90 percent fixed

packages/libs/components/src/map/SemanticMarkers.tsx

@@ -64,7 +64,7 @@ export default function SemanticMarkers({
     // 2023-11: it does seem to be needed for zoom-in animation to work.
     const debouncedUpdateMarkerPositions = debounce(
       updateMarkerPositions,
-      1000
+      animation ? animation.duration : 0
     );
     // call it at least once at the beginning of the life cycle
     debouncedUpdateMarkerPositions();
@@ -126,27 +126,23 @@ export default function SemanticMarkers({
       ) {
         // get the position-modified markers from `animationFunction`
         // see geohash.tsx for example
-        const animationValues = animation.animationFunction({
-          prevMarkers: prevRecenteredMarkers,
-          markers: recenteredMarkers,
-        });
+        const { markers: oldAndNewRepositionedMarkers } =
+          animation.animationFunction({
+            prevMarkers: prevRecenteredMarkers,
+            markers: recenteredMarkers,
+          });
         // set them as current
         // any marker that already existed will move to the modified position
         if (
           !isEqual(
-            animationValues.markers.map(({ props }) => props),
+            oldAndNewRepositionedMarkers.map(({ props }) => props),
             consolidatedMarkers.map(({ props }) => props)
           )
         )
-          setConsolidatedMarkers(animationValues.markers);
-        // then set a timer to remove the old markers when zooming out
-        // or if zooming in, switch to just the new markers straight away
-        // (their starting position was set by `animationFunction`)
-        // It's complicated but it works!
-        timeoutVariable = enqueueZoom(
-          animationValues.zoomType,
-          recenteredMarkers
-        );
+          setConsolidatedMarkers(oldAndNewRepositionedMarkers);
+
+        // we used to set a timer to remove the old markers when zooming out
+        // but now we just let the next render cycle do it.
       } else {
         /** First render of markers **/
         if (
@@ -171,27 +167,6 @@ export default function SemanticMarkers({
       )
         setPrevRecenteredMarkers(recenteredMarkers);
     }
-
-    function enqueueZoom(
-      zoomType: string | null,
-      nextMarkers: ReactElement<BoundsDriftMarkerProps>[]
-    ) {
-      /** If we are zooming in then reset the marker elements. When initially rendered
-       * the new markers will start at the matching existing marker's location and here we will
-       * reset marker elements so they will animated to their final position
-       **/
-      if (zoomType === 'in') {
-        setConsolidatedMarkers(nextMarkers);
-      } else if (zoomType === 'out') {
-        /** If we are zooming out then remove the old markers after they finish animating. **/
-        return window.setTimeout(
-          () => {
-            setConsolidatedMarkers(nextMarkers);
-          },
-          animation ? animation.duration : 0
-        );
-      }
-    }
   }, [
     animation,
     map,

packages/libs/components/src/map/animation_functions/geohash.tsx

@@ -22,9 +22,9 @@ export default function geohashAnimation({
   if (prevGeoHash.length > currentGeohash.length) {
     zoomType = 'out';
     const hashDif = prevGeoHash.length - currentGeohash.length;
-    // Get a new array of existing markers with new position property
+    // Get array of old markers with new positions
     const cloneArray = updateMarkers(prevMarkers, markers, hashDif);
-    // Combine the new and existing markers
+    // Combine the new and old markers
     consolidatedMarkers = [...markers, ...cloneArray];
   } else if (prevGeoHash.length < currentGeohash.length) {
     /** Zoom In - New markers start at old position
@@ -33,10 +33,9 @@ export default function geohashAnimation({
      **/
     zoomType = 'in';
     const hashDif = currentGeohash.length - prevGeoHash.length;
-    // Get a new array of new markers with existing position property
-    // Set final render markers to the cloneArray which holds the new markers with
-    // their new starting location
-    consolidatedMarkers = updateMarkers(markers, prevMarkers, hashDif);
+    // Get array of new markers with old positions
+    const cloneArray = updateMarkers(markers, prevMarkers, hashDif);
+    consolidatedMarkers = [...prevMarkers, ...cloneArray];
   } else {
     /** No difference in geohashes - Render markers as they are **/
     zoomType = null;

packages/libs/components/src/map/animation_functions/updateMarkers.tsx

@@ -22,6 +22,9 @@ export default function updateMarkers(
       // Clone marker element with new position
       markerCloneProps = {
         position: matchingMarkers[0].props.position,
+        // ideally we would put the modified markers on top
+        // but this doesn't seem to work:
+        // zIndexOffset: -1000, // or +1000
       };
     }