Reduce temporary collections creation in updatePointerPositions

compose/ui/ui/src/skikoMain/kotlin/androidx/compose/ui/ComposeScene.skiko.kt

@@ -493,15 +493,20 @@ class ComposeScene internal constructor(
     }
 
     private fun updatePointerPositions(event: PointerInputEvent) {
-        // touches/styluses positions should be removed from [pointerPositions] if they are not down anymore
-        val releasedPointers = event.pointers.filter { it.type != PointerType.Mouse && !it.down }
-        for (pointer in releasedPointers) {
-            pointerPositions.remove(pointer.id)
-        }
         // update positions for pointers that are down + mouse
-        val pointersToUpdate = event.pointers - releasedPointers.toSet()
-        for (pointer in pointersToUpdate) {
-            pointerPositions[pointer.id] = pointer.position
+        for (pointer in event.pointers) {
+            if (pointer.type == PointerType.Mouse || pointer.down) {
+                pointerPositions[pointer.id] = pointer.position
+            }
+        }
+        // touches/styluses positions should be removed from [pointerPositions] if they are not down anymore
+        val iterator = pointerPositions.iterator()
+        while (iterator.hasNext()) {
+            val pointerId = iterator.next().key
+            val pointer = event.pointers.find { it.id == pointerId } ?: continue
+            if (pointer.type != PointerType.Mouse && !pointer.down) {
+                iterator.remove()
+            }
         }
     }