further safety against numerical issues near the horizon

maplibre · Oct 22, 2024 · 338c78b · 338c78b
1 parent 4edc371
commit 338c78b
Showing 1 changed file with 5 additions and 1 deletion.
diff --git a/src/ui/handler_manager.ts b/src/ui/handler_manager.ts
@@ -527,7 +527,11 @@ export class HandlerManager {
         if (this._map.cameraHelper.useGlobeControls && !tr.isPointOnMapSurface(around)) {
             around = tr.centerPoint;
         }
-        const preZoomAroundLoc = tr.screenPointToLocation(panDelta ? around.sub(panDelta) : around);
+        // If we are rotating about the center point, avoid numerical issues near the horizon by using the transform's
+        // center directly, instead of computing it from the screen point
+        const preZoomAroundLoc = around.distSqr(tr.centerPoint) < 1.0e-2 ?
+            tr.center :
+            tr.screenPointToLocation(panDelta ? around.sub(panDelta) : around);
 
         if (!terrain) {
             // Apply zoom, bearing, pitch, roll