[core] Added Map::latLngBoundsForCamera

src/mbgl/map/map.cpp

@@ -644,6 +644,17 @@ CameraOptions Map::cameraForLatLngs(const std::vector<LatLng>& latLngs, optional
     return options;
 }
 
+LatLngBounds Map::latLngBoundsForCamera(const CameraOptions& camera) const {
+    Transform shallow { impl->transform.getState() };
+    Size size = shallow.getState().getSize();
+
+    shallow.jumpTo(camera);
+    return LatLngBounds::hull(
+        shallow.screenCoordinateToLatLng({}),
+        shallow.screenCoordinateToLatLng({ double(size.width), double(size.height) })
+    );
+}
+
 void Map::resetZoom() {
     impl->cameraMutated = true;
     setZoom(0);

src/mbgl/map/transform.hpp

@@ -22,6 +22,8 @@ public:
               ConstrainMode = ConstrainMode::HeightOnly,
               ViewportMode = ViewportMode::Default);
 
+    Transform(const TransformState &state_) : observer(MapObserver::nullObserver()), state(state_) {}
+
     // Map view
     bool resize(Size size);