make screenSpaceCameraController zoomFactor public.

CHANGES.md

@@ -1,5 +1,17 @@
 # Change Log
 
+### 1.122 - 2024-08-11
+
+#### @cesium/engine
+
+##### Breaking Changes :mega:
+
+- `ScreenSpaceCameraController._zoomFactor` replaced with public zoomFactor attribute.
+
+##### Additions :tada:
+
+- Exposes `ScreenSpaceCameraController.zoomFactor` to allow adjusting the zoom factor (speed). [#9145](https://github.com/CesiumGS/cesium/pull/9145)
+
 ### 1.121 - 2024-09-01
 
 #### @cesium/engine

CONTRIBUTORS.md

@@ -393,3 +393,4 @@ See [CONTRIBUTING.md](CONTRIBUTING.md) for details on how to contribute to Cesiu
 - [Tim Schneider](https://github.com/Tim-S)
 - [Vladislav Yunev](https://github.com/YunVlad)
 - [Levi Montgomery](https://github.com/Levi-Montgomery)
+- [Brandon Berisford](https://github.com/BeyondBelief96)

packages/engine/Source/Scene/ScreenSpaceCameraController.js

@@ -137,6 +137,14 @@ function ScreenSpaceCameraController(scene) {
    * @default {@link Number.POSITIVE_INFINITY}
    */
   this.maximumZoomDistance = Number.POSITIVE_INFINITY;
+
+  /**
+   * A multiplier for the speed at which the camera will zoom.
+   * @type {Number}
+   * @default 5.0
+   */
+  this.zoomFactor = 5.0;
+
   /**
    * The input that allows the user to pan around the map. This only applies in 2D and Columbus view modes.
    * <p>
@@ -324,7 +332,6 @@ function ScreenSpaceCameraController(scene) {
   );
 
   // Constants, Make any of these public?
-  this._zoomFactor = 5.0;
   this._rotateFactor = undefined;
   this._rotateRateRangeAdjustment = undefined;
   this._maximumRotateRate = 1.77;
@@ -1005,7 +1012,7 @@ function zoom2D(controller, startPosition, movement) {
     controller,
     startPosition,
     movement,
-    controller._zoomFactor,
+    controller.zoomFactor,
     camera.getMagnitude()
   );
 }
@@ -1763,7 +1770,7 @@ function zoomCV(controller, startPosition, movement) {
     controller,
     startPosition,
     movement,
-    controller._zoomFactor,
+    controller.zoomFactor,
     distance
   );
 }
@@ -2363,7 +2370,7 @@ function zoom3D(controller, startPosition, movement) {
     controller,
     startPosition,
     movement,
-    controller._zoomFactor,
+    controller.zoomFactor,
     distance,
     Cartesian3.dot(unitPosition, camera.direction)
   );

packages/engine/Specs/Scene/ScreenSpaceCameraControllerSpec.js

@@ -1978,6 +1978,40 @@ describe("Scene/ScreenSpaceCameraController", function () {
     );
   });
 
+  it("can adjust zoom factor", function () {
+    setUp3D();
+
+    // Zoom out
+    const mouseWheelMovement = -120;
+
+    // Slow zoom
+    const initialPosition = Cartesian3.clone(camera.position);
+    controller.zoomFactor = 1.0;
+    simulateMouseWheel(mouseWheelMovement);
+    updateController();
+    const slowZoomPosition = Cartesian3.clone(camera.position);
+    const slowZoomMagnitude = Cartesian3.magnitude(slowZoomPosition);
+
+    // Medium zoom
+    camera.position = Cartesian3.clone(initialPosition);
+    controller.zoomFactor = 5.0;
+    simulateMouseWheel(mouseWheelMovement);
+    updateController();
+    const mediumZoomPosition = Cartesian3.clone(camera.position);
+    const mediumZoomMagnitude = Cartesian3.magnitude(mediumZoomPosition);
+
+    // Fast zoom
+    camera.position = Cartesian3.clone(initialPosition);
+    controller.zoomFactor = 10.0;
+    simulateMouseWheel(mouseWheelMovement);
+    updateController();
+    const fastZoomPosition = Cartesian3.clone(camera.position);
+    const fastZoomMagnitude = Cartesian3.magnitude(fastZoomPosition);
+
+    expect(fastZoomMagnitude).toBeGreaterThan(mediumZoomMagnitude);
+    expect(mediumZoomMagnitude).toBeGreaterThan(slowZoomMagnitude);
+  });
+
   it("is destroyed", function () {
     expect(controller.isDestroyed()).toEqual(false);
     controller.destroy();