fix collisions in overscaled tiles [skip ci]upstream/start-collision-flicker

2 files changed, 6 insertions, 3 deletions

diff --git a/src/mbgl/text/placement.cpp b/src/mbgl/text/placement.cpp
index d67da53643..3f9ea07d58 100644
--- a/src/mbgl/text/placement.cpp
+++ b/src/mbgl/text/placement.cpp
@@ -51,6 +51,8 @@ void Placement::placeLayer(RenderSymbolLayer& symbolLayer, const mat4& projMatri
 
         const float scale = std::pow(2, state.getZoom() - renderTile.id.canonical.z);
 
+        const float pixelRatio = util::EXTENT / (util::tileSize * renderTile.tile.id.overscaleFactor());
+
         // TODO perf: do this only once for each tile, not once per layer
         state.matrixFor(renderTile.matrix, renderTile.id);
         matrix::multiply(renderTile.matrix, projMatrix, renderTile.matrix);
@@ -67,7 +69,7 @@ void Placement::placeLayer(RenderSymbolLayer& symbolLayer, const mat4& projMatri
                 state,
                 pixelsToTileUnits);
 
-        placeLayerBucket(symbolBucket, renderTile.matrix, textLabelPlaneMatrix, iconLabelPlaneMatrix, scale, showCollisionBoxes);
+        placeLayerBucket(symbolBucket, renderTile.matrix, textLabelPlaneMatrix, iconLabelPlaneMatrix, scale, pixelRatio, showCollisionBoxes);
     }
 }
 
@@ -77,6 +79,7 @@ void Placement::placeLayerBucket(
         const mat4& textLabelPlaneMatrix,
         const mat4& iconLabelPlaneMatrix,
         const float scale,
+        const float pixelRatio,
         const bool showCollisionBoxes) {
 
     // TODO collision debug array clearing
@@ -86,7 +89,6 @@ void Placement::placeLayerBucket(
 
     const bool iconWithoutText = !bucket.hasTextData() || bucket.layout.get<TextOptional>();
     const bool textWithoutIcon = !bucket.hasIconData() || bucket.layout.get<IconOptional>();
-    float pixelRatio = util::EXTENT / util::tileSize;
 
     for (auto& symbolInstance : bucket.symbolInstances) {
 
@@ -108,7 +110,7 @@ void Placement::placeLayerBucket(
 
                 placeText = collisionIndex.placeFeature(symbolInstance.textCollisionFeature,
                         posMatrix, textLabelPlaneMatrix, pixelRatio,
-                        placedSymbol,scale, fontSize,
+                        placedSymbol, scale, fontSize,
                         bucket.layout.get<TextAllowOverlap>(),
                         bucket.layout.get<TextPitchAlignment>() == style::AlignmentType::Map,
                         showCollisionBoxes);
diff --git a/src/mbgl/text/placement.hpp b/src/mbgl/text/placement.hpp
index c694e8ef98..9802ad546b 100644
--- a/src/mbgl/text/placement.hpp
+++ b/src/mbgl/text/placement.hpp
@@ -54,6 +54,7 @@ namespace mbgl {
                     const mat4& textLabelPlaneMatrix,
                     const mat4& iconLabelPlaneMatrix,
                     const float scale,
+                    const float pixelRatio,
                     const bool showCollisionBoxes);
 
             void updateBucketOpacities(SymbolBucket&);