X-Git-Url: https://git.gag.com/?a=blobdiff_plain;f=altoslib%2FAltosMapTransform.java;h=7615c83b3f530b79f3189c8ac34552e584aa8e38;hb=2997c9720f58b2955925e4e99c11a6ec302114a9;hp=30994ecb60bc2dc826f50f6fffbc546b07882e24;hpb=3882e358b6f2970cb1afebcf2a71da34a57002df;p=fw%2Faltos

diff --git a/altoslib/AltosMapTransform.java b/altoslib/AltosMapTransform.java
index 30994ecb..7615c83b 100644
--- a/altoslib/AltosMapTransform.java
+++ b/altoslib/AltosMapTransform.java
@@ -51,6 +51,13 @@ public class AltosMapTransform {
 		return new AltosPointDouble(screen.x + offset_x, screen.y + offset_y);
 	}
 
+	public double hypot(AltosLatLon a, AltosLatLon b) {
+		AltosPointDouble	a_pt = point(a);
+		AltosPointDouble	b_pt = point(b);
+
+		return Math.hypot(a_pt.x - b_pt.x, a_pt.y - b_pt.y);
+	}
+
 	public AltosLatLon screen_lat_lon(AltosPointInt screen) {
 		return lat_lon(screen_point(screen));
 	}
@@ -110,4 +117,12 @@ public class AltosMapTransform {
 		offset_x = centre_pt.x - width / 2.0;
 		offset_y = centre_pt.y - height / 2.0;
 	}
+
+	public static double lon_from_distance(double lat, double distance) {
+		double c = AltosGreatCircle.earth_radius * Math.cos(lat * Math.PI / 180) * 2 * Math.PI;
+
+		if (c < 10)
+			return 0;
+		return distance/c * 360.0;
+	}
 }