[core] Add unit test for CrossTileSymbolIndex

4 files changed, 91 insertions, 7 deletions

diff --git a/cmake/test-files.cmake b/cmake/test-files.cmake
index f291650238..b2ddc2b36d 100644
--- a/cmake/test-files.cmake
+++ b/cmake/test-files.cmake
@@ -22,8 +22,8 @@ set(MBGL_TEST_FILES
 
     # gl
     test/gl/bucket.test.cpp
-    test/gl/object.test.cpp
     test/gl/context.test.cpp
+    test/gl/object.test.cpp
 
     # include/mbgl
     test/include/mbgl/test.hpp
@@ -111,6 +111,7 @@ set(MBGL_TEST_FILES
     test/style/style_parser.test.cpp
 
     # text
+    test/text/cross_tile_symbol_index.test.cpp
     test/text/glyph_loader.test.cpp
     test/text/glyph_pbf.test.cpp
     test/text/quads.test.cpp
diff --git a/src/mbgl/text/cross_tile_symbol_index.cpp b/src/mbgl/text/cross_tile_symbol_index.cpp
index 779bec283c..177615857f 100644
--- a/src/mbgl/text/cross_tile_symbol_index.cpp
+++ b/src/mbgl/text/cross_tile_symbol_index.cpp
@@ -57,9 +57,7 @@ void TileLayerIndex::findMatches(std::vector<SymbolInstance>& symbolInstances, c
 CrossTileSymbolLayerIndex::CrossTileSymbolLayerIndex() {
 }
 
-uint32_t CrossTileSymbolLayerIndex::maxCrossTileID = 0;
-
-void CrossTileSymbolLayerIndex::addBucket(const OverscaledTileID& coord, SymbolBucket& bucket) {
+void CrossTileSymbolLayerIndex::addBucket(const OverscaledTileID& coord, SymbolBucket& bucket, uint32_t& maxCrossTileID) {
     if (bucket.bucketInstanceId) return;
     bucket.bucketInstanceId = ++maxBucketInstanceId;
 
@@ -149,7 +147,7 @@ bool CrossTileSymbolIndex::addLayer(RenderSymbolLayer& symbolLayer) {
         if (!symbolBucket.bucketInstanceId) {
             symbolBucketsChanged = true;
         }
-        layerIndex.addBucket(renderTile.tile.id, symbolBucket);
+        layerIndex.addBucket(renderTile.tile.id, symbolBucket, maxCrossTileID);
         currentBucketIDs.insert(symbolBucket.bucketInstanceId);
     }
 
diff --git a/src/mbgl/text/cross_tile_symbol_index.hpp b/src/mbgl/text/cross_tile_symbol_index.hpp
index a32430d872..c67cd37e00 100644
--- a/src/mbgl/text/cross_tile_symbol_index.hpp
+++ b/src/mbgl/text/cross_tile_symbol_index.hpp
@@ -42,12 +42,11 @@ public:
 class CrossTileSymbolLayerIndex {
 public:
     CrossTileSymbolLayerIndex();
-    void addBucket(const OverscaledTileID&, SymbolBucket&);
+    void 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;
     uint32_t maxBucketInstanceId = 0;
-    static uint32_t maxCrossTileID;
 };
 
 class CrossTileSymbolIndex {
@@ -59,6 +58,7 @@ public:
     void reset();
 private:
     std::map<std::string, CrossTileSymbolLayerIndex> layerIndexes;
+    uint32_t maxCrossTileID = 0;
 };
 
