X-Git-Url: https://git.gag.com/?a=blobdiff_plain;f=altoslib%2FAltosMapTransform.java;h=ae78befaa2a3f9d7b1290e351c769fca8a8f7eb2;hb=d1af180c2d2a2caf1e13f00d83f2b86ba26de27f;hp=30994ecb60bc2dc826f50f6fffbc546b07882e24;hpb=3882e358b6f2970cb1afebcf2a71da34a57002df;p=fw%2Faltos diff --git a/altoslib/AltosMapTransform.java b/altoslib/AltosMapTransform.java index 30994ecb..ae78befa 100644 --- a/altoslib/AltosMapTransform.java +++ b/altoslib/AltosMapTransform.java @@ -15,7 +15,7 @@ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ -package org.altusmetrum.altoslib_7; +package org.altusmetrum.altoslib_9; import java.io.*; import java.lang.Math; @@ -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; + } }