBounds());
+    return (
+      lengths[0] * lengths[0] +
+      lengths[1] * lengths[1] +
+      lengths[2] * lengths[2]
+    );
   };
 
   publicAPI.getParametricDistance = (pcoords) => {