From 8db66fa81bbfab66a497c8bc3fd1716d0bf9f563 Mon Sep 17 00:00:00 2001
From: robertl <robertl@f51c46e8-681c-474f-0cfe-069cfd0219fb>
Date: Mon, 28 Apr 2003 13:45:04 +0000
Subject: [PATCH] Add position filter for radius, courtesy Alex Mottram.

---
 gpsbabel/README        | 17 +++++++++
 gpsbabel/filter_vecs.c |  6 ++++
 gpsbabel/position.c    | 79 ++++++++++++++++++++++++++++++++++++++++--
 gpsbabel/testo         |  9 +++++
 4 files changed, 108 insertions(+), 3 deletions(-)

diff --git a/gpsbabel/README b/gpsbabel/README
index 0db94a679..a5e64c4a1 100644
--- a/gpsbabel/README
+++ b/gpsbabel/README
@@ -336,6 +336,23 @@ DATA FILTERS
 	leaving just one.
 
 
+    RADIUS
+
+	The radius filter is designed to include points based on their
+	proximity to a central point.  Distances and the central point 
+	are declared on the command line by passing the distance=X.XX,
+	lat=X.XX, and lon=X.XX options to the filter.  Distance options 
+	may be expressed in miles (distance=3M) or kilometers (distance=3K).
+	The default is zero miles.
+
+	For example:
+
+	gpsbabel -i geo -f 1.loc -x radius,distance=1.5M,lat=30.0,lon=-90.0 \
+	         -o mapsend -F 2.wpt
+
+	would include only points within 1.5 miles of N30.000 W90.000 
+
+
     DUPLICATE
 
 	The duplicate filter is designed to remove duplicate points based
diff --git a/gpsbabel/filter_vecs.c b/gpsbabel/filter_vecs.c
index 4dc76b0de..3f87a8700 100644
--- a/gpsbabel/filter_vecs.c
+++ b/gpsbabel/filter_vecs.c
@@ -29,6 +29,7 @@ typedef struct {
 } fl_vecs_t;
 
 extern filter_vecs_t position_vecs;
+extern filter_vecs_t radius_vecs;
 extern filter_vecs_t duplicate_vecs;
 
 static
@@ -38,6 +39,11 @@ fl_vecs_t filter_vec_list[] = {
 		"position",
 		"Remove Points Within Distance",
 	}, 
+	{
+		&radius_vecs, 
+		"radius",
+		"Include Only Points Within Radius",
+	}, 
 	{
 		&duplicate_vecs, 
 		"duplicate",
diff --git a/gpsbabel/position.c b/gpsbabel/position.c
index 36cceb54f..3c1b7a019 100644
--- a/gpsbabel/position.c
+++ b/gpsbabel/position.c
@@ -1,5 +1,5 @@
 /*
-    Distance Between Points Filter
+    Distance Between Points Filter(s)
 
     Copyright (C) 2002 Robert Lipe, robertlipe@usa.net
 
@@ -30,6 +30,10 @@ extern queue waypt_head;
 
 static double pos_dist;
 static char *distopt;
+static char *latopt;
+static char *lonopt;
+
+waypoint * home_pos;
 
 static
 arglist_t position_args[] = {
@@ -37,6 +41,14 @@ arglist_t position_args[] = {
 	{0, 0, 0}
 };
 
+static
+arglist_t radius_args[] = {
+	{"lat", &latopt,       "Latitude for center point (D.DDDDD)"},
+	{"lon", &lonopt,       "Longitude for center point (D.DDDDD)"},
+	{"distance", &distopt, "Maximum distance from center"},
+	{0, 0, 0}
+};
+
 static double
 gc_distance(double lat1, double lon1, double lat2, double lon2)
 {
@@ -81,7 +93,7 @@ position_comp(const void * a, const void * b)
 	return(0);
 }
 
-void
+void 
 position_process(void)
 {
 	queue * elem, * tmp;
@@ -111,7 +123,7 @@ position_process(void)
 		/* convert radians to integer feet */
 		dist = (int)((((dist * 180.0 * 60.0) / M_PI) * 1.1516) * 5280.0);
 
-		if (dist <= pos_dist) { 
+		if (dist <= pos_dist) {
 			waypt_del(comp[i]);
 			waypt_free(comp[i]);
 		}
@@ -141,9 +153,70 @@ void
 position_deinit(void) {
 }
 
+void 
+radius_process(void)
+{
+	queue * elem, * tmp;
+	waypoint * waypointp;
+	double dist;
+
+	QUEUE_FOR_EACH(&waypt_head, elem, tmp) {
+		waypointp = (waypoint *)elem;
+
+		dist = gc_distance(waypointp->position.latitude.degrees,
+				   waypointp->position.longitude.degrees,
+				   home_pos->position.latitude.degrees,
+				   home_pos->position.longitude.degrees);
+
+		/* convert radians to float point statute miles */
+		dist = (((dist * 180.0 * 60.0) / M_PI) * 1.1516);
+
+		if (dist >= pos_dist) {
+			waypt_del(waypointp);
+			waypt_free(waypointp);
+		}
+	}
+}
+
+void
+radius_init(const char *args) {
+	char *fm;
+
+	pos_dist = 0;
+
+	if (distopt) {
+		pos_dist = strtod(distopt, &fm);
+
+		if ((*fm == 'k') || (*fm == 'K')) {
+			 /* distance is kilometers, convert to feet */
+			pos_dist *= .6214;
+		}
+	}
+
+	home_pos = xcalloc(sizeof(*home_pos), 1);
+
+	if (latopt)
+		home_pos->position.latitude.degrees = atof(latopt);
+	if (lonopt)
+		home_pos->position.longitude.degrees = atof(lonopt);
+}
+
+void
+radius_deinit(void) {
+	if (home_pos)
+		xfree(home_pos);
+}
+
 filter_vecs_t position_vecs = {
 	position_init,
 	position_process,
 	position_deinit,
 	position_args
 };
+
+filter_vecs_t radius_vecs = {
+	radius_init,
+	radius_process,
+	radius_deinit,
+	radius_args
+};
diff --git a/gpsbabel/testo b/gpsbabel/testo
index 2ff9ba643..4c218bb8f 100755
--- a/gpsbabel/testo
+++ b/gpsbabel/testo
@@ -239,6 +239,15 @@ ${PNAME} -i geo -f geocaching.loc -f geocaching.loc -x position,distance=5f \
 		-o csv -F ${TMPDIR}/filterpos.csv2
 compare ${TMPDIR}/filterpos.csv1 ${TMPDIR}/filterpos.csv2
 
+#
+# Radius filter
+#
+rm -f ${TMPDIR}/radius.csv
+${PNAME} -i geo -f geocaching.loc \
+		-x radius,lat=35.9720,lon=-87.1347,distance=14.7 \
+		-o csv -F ${TMPDIR}/radius.csv
+compare ${TMPDIR}/radius.csv reference/
+
 #
 # magellan SD card waypoint / route format
 #
-- 
2.30.2