From ab02efd4224aa4b15e99139a189dfbff91524dee Mon Sep 17 00:00:00 2001
From: parkrrrr <parkrrrr@f51c46e8-681c-474f-0cfe-069cfd0219fb>
Date: Wed, 17 Mar 2004 15:24:30 +0000
Subject: [PATCH] (1) Points that coincide with a polygon vertex are now inside
 the polygon by fiat. (2) Fixed bug in intersection detector when test point
 was inside segment bbox

---
 gpsbabel/polygon.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/gpsbabel/polygon.c b/gpsbabel/polygon.c
index da35b7683..3835f7de0 100644
--- a/gpsbabel/polygon.c
+++ b/gpsbabel/polygon.c
@@ -38,6 +38,7 @@ static char *exclopt = NULL;
 
 typedef struct {
 	unsigned short state;
+	unsigned short override;
 } extra_data;
 
 static
@@ -163,7 +164,7 @@ static void polytest ( double lat1, double lon1,
 		}
 		else if (!(lon1 <= lon3 && lon2 <= lon3)) {
 		    /* we're inside the bbox of a diagonal line.  math time. */
-		    double loni = (lon2-lon1)/(lat2-lat1)*(lat3-lat1);
+		    double loni = lon1+(lon2-lon1)/(lat2-lat1)*(lat3-lat1);
 		    if ( loni > lon3 ) {
 		        *state = *state ^ INSIDE;
 		    }
@@ -221,8 +222,13 @@ polygon_process(void)
 		else {
 		    ed = xcalloc(1, sizeof(*ed));
 		    ed->state = OUTSIDE;
+		    ed->override = 0;
 		    waypointp->extra_data = ed;
 		}
+		if ( lat2 == waypointp->latitude && 
+		     lon2 == waypointp->longitude ) {
+		    ed->override = 1;
+		}
 	        if ( olat != BADVAL && olon != BADVAL &&
 	            olat == lat2 && olon == lon2 ) {
 		    last = 1;
@@ -263,6 +269,7 @@ polygon_process(void)
 		ed = wp->extra_data;
 		wp->extra_data = NULL;
 	        if ( ed ) {
+		    if ( ed->override ) ed->state = INSIDE;
 		    if (((ed->state & INSIDE) == OUTSIDE ) == (exclopt == NULL)) {
 			waypt_del(wp);
 			waypt_free(wp);
-- 
2.30.2