Fix line label interpolation offset.

3 files changed, 8 insertions, 12 deletions

diff --git a/src/mbgl/geometry/resample.cpp b/src/mbgl/geometry/resample.cpp
index 2fd4a8fd88..ed086fefd4 100644
--- a/src/mbgl/geometry/resample.cpp
+++ b/src/mbgl/geometry/resample.cpp
@@ -17,17 +17,17 @@ const std::array<std::vector<float>, 4> minScaleArrays = {{
 
 Anchors resample(const std::vector<Coordinate> &vertices, float spacing,
                  const float /*minScale*/, float maxScale, const float tilePixelRatio,
-                 int offset) {
+                 float offset) {
 
     maxScale = std::round(std::fmax(std::fmin(8.0f, maxScale / 2.0f), 1.0f));
     spacing *= tilePixelRatio / maxScale;
-    offset *= tilePixelRatio / maxScale;
+    offset *= tilePixelRatio;
     const size_t index = util::clamp<size_t>(std::floor(std::log(maxScale) / std::log(2)), 0, minScaleArrays.size() - 1);
     const std::vector<float> &minScales = minScaleArrays[index];
     const size_t len = minScales.size();
 
-    float distance = spacing - offset;;
-    float markedDistance = 0.0f;
+    float distance = 0.0f;
+    float markedDistance = offset != 0.0f ? offset - spacing : offset;
     int added = 0;
 
     Anchors points;
diff --git a/src/mbgl/geometry/resample.hpp b/src/mbgl/geometry/resample.hpp
index febb6360d5..ce7eba2f1b 100644
--- a/src/mbgl/geometry/resample.hpp
+++ b/src/mbgl/geometry/resample.hpp
@@ -7,7 +7,7 @@
 namespace mbgl {
 
 Anchors resample(const std::vector<Coordinate> &vertices, float spacing,
-                 float minScale, float maxScale, float tilePixelRatio, int offset);
+                 float minScale, float maxScale, float tilePixelRatio, float offset);
 }
 
 #endif
diff --git a/src/mbgl/renderer/symbol_bucket.cpp b/src/mbgl/renderer/symbol_bucket.cpp
index 9d9636b399..44cc3816a3 100644
--- a/src/mbgl/renderer/symbol_bucket.cpp
+++ b/src/mbgl/renderer/symbol_bucket.cpp
@@ -238,8 +238,7 @@ void SymbolBucket::addFeature(const std::vector<Coordinate> &line, const Shaping
     Anchors anchors;
 
     if (properties.placement == PlacementType::Line) {
-        float textResampleOffset = 0;
-        float iconResampleOffset = 0;
+        float resampleOffset = 0;
 
         if (shaping.size()) {
             float minX = std::numeric_limits<float>::infinity();
@@ -249,15 +248,12 @@ void SymbolBucket::addFeature(const std::vector<Coordinate> &line, const Shaping
                 maxX = std::max(maxX, glyph.x);
             }
             const float labelLength = maxX - minX;
-            textResampleOffset = (labelLength / 2.0 + glyphSize) * fontScale;
-        }
-        if (image) {
-            iconResampleOffset = image.w;
+            resampleOffset = (labelLength / 2.0 + glyphSize * 2.0) * fontScale;
         }
 
         // Line labels
         anchors = resample(line, properties.min_distance, minScale, collision.maxPlacementScale,
-                           collision.tilePixelRatio, std::max(iconResampleOffset, textResampleOffset));
+                           collision.tilePixelRatio, resampleOffset);
 
         // Sort anchors by segment so that we can start placement with the
         // anchors that can be shown at the lowest zoom levels.