[core] fix missing icon collision boxes

port https://github.com/mapbox/mapbox-gl-js/pull/1981

3 files changed, 19 insertions, 11 deletions

diff --git a/package.json b/package.json
index 901519dd4c..93568a2eb9 100644
--- a/package.json
+++ b/package.json
@@ -26,7 +26,7 @@
   ],
   "devDependencies": {
     "aws-sdk": "^2.2.21",
-    "mapbox-gl-test-suite": "mapbox/mapbox-gl-test-suite#1b9035a02f8f23bf72a197c2a8d8f910d935346f",
+    "mapbox-gl-test-suite": "mapbox/mapbox-gl-test-suite#7a17d43bd8482a01dc165de6fff6ae4c33c4fc5d",
     "node-gyp": "^3.2.1",
     "request": "^2.67.0",
     "tape": "^4.2.2"
diff --git a/src/mbgl/text/collision_feature.cpp b/src/mbgl/text/collision_feature.cpp
index a84e75c85a..186fb39b5d 100644
--- a/src/mbgl/text/collision_feature.cpp
+++ b/src/mbgl/text/collision_feature.cpp
@@ -5,7 +5,7 @@ namespace mbgl {
 
 CollisionFeature::CollisionFeature(const std::vector<Coordinate> &line, const Anchor &anchor,
         const float top, const float bottom, const float left, const float right,
-        const float boxScale, const float padding, const bool alongLine) {
+        const float boxScale, const float padding, const bool alongLine, const bool straight) {
 
     if (top == 0 && bottom == 0 && left == 0 && right == 0) return;
 
@@ -22,14 +22,24 @@ CollisionFeature::CollisionFeature(const std::vector<Coordinate> &line, const An
 
         height = std::max(10.0f * boxScale, height);
 
-        bboxifyLabel(line, anchor, length, height);
+        Coordinate anchorPoint(int16_t(anchor.x), int16_t(anchor.y));
+
+        if (straight) {
+            // used for icon labels that are aligned with the line, but don't curve along it
+            const vec2<double> vector = util::unit(vec2<double>(line[anchor.segment + 1] - line[anchor.segment])) * length;
+            const std::vector<Coordinate> newLine({ anchorPoint - vector, anchorPoint + vector });
+            bboxifyLabel(newLine, anchorPoint, 0, length, height);
+        } else {
+            // used for text labels that curve along a line
+            bboxifyLabel(line, anchorPoint, anchor.segment, length, height);
+        }
     } else {
         boxes.emplace_back(anchor, x1, y1, x2, y2, std::numeric_limits<float>::infinity());
     }
 }
 
 void CollisionFeature::bboxifyLabel(const std::vector<Coordinate> &line,
-        const Anchor &anchor, const float labelLength, const float boxSize) {
+        Coordinate &anchorPoint, const int segment, const float labelLength, const float boxSize) {
 
     const float step = boxSize / 2;
     const unsigned int nBoxes = std::floor(labelLength / step);
@@ -38,10 +48,8 @@ void CollisionFeature::bboxifyLabel(const std::vector<Coordinate> &line,
     // box is at the edge of the label.
     const float firstBoxOffset = -boxSize / 2;
 
-    Coordinate anchorPoint = Coordinate{ (int16_t)anchor.x, (int16_t)anchor.y };
-
     Coordinate &p = anchorPoint;
-    int index = anchor.segment + 1;
+    int index = segment + 1;
     float anchorDistance = firstBoxOffset;
 
     // move backwards along the line to the first segment the label appears on
diff --git a/src/mbgl/text/collision_feature.hpp b/src/mbgl/text/collision_feature.hpp
index f112e17d85..a9d227de1b 100644
--- a/src/mbgl/text/collision_feature.hpp
+++ b/src/mbgl/text/collision_feature.hpp
@@ -37,7 +37,7 @@ namespace mbgl {
                     const float boxScale, const float padding, const bool alongLine)
                 : CollisionFeature(line, anchor,
                         shapedText.top, shapedText.bottom, shapedText.left, shapedText.right,
-                        boxScale, padding, alongLine) {}
+                        boxScale, padding, alongLine, false) {}
 
             // for icons
             inline explicit CollisionFeature(const std::vector<Coordinate> &line, const Anchor &anchor,
@@ -45,17 +45,17 @@ namespace mbgl {
                     const float boxScale, const float padding, const bool alongLine)
                 : CollisionFeature(line, anchor,
                         shapedIcon.top, shapedIcon.bottom, shapedIcon.left, shapedIcon.right,
-                        boxScale, padding, alongLine) {}
+                        boxScale, padding, alongLine, true) {}
 
             explicit CollisionFeature(const std::vector<Coordinate> &line, const Anchor &anchor,
                     const float top, const float bottom, const float left, const float right,
-                    const float boxScale, const float padding, const bool alongLine);
+                    const float boxScale, const float padding, const bool alongLine, const bool straight);
 
 
             std::vector<CollisionBox> boxes;
 
         private:
-            void bboxifyLabel(const std::vector<Coordinate> &line, const Anchor &anchor, const float length, const float height);
+            void bboxifyLabel(const std::vector<Coordinate> &line, Coordinate &anchorPoint, const int segment, const float length, const float height);
     };
 } // namespace mbgl