only update the render order array when there are changes to tiles

src/mbgl/map/map_context.cpp

@@ -334,6 +334,7 @@ bool MapContext::renderSync(const TransformState& state, const FrameData& frame)
     if (!painter) {
         painter = std::make_unique<Painter>(data);
         painter->setup();
+        painter->updateRenderOrder(*style);
     }
 
     painter->setDebug(data.getDebug());
@@ -400,6 +401,10 @@ void MapContext::setSprite(const std::string& name, std::shared_ptr<const Sprite
 void MapContext::onTileDataChanged() {
     assert(util::ThreadContext::currentlyOn(util::ThreadType::Map));
 
+    if (painter) {
+        painter->updateRenderOrder(*style);
+    }
+
     updateFlags |= Update::Repaint;
     asyncUpdate->send();
 }