From 1204a654c602250b3a4aaa97b964d99a2a2906c3 Mon Sep 17 00:00:00 2001
From: keiya sasaki <keiya.s.0210@gmail.com>
Date: Thu, 23 Feb 2023 17:32:21 +0900
Subject: [PATCH] perf: improve 3dtiles features calculation on reearth/core
 (#489)

---
 .../engines/Cesium/Feature/Tileset/hooks.ts   | 26 +++++++++++++++++--
 1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/src/core/engines/Cesium/Feature/Tileset/hooks.ts b/src/core/engines/Cesium/Feature/Tileset/hooks.ts
index 1fad29e180..7424628c08 100644
--- a/src/core/engines/Cesium/Feature/Tileset/hooks.ts
+++ b/src/core/engines/Cesium/Feature/Tileset/hooks.ts
@@ -176,16 +176,38 @@ const useFeature = ({
   const tileAppearance = useMemo(() => extractSimpleLayer(layer)?.["3dtiles"], [layer]);
   const tileAppearanceShow = tileAppearance?.show;
   const tileAppearanceColor = tileAppearance?.color;
+
+  // If styles are updated while features are calculating,
+  // we stop calculating features, and reassign styles.
+  const shouldSkipComputing = useRef(false);
   useEffect(() => {
-    cachedFeaturesRef.current.map(f => {
+    shouldSkipComputing.current = true;
+  }, [tileAppearanceShow, tileAppearanceColor]);
+
+  const computeFeatures = useCallback(() => {
+    for (const f of cachedFeaturesRef.current) {
+      if (shouldSkipComputing.current) {
+        break;
+      }
+
       const properties = f.feature.properties;
       if (properties.show !== tileAppearanceShow || properties.color !== tileAppearanceColor) {
         f.feature.properties.color = tileAppearanceColor;
         f.feature.properties.show = tileAppearanceShow;
         attachComputedFeature(f);
       }
-    });
+    }
   }, [tileAppearanceShow, tileAppearanceColor, attachComputedFeature]);
+
+  useEffect(() => {
+    computeFeatures();
+
+    // Computation is stopped, start re-calculating.
+    if (shouldSkipComputing.current) {
+      shouldSkipComputing.current = false;
+      computeFeatures();
+    }
+  }, [computeFeatures]);
 };
 
 export const useHooks = ({