[core] SymbolBucket updates complete at placement stage

`RenderSymbolLayer` does not have to update dynamic vertices of its buckets, this logic is moved to placement (which is already updates opacity vertices).

* fixes clustering of labels when text variable placement enabled - as assignes `usesVariablePlacement` per bucket
* simplifies the code in `RenderSymbolLayer` (the `RenderSymbolLayer::upload()`	is now omitted).
* symbol buckets are not modified after orchestration finishes

1 files changed, 2 insertions, 5 deletions

diff --git a/src/mbgl/renderer/renderer_impl.cpp b/src/mbgl/renderer/renderer_impl.cpp
index f8e6b65f7f..a809fd843a 100644
--- a/src/mbgl/renderer/renderer_impl.cpp
+++ b/src/mbgl/renderer/renderer_impl.cpp
@@ -345,10 +345,8 @@ void Renderer::Impl::render(const UpdateParameters& updateParameters) {
             placement->setStale();
         }
 
-        if (placementChanged || symbolBucketsChanged) {
-            for (auto it = layersNeedPlacement.rbegin(); it != layersNeedPlacement.rend(); ++it) {
-                placement->updateLayerOpacities(*it);
-            }
+        for (auto it = layersNeedPlacement.rbegin(); it != layersNeedPlacement.rend(); ++it) {
+            placement->updateLayerBuckets(*it, placementChanged || symbolBucketsChanged);
         }
     }
 
@@ -385,7 +383,6 @@ void Renderer::Impl::render(const UpdateParameters& updateParameters) {
 
         UploadParameters uploadParameters{
             updateParameters.transformState,
-            placement->getVariableOffsets(),
             *imageManager,
             *lineAtlas,
         };