 } // namespace mbgl
diff --git a/test/text/cross_tile_symbol_index.test.cpp b/test/text/cross_tile_symbol_index.test.cpp
new file mode 100644
index 0000000000..b40827d63e
--- /dev/null
+++ b/test/text/cross_tile_symbol_index.test.cpp
@@ -0,0 +1,85 @@
+#include <mbgl/text/cross_tile_symbol_index.hpp>
+#include <mbgl/renderer/buckets/symbol_bucket.hpp>
+#include <mbgl/test/util.hpp>
+
+using namespace mbgl;
+
+SymbolInstance makeSymbolInstance(float x, float y, std::u16string key) {
+    GeometryCoordinates line;
+    GlyphPositionMap gpm;
+    const std::pair<Shaping, Shaping> shaping(Shaping{}, Shaping{});
+    style::SymbolLayoutProperties::Evaluated layout_;
+    IndexedSubfeature subfeature(0, "", "", 0);
+    Anchor anchor(x, y, 0, 0);
+    return {anchor, line, shaping, {}, layout_, 0, 0, 0, 0, style::SymbolPlacementType::Point, {{0, 0}}, 0, 0, {{0, 0}}, gpm, subfeature, 0, key, 0 };
+}
+
+
+TEST(CrossTileSymbolLayerIndex, addBucket) {
+
+    uint32_t maxCrossTileID = 0;
+    CrossTileSymbolLayerIndex index;
+
+    style::SymbolLayoutProperties::PossiblyEvaluated layout;
+    bool sdfIcons = false;
+    bool iconsNeedLinear = false;
+    bool sortFeaturesByY = false;
+
+
+    OverscaledTileID mainID(6, 0, 6, 8, 8);
+    std::vector<SymbolInstance> mainInstances;
+    mainInstances.push_back(makeSymbolInstance(1000, 1000, u"Detroit"));
+    mainInstances.push_back(makeSymbolInstance(2000, 2000, u"Toronto"));
+    SymbolBucket mainBucket { layout, {}, 16.0f, 1.0f, 0, sdfIcons, iconsNeedLinear, sortFeaturesByY, std::move(mainInstances) };
+    index.addBucket(mainID, mainBucket, maxCrossTileID);
+
+    // Assigned new IDs
+    ASSERT_EQ(mainBucket.symbolInstances.at(0).crossTileID, 1u);
+    ASSERT_EQ(mainBucket.symbolInstances.at(1).crossTileID, 2u);
+
+
+    OverscaledTileID childID(7, 0, 7, 16, 16);
+    std::vector<SymbolInstance> childInstances;
+    childInstances.push_back(makeSymbolInstance(2000, 2000, u"Detroit"));
+    childInstances.push_back(makeSymbolInstance(2000, 2000, u"Windsor"));
+    childInstances.push_back(makeSymbolInstance(3000, 3000, u"Toronto"));
+    childInstances.push_back(makeSymbolInstance(4001, 4001, u"Toronto"));
+    SymbolBucket childBucket { layout, {}, 16.0f, 1.0f, 0, sdfIcons, iconsNeedLinear, sortFeaturesByY, std::move(childInstances) };
+    index.addBucket(childID, childBucket, maxCrossTileID);
+
+    // matched parent tile
+    ASSERT_EQ(childBucket.symbolInstances.at(0).crossTileID, 1u);
+    // does not match because of different key
+    ASSERT_EQ(childBucket.symbolInstances.at(1).crossTileID, 3u);
+    // does not match because of different location
+    ASSERT_EQ(childBucket.symbolInstances.at(2).crossTileID, 4u);
+    // matches with a slightly different location
+    ASSERT_EQ(childBucket.symbolInstances.at(3).crossTileID, 2u);
+
+    OverscaledTileID parentID(5, 0, 5, 4, 4);
+    std::vector<SymbolInstance> parentInstances;
+    parentInstances.push_back(makeSymbolInstance(500, 500, u"Detroit"));
+    SymbolBucket parentBucket { layout, {}, 16.0f, 1.0f, 0, sdfIcons, iconsNeedLinear, sortFeaturesByY, std::move(parentInstances) };
+    index.addBucket(parentID, parentBucket, maxCrossTileID);
+
+    // matched child tile
+    ASSERT_EQ(parentBucket.symbolInstances.at(0).crossTileID, 1u);
+
+    std::unordered_set<uint32_t> currentIDs;
+    currentIDs.insert(mainBucket.bucketInstanceId);
+    index.removeStaleBuckets(currentIDs);
+
+    // grandchild
+    OverscaledTileID grandchildID(8, 0, 8, 32, 32);
+    std::vector<SymbolInstance> grandchildInstances;
+    grandchildInstances.push_back(makeSymbolInstance(4000, 4000, u"Detroit"));
+    grandchildInstances.push_back(makeSymbolInstance(4000, 4000, u"Windsor"));
+    SymbolBucket grandchildBucket { layout, {}, 16.0f, 1.0f, 0, sdfIcons, iconsNeedLinear, sortFeaturesByY, std::move(grandchildInstances) };
+    index.addBucket(grandchildID, grandchildBucket, maxCrossTileID);
+
+    // Matches the symbol in `mainBucket`
+    ASSERT_EQ(grandchildBucket.symbolInstances.at(0).crossTileID, 1u);
+    // Does not match the previous value for Windsor because that tile was removed
+    ASSERT_EQ(grandchildBucket.symbolInstances.at(1).crossTileID, 5u);
+
+}