[test] Added Projection tests

2 files changed, 11 insertions, 5 deletions

diff --git a/include/mbgl/util/geo.hpp b/include/mbgl/util/geo.hpp
index 7e15d5c2f1..5db307e482 100644
--- a/include/mbgl/util/geo.hpp
+++ b/include/mbgl/util/geo.hpp
@@ -67,8 +67,8 @@ inline bool operator!=(const LatLng& a, const LatLng& b) {
 
 class ProjectedMeters {
 public:
-    double northing = 0;
-    double easting = 0;
+    double northing;
+    double easting;
 
     ProjectedMeters(double n = 0, double e = 0)
         : northing(n), easting(e) {}
@@ -78,6 +78,10 @@ public:
     }
 };
 
+inline bool operator==(const ProjectedMeters& a, const ProjectedMeters& b) {
+    return a.northing == b.northing && a.easting == b.easting;
+}
+
 class LatLngBounds {
 public:
     // Return a bounds covering the entire (unwrapped) world.
diff --git a/include/mbgl/util/projection.hpp b/include/mbgl/util/projection.hpp
index 8e1c994657..76c60f5cd8 100644
--- a/include/mbgl/util/projection.hpp
+++ b/include/mbgl/util/projection.hpp
@@ -12,19 +12,20 @@ class Projection {
 
 public:
     static inline double getMetersPerPixelAtLatitude(double lat, double zoom) {
-        const double mapPixelWidthAtZoom = std::pow(2.0, zoom) * util::tileSize;
+        const double constrainedZoom = util::clamp(zoom, util::MIN_ZOOM, util::MAX_ZOOM);
+        const double mapPixelWidthAtZoom = std::pow(2.0, constrainedZoom) * util::tileSize;
         const double constrainedLatitude = util::clamp(lat, -util::LATITUDE_MAX, util::LATITUDE_MAX);
-
         return std::cos(constrainedLatitude * util::DEG2RAD) * util::M2PI * util::EARTH_RADIUS_M / mapPixelWidthAtZoom;
     }
 
     static inline ProjectedMeters projectedMetersForLatLng(const LatLng& latLng) {
         const double constrainedLatitude = util::clamp(latLng.latitude, -util::LATITUDE_MAX, util::LATITUDE_MAX);
+        const double constrainedLongitude = util::clamp(latLng.longitude, -util::LONGITUDE_MAX, util::LONGITUDE_MAX);
 
         const double m = 1 - 1e-15;
         const double f = util::clamp(std::sin(util::DEG2RAD * constrainedLatitude), -m, m);
 
-        const double easting  = util::EARTH_RADIUS_M * latLng.longitude * util::DEG2RAD;
+        const double easting  = util::EARTH_RADIUS_M * constrainedLongitude * util::DEG2RAD;
         const double northing = 0.5 * util::EARTH_RADIUS_M * std::log((1 + f) / (1 - f));
 
         return ProjectedMeters(northing, easting);
@@ -35,6 +36,7 @@ public:
         double longitude = projectedMeters.easting * util::RAD2DEG / util::EARTH_RADIUS_M;
 
         latitude = util::clamp(latitude, -util::LATITUDE_MAX, util::LATITUDE_MAX);
+        longitude = util::clamp(longitude, -util::LONGITUDE_MAX, util::LONGITUDE_MAX);
 
         return LatLng(latitude, longitude);
     }