implement inertiaZoom in aggregator

CHANGES.md

@@ -6,6 +6,10 @@
 
 #### Major Announcements :loudspeaker:
 
+##### Additions :tada:
+
+- Added smooth zoom with mouse wheel. [#11062](https://github.com/CesiumGS/cesium/pull/11062)
+
 ##### Fixes :wrench:
 
 - Fixed Primitive.getGeometryInstanceAttributes cache acquisition speed. [#11066](https://github.com/CesiumGS/cesium/issues/11066)

packages/engine/Source/Scene/CameraEventAggregator.js

@@ -159,8 +159,7 @@ function listenToWheel(aggregator, modifier) {
 
   aggregator._eventHandler.setInputAction(
     function (delta) {
-      // TODO: magic numbers
-      const arcLength = 15.0 * CesiumMath.toRadians(delta);
+      const arcLength = 7.5 * CesiumMath.toRadians(delta);
       pressTime[key] = releaseTime[key] = new Date();
       movement.endPosition.x = 0.0;
       movement.endPosition.y = arcLength;

packages/engine/Source/Scene/ScreenSpaceCameraController.js

@@ -591,9 +591,9 @@ function handleZoom(
     return;
   }
 
-  const sameStartPosition = Cartesian2.equals(
-    startPosition,
-    object._zoomMouseStart
+  const sameStartPosition = defaultValue(
+    movement.inertiaEnabled,
+    Cartesian2.equals(startPosition, object._zoomMouseStart)
   );
   let zoomingOnVector = object._zoomingOnVector;
   let rotatingZoom = object._rotatingZoom;
@@ -2162,6 +2162,7 @@ function zoom3D(controller, startPosition, movement) {
   if (defined(movement.distance)) {
     movement = movement.distance;
   }
+  const inertiaMovement = movement.inertiaEnabled;
 
   const ellipsoid = controller._ellipsoid;
   const scene = controller._scene;
@@ -2187,7 +2188,13 @@ function zoom3D(controller, startPosition, movement) {
     camera.position,
     zoom3DCartographic
   ).height;
-  if (height < controller._minimumPickingTerrainHeight) {
+
+  const inertiaMovementApproachingGround = Math.abs(height) < 50;
+
+  const needPickGlobe = inertiaMovement
+    ? inertiaMovementApproachingGround
+    : height < controller._minimumPickingTerrainHeight;
+  if (needPickGlobe) {
     intersection = pickGlobe(controller, windowPosition, zoomCVIntersection);
   }