Began working on distance from location code

scwx-qt/source/scwx/qt/util/geographic_lib.cpp

@@ -5,14 +5,16 @@
 
 #include <GeographicLib/Gnomonic.hpp>
 #include <geos/algorithm/PointLocation.h>
+#include <geos/algorithm/distance/PointPairDistance.h>
+#include <geos/algorithm/distance/DistanceToPoint.h>
 #include <geos/geom/CoordinateSequence.h>
+#include <geos/geom/GeometryFactory.h>
 
 namespace scwx
 {
 namespace qt
 {
-namespace util
-{
+namespace util {
 namespace GeographicLib
 {
 
@@ -82,6 +84,12 @@ bool AreaContainsPoint(const std::vector<common::Coordinate>& area,
    return areaContainsPoint;
 }
 
+
+
+
+
+
+
 units::angle::degrees<double>
 GetAngle(double lat1, double lon1, double lat2, double lon2)
 {
@@ -137,6 +145,93 @@ GetDistance(double lat1, double lon1, double lat2, double lon2)
    return units::length::meters<double> {distance};
 }
 
+bool AreaInRangeOfPoint(const std::vector<common::Coordinate>& area,
+                        const common::Coordinate&              point,
+                        const units::length::meters<double>    distance)
+{
+   // Cannot have an area with just two points
+   if (area.size() <= 2 || (area.size() == 3 && area.front() == area.back()))
+   {
+      return false;
+   }
+
+
+
+   ::GeographicLib::Gnomonic      gnomonic =
+      ::GeographicLib::Gnomonic(DefaultGeodesic());
+   geos::geom::CoordinateSequence sequence {};
+   double                         x;
+   double                         y;
+
+   // Using a gnomonic projection with the test point as the center
+   // latitude/longitude, the projected test point will be at (0, 0)
+   geos::geom::CoordinateXY zero {};
+
+   // Create the area coordinate sequence using a gnomonic projection
+   for (auto& areaCoordinate : area)
+   {
+      gnomonic.Forward(point.latitude_,
+                       point.longitude_,
+                       areaCoordinate.latitude_,
+                       areaCoordinate.longitude_,
+                       x,
+                       y);
+      sequence.add(x, y);
+   }
+
+   // get a point on the circle with the radius of the range in lat lon.
+   units::angle::degrees<double> angle = units::angle::degrees<double>(0);
+   common::Coordinate radiusPoint = GetCoordinate(point, angle, distance);
+   // get the radius in gnomonic projection
+   gnomonic.Forward(point.latitude_,
+                    point.longitude_,
+                    radiusPoint.latitude_,
+                    radiusPoint.longitude_,
+                    x,
+                    y);
+   double gnomonicRadius = sqrt(x * x + y * y);
+
+   // If the sequence is not a ring, add the first point again for closure
+   if (!sequence.isRing())
+   {
+      sequence.add(sequence.front(), false);
+   }
+
+   // The sequence should be a ring at this point, but make sure
+   if (sequence.isRing())
+   {
+      try
+      {
+         if (geos::algorithm::PointLocation::isInRing(zero, &sequence))
+         {
+            return true;
+         }
+
+         // Calculate the distance the point is from the output
+         geos::algorithm::distance::PointPairDistance distancePair;
+         auto geometryFactory =
+            geos::geom::GeometryFactory::getDefaultInstance();
+         auto linearRing = geometryFactory->createLinearRing(sequence);
+         auto polygon    =
+            geometryFactory->createPolygon(std::move(linearRing));
+         geos::algorithm::distance::DistanceToPoint::computeDistance(*polygon,
+                                                                     zero,
+                                                                     distancePair);
+         if (gnomonicRadius > distancePair.getDistance())
+         {
+            return true;
+         }
+
+      }
+      catch (const std::exception&)
+      {
+         logger_->trace("Invalid area sequence");
+      }
+   }
+
+   return false;
+}
+
 } // namespace GeographicLib
 } // namespace util
 } // namespace qt

scwx-qt/source/scwx/qt/util/geographic_lib.hpp

@@ -90,6 +90,23 @@ common::Coordinate GetCoordinate(const common::Coordinate& center,
 units::length::meters<double>
 GetDistance(double lat1, double lon1, double lat2, double lon2);
 
+
+/**
+ * Determine if an area/ring, oriented in either direction, is within a
+ * distance of a point. A point lying on the area boundary is considered to be
+ * inside the area, and thus always in range. Any part of the area being inside
+ * the radius counts as inside.
+ *
+ * @param [in] area A vector of Coordinates representing the area
+ * @param [in] point The point to check against the area
+ * @param [in] distance The max distance in meters
+ *
+ * @return true if area is inside the radius of the point
+ */
+bool AreaInRangeOfPoint(const std::vector<common::Coordinate>& area,
+                        const common::Coordinate&              point,
+                        const units::length::meters<double>    distance);
+
 } // namespace GeographicLib
 } // namespace util
 } // namespace qt