Fix zooming out speed after reaching minimum zoom distance.

CesiumGS · Jan 25, 2022 · 8e313d9 · 8e313d9
1 parent 10112c8
commit 8e313d9
Showing 1 changed file with 5 additions and 3 deletions.
diff --git a/Source/Scene/ScreenSpaceCameraController.js b/Source/Scene/ScreenSpaceCameraController.js
@@ -532,9 +532,12 @@ function handleZoom(
     );
   }
 
+  var diff = movement.endPosition.y - movement.startPosition.y;
+
   // distanceMeasure should be the height above the ellipsoid.
-  // The zoomRate slows as it approaches the surface and stops minimumZoomDistance above it.
-  var minHeight = object.minimumZoomDistance * percentage;
+  // When approaching the surface, the zoomRate slows and stops minimumZoomDistance above it.
+  var approachingSurface = diff > 0;
+  var minHeight = approachingSurface ? object.minimumZoomDistance * percentage : 0;
   var maxHeight = object.maximumZoomDistance;
 
   var minDistance = distanceMeasure - minHeight;
@@ -545,7 +548,6 @@ function handleZoom(
     object._maximumZoomRate
   );
 
-  var diff = movement.endPosition.y - movement.startPosition.y;
   var rangeWindowRatio = diff / object._scene.canvas.clientHeight;
   rangeWindowRatio = Math.min(rangeWindowRatio, object.maximumMovementRatio);
   var distance = zoomRate * rangeWindowRatio;