Add ordnance survey app

apps.json

@@ -2088,5 +2088,17 @@
         "url": "settings.js"
       }
     ]
+  },
+  { "id": "osgridref",
+    "name": "Ordnance Survey Grid Reference",
+    "shortName":"OS Grid ref",
+    "icon": "app.png",
+    "version":"0.01",
+    "description": "Displays the UK Ordnance Survey grid reference of your current GPS location. Useful when in the United Kingdom with an Ordnance Survey map",
+    "tags": "outdoors,gps",
+    "storage": [
+      {"name":"osgridref.app.js","url":"app.js"},
+      {"name":"osgridref.img","url":"app-icon.js","evaluate":true}
+    ]
   }
 ]

apps/osgridref/ChangeLog

@@ -0,0 +1 @@
+0.01: New App!

apps/osgridref/app-icon.js

@@ -0,0 +1 @@
+require("heatshrink").decompress(atob("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"))

apps/osgridref/app.js

@@ -0,0 +1,89 @@
+function getLogo() {
+  return require("heatshrink").decompress(atob("mUcggHE1QADCY3L3cA5gCBAAoXEDI0M3YVChe8BYmgDAwZE4AYDAAOwAYUKDAMKC4mgBgUL2AYFAgYQBDA4yC3e8MYRhIhQYFAoJ6DhYYHCoQRCDApMC3fA5gwHDAxqBG4R7BGQJ3DDA8KGIY7BAYUMO4pJDDAgXDQQYYBhmw5bgBDBY6EMgMLPYIxBQAPADAimDDYIhDPogYC3hOCLwT5D0ASCDAhIBcobMCCgYRDVwg6ChnLMIPA3cMDAgqEfIgxCCIIzB2BLBToIYMKAW7JYSYC4GwH4YYGJYJfCLoLHFDAIVBMY5hCSowWBgG8BYI/CCoY5EFYcLDAIXBPoYaCAgTNBAQQYEGgfMhYxBOIYwEJoRkDM4vLDAYJBDAj4FJghLBcIRYCCQRhCPogAEMAO8fgIuCDAg2EDAz5BS4YWBCQZgDJIUMB4TDCDAJiBAAT1FZwQLCCAm8DAIgEGIZNFDI27hhTGDIQYCPA28FgIvBGAQ"));
+}
+
+g.clear(1);
+g.drawImage(getLogo(),g.getWidth()-50, g.getHeight()-(28+24));
+Bangle.loadWidgets();
+Bangle.drawWidgets();
+
+function onGPS(fix) {
+  var os = {northing:"---", easting:"---"}
+  var state = "";
+  if (fix.fix) {
+    os = OsGridRef.latLongToOsGrid(fix);
+    state = "GPS Fix";
+  } else {
+    state = "No Fix ";
+  }
+  var y = 30, h=48, d1 = 18, d2 = 80;
+  g.reset();
+  g.setFont("6x8",2).setFontAlign(-1,-1);
+  g.drawString("Northing", 10,y);
+  g.drawString("Easting", 10,y+d2);
+  g.drawString(state,10,g.getHeight()-48,true/*erase bg*/)
+  g.setFont("6x8",1);
+  g.drawString(fix.satellites+" Satellites ",10,g.getHeight()-32,true/*erase bg*/)
+  g.setFont("Vector",h).setFontAlign(1,-1);
+  g.clearRect(0,y+d1,g.getWidth()-1,y+d1+h);
+  g.drawString(os.northing, g.getWidth()-1,y+d1);
+  g.clearRect(0,y+d1+d2,g.getWidth()-1,y+d1+d2+h);
+  g.drawString(os.easting, g.getWidth()-1,y+d1+d2);
+}
+
+Bangle.setGPSPower(1);
+Bangle.on('GPS', onGPS);
+
+Number.prototype.toRad = function() { return this*Math.PI/180; };
+/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -  */
+/*  Ordnance Survey Grid Reference functions  (c) Chris Veness 2005-2014                          */
+/*   - www.movable-type.co.uk/scripts/gridref.js                                                  */
+/*   - www.movable-type.co.uk/scripts/latlon-gridref.html                                         */
+/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -  */
+function OsGridRef(easting, northing) {
+  this.easting = 0|easting;
+  this.northing = 0|northing;
+}
+OsGridRef.latLongToOsGrid = function(point) {
+  var lat = point.lat.toRad();
+  var lon = point.lon.toRad();
+
+  var a = 6377563.396, b = 6356256.909;          // Airy 1830 major & minor semi-axes
+  var F0 = 0.9996012717;                         // NatGrid scale factor on central meridian
+  var lat0 = (49).toRad(), lon0 = (-2).toRad();  // NatGrid true origin is 49<34>N,2<>W
+  var N0 = -100000, E0 = 400000;                 // northing & easting of true origin, metres
+  var e2 = 1 - (b*b)/(a*a);                      // eccentricity squared
+  var n = (a-b)/(a+b), n2 = n*n, n3 = n*n*n;
+
+  var cosLat = Math.cos(lat), sinLat = Math.sin(lat);
+  var nu = a*F0/Math.sqrt(1-e2*sinLat*sinLat);              // transverse radius of curvature
+  var rho = a*F0*(1-e2)/Math.pow(1-e2*sinLat*sinLat, 1.5);  // meridional radius of curvature
+  var eta2 = nu/rho-1;
+
+  var Ma = (1 + n + (5/4)*n2 + (5/4)*n3) * (lat-lat0);
+  var Mb = (3*n + 3*n*n + (21/8)*n3) * Math.sin(lat-lat0) * Math.cos(lat+lat0);
+  var Mc = ((15/8)*n2 + (15/8)*n3) * Math.sin(2*(lat-lat0)) * Math.cos(2*(lat+lat0));
+  var Md = (35/24)*n3 * Math.sin(3*(lat-lat0)) * Math.cos(3*(lat+lat0));
+  var M = b * F0 * (Ma - Mb + Mc - Md);              // meridional arc
+
+  var cos3lat = cosLat*cosLat*cosLat;
+  var cos5lat = cos3lat*cosLat*cosLat;
+  var tan2lat = Math.tan(lat)*Math.tan(lat);
+  var tan4lat = tan2lat*tan2lat;
+
+  var I = M + N0;
+  var II = (nu/2)*sinLat*cosLat;
+  var III = (nu/24)*sinLat*cos3lat*(5-tan2lat+9*eta2);
+  var IIIA = (nu/720)*sinLat*cos5lat*(61-58*tan2lat+tan4lat);
+  var IV = nu*cosLat;
+  var V = (nu/6)*cos3lat*(nu/rho-tan2lat);
+  var VI = (nu/120) * cos5lat * (5 - 18*tan2lat + tan4lat + 14*eta2 - 58*tan2lat*eta2);
+
+  var dLon = lon-lon0;
+  var dLon2 = dLon*dLon, dLon3 = dLon2*dLon, dLon4 = dLon3*dLon, dLon5 = dLon4*dLon, dLon6 = dLon5*dLon;
+
+  var N = I + II*dLon2 + III*dLon4 + IIIA*dLon6;
+  var E = E0 + IV*dLon + V*dLon3 + VI*dLon5;
+
+  return new OsGridRef(E, N);
+};