From b3d3ab0e31d251cf39dfa78dfbc0661b8819a8ab Mon Sep 17 00:00:00 2001
From: Chris Loer <chris.loer@gmail.com>
Date: Tue, 16 Jan 2018 12:38:27 -0800
Subject: [core] Prevent symbols at the same zoom from sharing a crossTileID.
 Port of GL JS PR #5994. Fixes issue #10844, which would allow multiple
 symbols in a tile to share the same crossTileID as one of their duplicate
 parent-tile symbols. Once the symbols shared a crossTileID, they would
 permanently remain "duplicates" of each other, even after increasing zoom
 level allowed the CrossTileSymbolIndex to distinguish between them.

---
 src/mbgl/text/cross_tile_symbol_index.hpp | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

(limited to 'src/mbgl/text/cross_tile_symbol_index.hpp')

diff --git a/src/mbgl/text/cross_tile_symbol_index.hpp b/src/mbgl/text/cross_tile_symbol_index.hpp
index 995e0061b9..5abcde241c 100644
--- a/src/mbgl/text/cross_tile_symbol_index.hpp
+++ b/src/mbgl/text/cross_tile_symbol_index.hpp
@@ -6,6 +6,7 @@
 #include <mbgl/util/optional.hpp>
 
 #include <map>
+#include <set>
 #include <vector>
 #include <string>
 #include <memory>
@@ -32,7 +33,7 @@ public:
     TileLayerIndex(OverscaledTileID coord, std::vector<SymbolInstance>&, uint32_t bucketInstanceId);
 
     Point<int64_t> getScaledCoordinates(SymbolInstance&, const OverscaledTileID&);
-    void findMatches(std::vector<SymbolInstance>&, const OverscaledTileID&);
+    void findMatches(std::vector<SymbolInstance>&, const OverscaledTileID&, std::set<uint32_t>&);
     
     OverscaledTileID coord;
     uint32_t bucketInstanceId;
@@ -45,7 +46,10 @@ public:
     bool addBucket(const OverscaledTileID&, SymbolBucket&, uint32_t& maxCrossTileID);
     bool removeStaleBuckets(const std::unordered_set<uint32_t>& currentIDs);
 private:
-    std::map<uint8_t,std::map<OverscaledTileID,TileLayerIndex>> indexes;
+    void removeBucketCrossTileIDs(uint8_t zoom, const TileLayerIndex& removedBucket);
+
+    std::map<uint8_t, std::map<OverscaledTileID,TileLayerIndex>> indexes;
+    std::map<uint8_t, std::set<uint32_t>> usedCrossTileIDs;
 };
 
 class CrossTileSymbolIndex {
-- 
cgit v1.2.1