Fix buffering of query box - it was shrinking in the Y axis, rather than growing.

include/util/vector_tile.hpp

@@ -36,7 +36,7 @@ const constexpr std::uint32_t VARIANT_TYPE_BOOL = 7;
 
 // Vector tiles are 4096 virtual pixels on each side
 const constexpr double EXTENT = 4096.0;
-const constexpr double BUFFER = 512.0;
+const constexpr double BUFFER = 128.0;
 }
 }
 }

include/util/web_mercator.hpp

@@ -140,14 +140,19 @@ inline FloatCoordinate toWGS84(const FloatCoordinate &mercator_coordinate)
 }
 
 // Converts a WMS tile coordinate (z,x,y) into a wgs bounding box
-inline void xyzToWGS84(
-    const int x, const int y, const int z, double &minx, double &miny, double &maxx, double &maxy,
-    int mercator_buffer = 0)
+inline void xyzToWGS84(const int x,
+                       const int y,
+                       const int z,
+                       double &minx,
+                       double &miny,
+                       double &maxx,
+                       double &maxy,
+                       int mercator_buffer = 0)
 {
     minx = x * TILE_SIZE - mercator_buffer;
-    miny = (y + 1.0) * TILE_SIZE - mercator_buffer;
+    miny = (y + 1.0) * TILE_SIZE + mercator_buffer;
     maxx = (x + 1.0) * TILE_SIZE + mercator_buffer;
-    maxy = y * TILE_SIZE + mercator_buffer;
+    maxy = y * TILE_SIZE - mercator_buffer;
     // 2^z * TILE_SIZE
     const double shift = (1u << static_cast<unsigned>(z)) * TILE_SIZE;
     pixelToDegree(shift, minx, miny);