[core] Clear tile pyramid for custom source only if there is a significant change

Clear tile pyramid only if updated source has different tile options,
zoom range or initialization state for a custom tile loader.

1 files changed, 8 insertions, 1 deletions

diff --git a/src/mbgl/renderer/sources/render_custom_geometry_source.cpp b/src/mbgl/renderer/sources/render_custom_geometry_source.cpp
index ea6f5c3102..a54802b21b 100644
--- a/src/mbgl/renderer/sources/render_custom_geometry_source.cpp
+++ b/src/mbgl/renderer/sources/render_custom_geometry_source.cpp
@@ -23,7 +23,14 @@ void RenderCustomGeometrySource::update(Immutable<style::Source::Impl> baseImpl_
                                  const TileParameters& parameters) {
     if (baseImpl != baseImpl_) {
         std::swap(baseImpl, baseImpl_);
-        tilePyramid.clearAll();
+
+        // Clear tile pyramid only if updated source has different tile options,
+        // zoom range or initialization state for a custom tile loader.
+        auto newImpl = staticImmutableCast<style::CustomGeometrySource::Impl>(baseImpl);
+        auto currentImpl = staticImmutableCast<style::CustomGeometrySource::Impl>(baseImpl_);
+        if (*newImpl != *currentImpl) {
+            tilePyramid.clearAll();
+        }
     }
 
     enabled = needsRendering;