diff options
Diffstat (limited to 'src/mbgl/text/placement.cpp')
| -rw-r--r-- | src/mbgl/text/placement.cpp | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/src/mbgl/text/placement.cpp b/src/mbgl/text/placement.cpp index d6d6e269bc..f5e0be0829 100644 --- a/src/mbgl/text/placement.cpp +++ b/src/mbgl/text/placement.cpp @@ -662,7 +662,25 @@ void Placement::placeSymbolBucket(const BucketPlacementData& params, std::set<ui } } else { - for (const SymbolInstance& symbol : bucket.getSymbols(params.sortKeyRange)) { + auto sortedSymbols = bucket.getSymbols(params.sortKeyRange); + if (auto* previousPlacement = getPrevPlacement()) { + std::stable_sort( + sortedSymbols.begin(), sortedSymbols.end(), [&](const SymbolInstance& a, const SymbolInstance& b) { + auto* aPlacement = previousPlacement->getSymbolPlacement(a); + auto* bPlacement = previousPlacement->getSymbolPlacement(b); + if (!aPlacement) { + // a < b, if 'a' is new and if 'b' was previously hidden. + return bPlacement && !bPlacement->placed(); + } + if (!bPlacement) { + // a < b, if 'b' is new and 'a' was previously shown. + return aPlacement && aPlacement->placed(); + } + // a < b, if 'a' was shown and 'b' was hidden. + return aPlacement->placed() && !bPlacement->placed(); + }); + } + for (const SymbolInstance& symbol : sortedSymbols) { placeSymbol(symbol); } } @@ -1203,6 +1221,13 @@ float Placement::zoomAdjustment(const float zoom) const { return std::max(0.0, (placementZoom - zoom) / 1.5); } +const JointPlacement* Placement::getSymbolPlacement(const SymbolInstance& symbol) const { + assert(symbol.crossTileID != 0); + auto found = placements.find(symbol.crossTileID); + if (found == placements.end()) return nullptr; + return &found->second; +} + Duration Placement::getUpdatePeriod(const float zoom) const { // Even if transitionOptions.duration is set to a value < 300ms, we still wait for this default transition duration // before attempting another placement operation. |