From a44b7f1e5ddae61260e55db5b68b10d9aa5e711d Mon Sep 17 00:00:00 2001
From: Mikhail Pozdnyakov <mikhail.pozdnyakov@mapbox.com>
Date: Mon, 3 Jun 2019 15:33:22 +0300
Subject: [core] Avoid unneeded update of symbol dynamic vertex buffer

---
 src/mbgl/renderer/buckets/symbol_bucket.cpp |  9 ++++++---
 src/mbgl/text/placement.cpp                 | 12 ++++++++++--
 src/mbgl/text/placement.hpp                 |  4 ++--
 3 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/src/mbgl/renderer/buckets/symbol_bucket.cpp b/src/mbgl/renderer/buckets/symbol_bucket.cpp
index fe083cca9e..c9dd126181 100644
--- a/src/mbgl/renderer/buckets/symbol_bucket.cpp
+++ b/src/mbgl/renderer/buckets/symbol_bucket.cpp
@@ -257,10 +257,13 @@ void SymbolBucket::updateVertices(Placement& placement, bool updateOpacities, co
     if (updateOpacities) {
         placement.updateBucketOpacities(*this, seenIds);
         placementChangesUploaded = false;
+        uploaded = false;
+    }
+
+    if (placement.updateBucketDynamicVertices(*this, tile)) {
+        dynamicUploaded = false;
+        uploaded = false;
     }
-    placement.updateBucketDynamicVertices(*this, tile);
-    dynamicUploaded = false;
-    uploaded = false;
 }
 
 } // namespace mbgl
diff --git a/src/mbgl/text/placement.cpp b/src/mbgl/text/placement.cpp
index c95df02a41..452a071683 100644
--- a/src/mbgl/text/placement.cpp
+++ b/src/mbgl/text/placement.cpp
@@ -402,17 +402,20 @@ Point<float> calculateVariableRenderShift(style::SymbolAnchorType anchor, float
 }
 } // namespace
 
-void Placement::updateBucketDynamicVertices(SymbolBucket& bucket, const RenderTile& tile) {
+bool Placement::updateBucketDynamicVertices(SymbolBucket& bucket, const RenderTile& tile) {
     using namespace style;
     const auto& layout = bucket.layout;
     const bool alongLine = layout.get<SymbolPlacement>() != SymbolPlacementType::Point;
+    bool result = false;
+
     if (alongLine) {
-        if (bucket.hasIconData() && layout.get<IconRotationAlignment>() == AlignmentType::Map) {                    
+        if (bucket.hasIconData() && layout.get<IconRotationAlignment>() == AlignmentType::Map) {
             const bool pitchWithMap = layout.get<style::IconPitchAlignment>() == style::AlignmentType::Map;
             const bool keepUpright = layout.get<style::IconKeepUpright>();
             reprojectLineLabels(bucket.icon.dynamicVertices, bucket.icon.placedSymbols,
                 tile.matrix, pitchWithMap, true /*rotateWithMap*/, keepUpright,
                 tile, *bucket.iconSizeBinder, state);
+            result = true;
         }
 
         if (bucket.hasTextData() && layout.get<TextRotationAlignment>() == AlignmentType::Map) {
@@ -421,6 +424,7 @@ void Placement::updateBucketDynamicVertices(SymbolBucket& bucket, const RenderTi
             reprojectLineLabels(bucket.text.dynamicVertices, bucket.text.placedSymbols,
                 tile.matrix, pitchWithMap, true /*rotateWithMap*/, keepUpright,
                 tile, *bucket.textSizeBinder, state);
+            result = true;
         }
     } else if (!layout.get<TextVariableAnchor>().empty() && bucket.hasTextData()) {
         bucket.text.dynamicVertices.clear();
@@ -488,7 +492,11 @@ void Placement::updateBucketDynamicVertices(SymbolBucket& bucket, const RenderTi
                 }
             }
         }
+
+        result = true;
     }
+
+    return result;
 }
 
 void Placement::updateBucketOpacities(SymbolBucket& bucket, std::set<uint32_t>& seenCrossTileIDs) {
diff --git a/src/mbgl/text/placement.hpp b/src/mbgl/text/placement.hpp
index a568b6985f..69d05c94db 100644
--- a/src/mbgl/text/placement.hpp
+++ b/src/mbgl/text/placement.hpp
@@ -118,8 +118,8 @@ private:
             SymbolBucket&,
             const BucketPlacementParameters&,
             std::set<uint32_t>& seenCrossTileIDs);
-
-    void updateBucketDynamicVertices(SymbolBucket& bucket, const RenderTile& tile);
+    // Returns `true` if bucket vertices were updated; returns `false` otherwise.
+    bool updateBucketDynamicVertices(SymbolBucket& bucket, const RenderTile& tile);
     void updateBucketOpacities(SymbolBucket&, std::set<uint32_t>&);
     void markUsedJustification(SymbolBucket&, style::TextVariableAnchorType, SymbolInstance&);
 
-- 
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