[core] createTile callback can load optional and required tiles

2 files changed, 6 insertions, 3 deletions

diff --git a/src/mbgl/algorithm/update_renderables.hpp b/src/mbgl/algorithm/update_renderables.hpp
index 22d4205d90..1f58075a58 100644
--- a/src/mbgl/algorithm/update_renderables.hpp
+++ b/src/mbgl/algorithm/update_renderables.hpp
@@ -33,7 +33,7 @@ void updateRenderables(GetTileDataFn getTileData,
         const OverscaledTileID idealDataTileID(dataTileZoom, idealRenderTileID.canonical);
         auto data = getTileData(idealDataTileID);
         if (!data) {
-            data = createTileData(idealDataTileID);
+            data = createTileData(idealDataTileID, true);
             assert(data);
         }
 
diff --git a/src/mbgl/style/source.cpp b/src/mbgl/style/source.cpp
index dcf8278c0d..89701a2e8a 100644
--- a/src/mbgl/style/source.cpp
+++ b/src/mbgl/style/source.cpp
@@ -285,9 +285,12 @@ bool Source::update(const UpdateParameters& parameters) {
     auto getTileDataFn = [this](const OverscaledTileID& dataTileID) -> TileData* {
         return getTileData(dataTileID);
     };
-    auto createTileDataFn = [this, &parameters](const OverscaledTileID& dataTileID) -> TileData* {
+    auto createTileDataFn = [this, &parameters](const OverscaledTileID& dataTileID,
+                                                bool required) -> TileData* {
         if (auto data = createTile(dataTileID, parameters)) {
-            data->getTileSource()->setNecessity(TileSource::Necessity::Required);
+            if (required) {
+                data->getTileSource()->setNecessity(TileSource::Necessity::Required);
+            }
             return tileDataMap.emplace(dataTileID, std::move(data)).first->second.get();
         } else {
             return nullptr;