From 7ddb5e8d3618048abe2d4e84ca8aee8505967ac7 Mon Sep 17 00:00:00 2001
From: Alexander Bock <mail@alexanderbock.eu>
Date: Fri, 21 Aug 2020 17:17:19 +0200
Subject: [PATCH] Add a dirty flag to only update the layermanager once per
 frame

---
 modules/globebrowsing/src/renderableglobe.cpp | 20 ++++++++++++++++++-
 modules/globebrowsing/src/renderableglobe.h   |  1 +
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/modules/globebrowsing/src/renderableglobe.cpp b/modules/globebrowsing/src/renderableglobe.cpp
index 86ef86bd2e..f8455e5ca8 100644
--- a/modules/globebrowsing/src/renderableglobe.cpp
+++ b/modules/globebrowsing/src/renderableglobe.cpp
@@ -923,6 +923,20 @@ void RenderableGlobe::update(const UpdateData& data) {
         _shadowComponent.update(data);
     }
 
+    // abock (2020-08-21)
+    // This is a bit nasty every since we removed the second update call from the render
+    // loop. The problem is when we enable a new layer, the dirty flags above will be set
+    // to true, but the update method hasn't run yet.  So we need to move the layerManager
+    // update method to the render function call, but we don't want to *actually* update
+    // the layers once per render call; hence this nasty dirty flag
+    //
+    // How it is without in the frame when we enable a layer:
+    //
+    // RenderableGlobe::update() // updated with the old number of layers
+    // // Lua script to enable layer is executed and sets the dirty flags
+    // RenderableGlobe::render() // rendering with the new number of layers but the
+    //                           // LayerManager hasn't updated yet :o
+    _layerManagerDirty = true;
 }
 
 bool RenderableGlobe::renderedWithDesiredData() const {
@@ -955,7 +969,11 @@ void RenderableGlobe::renderChunks(const RenderData& data, RendererTasks&,
 {
     ZoneScoped
 
-    _layerManager.update();
+
+    if (_layerManagerDirty) {
+        _layerManager.update();
+        _layerManagerDirty = false;
+    }
 
     if (_nLayersIsDirty) {
         std::array<LayerGroup*, LayerManager::NumLayerGroups> lgs =
diff --git a/modules/globebrowsing/src/renderableglobe.h b/modules/globebrowsing/src/renderableglobe.h
index 6e7386cd84..4304bc7c60 100644
--- a/modules/globebrowsing/src/renderableglobe.h
+++ b/modules/globebrowsing/src/renderableglobe.h
@@ -289,6 +289,7 @@ private:
     bool _chunkCornersDirty = true;
     bool _nLayersIsDirty = true;
     bool _allChunksAvailable = true;
+    bool _layerManagerDirty = true;
     size_t _iterationsOfAvailableData = 0;
     size_t _iterationsOfUnavailableData = 0;
     Layer* _lastChangedLayer = nullptr;