Add helper function to determine the distance between two points

And use this to find a dive site within a certain radius of a GPS fix.
This will be used to figure out if dive sites might be the same.

This uses a new Qt5 component (Positioning) which was added in Qt5.2.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

5 files changed, 36 insertions, 2 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index c5e039185..f82ad3714 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -128,8 +128,8 @@ if(NOT (insource OR insourcedir))
 endif()
 
 # configure Qt.
-find_package(Qt5 REQUIRED COMPONENTS Core Concurrent Widgets Network WebKitWidgets PrintSupport Svg Test LinguistTools)
-set(QT_LIBRARIES Qt5::Core Qt5::Concurrent Qt5::Widgets Qt5::Network Qt5::WebKitWidgets Qt5::PrintSupport Qt5::Svg)
+find_package(Qt5 REQUIRED COMPONENTS Core Concurrent Widgets Network WebKitWidgets PrintSupport Svg Test LinguistTools Positioning)
+set(QT_LIBRARIES Qt5::Core Qt5::Concurrent Qt5::Widgets Qt5::Network Qt5::WebKitWidgets Qt5::PrintSupport Qt5::Svg Qt5::Positioning)
 set(QT_TEST_LIBRARIES ${QT_LIBRARIES} Qt5::Test)
 
 # Generate the ssrf-config.h every 'make'
diff --git a/divesite.c b/divesite.c
index fbf01bf77..3caa7b3ba 100644
--- a/divesite.c
+++ b/divesite.c
@@ -34,6 +34,28 @@ uint32_t get_dive_site_uuid_by_gps(degrees_t latitude, degrees_t longitude, stru
 	return 0;
 }
 
+/* this is in globe.cpp, so including the .h file is a pain */
+extern double getDistance(int lat1, int lon1, int lat2, int lon2);
+
+/* find the closest one, no more than distance meters away - if more than one at same distance, pick the first */
+uint32_t get_dive_site_uuid_by_gps_proximity(degrees_t latitude, degrees_t longitude, int distance, struct dive_site **dsp)
+{
+	int i;
+	int uuid = 0;
+	struct dive_site *ds;
+	double cur_distance, min_distance = distance + 0.001;
+	for_each_dive_site (i, ds) {
+		if (dive_site_has_gps_location(ds) &&
+		    (cur_distance = getDistance(ds->latitude.udeg, ds->longitude.udeg, latitude.udeg, longitude.udeg)) < min_distance) {
+			min_distance = cur_distance;
+			uuid = ds->uuid;
+			if (dsp)
+				*dsp = ds;
+		}
+	}
+	return uuid;
+}
+
 /* try to create a uniqe ID - fingers crossed */
 static uint32_t dive_site_getUniqId()
 {
diff --git a/divesite.h b/divesite.h
index ca650259a..79adf664a 100644
--- a/divesite.h
+++ b/divesite.h
@@ -53,6 +53,7 @@ uint32_t create_dive_site(const char *name);
 uint32_t create_dive_site_with_gps(const char *name, degrees_t latitude, degrees_t longitude);
 uint32_t get_dive_site_uuid_by_name(const char *name, struct dive_site **dsp);
 uint32_t get_dive_site_uuid_by_gps(degrees_t latitude, degrees_t longitude, struct dive_site **dsp);
+uint32_t get_dive_site_uuid_by_gps_proximity(degrees_t latitude, degrees_t longitude, int distance, struct dive_site **dsp);
 bool dive_site_is_empty(struct dive_site *ds);
 
 #ifdef __cplusplus
diff --git a/qt-ui/globe.cpp b/qt-ui/globe.cpp
index b8e0ec87e..76d48b7ba 100644
--- a/qt-ui/globe.cpp
+++ b/qt-ui/globe.cpp
@@ -1,4 +1,5 @@
 #include "globe.h"
+#include <QGeoCoordinate>
 #ifndef NO_MARBLE
 #include "mainwindow.h"
 #include "helpers.h"
@@ -392,3 +393,10 @@ void GlobeGPS::reload()
 {
 }
 #endif
+
+extern "C" double getDistance(int lat1, int lon1, int lat2, int lon2)
+{
+	QGeoCoordinate c1(lat1 / 1000000.0, lon1 / 1000000.0);
+	QGeoCoordinate c2(lat2 / 1000000.0, lon2 / 1000000.0);
+	return c1.distanceTo(c2);
+}
diff --git a/qt-ui/globe.h b/qt-ui/globe.h
index 903b9f89c..1791e0ff3 100644
--- a/qt-ui/globe.h
+++ b/qt-ui/globe.h
@@ -74,4 +74,7 @@ slots:
 };
 
 #endif // NO_MARBLE
+
+extern "C" double getDistance(int lat1, int lon1, int lat2, int lon2);
+
 #endif // GLOBE_H