X-Git-Url: https://git-public.kairo.at/?p=lantea.git;a=blobdiff_plain;f=js%2Fmap.js;h=f9ce632f83c9ecdb2d497bc159b16025a52d0177;hp=ff5112a6ed0d02e63397db6a259c1db55e846e87;hb=7a076538678eb75b90e066df5e2d51346067927d;hpb=64dac5e1fc28b6084393c7e413b271c10cf21cfb

diff --git a/js/map.js b/js/map.js
index ff5112a..f9ce632 100644
--- a/js/map.js
+++ b/js/map.js
@@ -129,6 +129,8 @@ function loadPrefs(aEvent) {
 
       document.getElementById("body").addEventListener("keydown", mapEvHandler, false);
 
+      document.addEventListener("visibilitychange", visibilityEvHandler, false);
+
       console.log("Events added.");
       document.getElementById("copyright").innerHTML =
           gMapStyles[gMap.activeMap].copyright;
@@ -185,11 +187,14 @@ function loadPrefs(aEvent) {
       if (aTPoint) {
         // Add in front and return new length.
         var tracklen = gTrack.unshift(aTPoint);
-        // Redraw track periodically, larger distance the longer it gets.
+        // Redraw track periodically, larger distance the longer it gets
+        // (but clamped to the first value over a certain limit).
         // Initial paint will do initial track drawing.
         if (tracklen % redrawBase == 0) {
           drawTrack();
-          redrawBase = tracklen;
+          if (redrawBase < 1000) {
+            redrawBase = tracklen;
+          }
         }
       }
       else {
@@ -377,7 +382,9 @@ var gMap = {
               var imgObj = new Image();
               imgObj.onload = function() {
                 gMap.loadImageToTexture(imgObj, aTileKey);
-                window.requestAnimationFrame(function(aTimestamp) { gMap.drawGL() });
+                if (document.hidden != true) { // Only draw if we're actually visible.
+                  window.requestAnimationFrame(function(aTimestamp) { gMap.drawGL() });
+                }
                 URL.revokeObjectURL(imgURL);
               }
               imgObj.src = imgURL;
@@ -386,7 +393,9 @@ var gMap = {
         }
       }
     }
-    window.requestAnimationFrame(function(aTimestamp) { gMap.drawGL() });
+    if (document.hidden != true) { // Only draw if we're actually visible.
+      window.requestAnimationFrame(function(aTimestamp) { gMap.drawGL() });
+    }
   },
 
   drawGL: function() {
@@ -645,13 +654,15 @@ function decodeIndex(encodedIdx) {
 }
 
 function drawTrack() {
-  gLastDrawnPoint = null;
-  gCurPosMapCache = undefined;
-  gTrackContext.clearRect(0, 0, gTrackCanvas.width, gTrackCanvas.height);
-  if (gTrack.length) {
-    for (var i = 0; i < gTrack.length; i++) {
-      drawTrackPoint(gTrack[i].coords.latitude, gTrack[i].coords.longitude,
-                     (i + 1 >= gTrack.length));
+  if (gTrackContext && (document.hidden != true)) { // Only draw if we're actually visible.
+    gLastDrawnPoint = null;
+    gCurPosMapCache = undefined;
+    gTrackContext.clearRect(0, 0, gTrackCanvas.width, gTrackCanvas.height);
+    if (gTrack.length) {
+      for (var i = 0; i < gTrack.length; i++) {
+        drawTrackPoint(gTrack[i].coords.latitude, gTrack[i].coords.longitude,
+                      (i + 1 >= gTrack.length));
+      }
     }
   }
 }
@@ -729,6 +740,50 @@ function undrawCurrentLocation() {
   }
 }
 
+function calcTrackDuration() {
+  // Get the duration of the track in s.
+  var tDuration = 0;
+  if (gTrack.length > 1) {
+    for (var i = 1; i < gTrack.length; i++) {
+      tDuration += (gTrack[i].time - gTrack[i-1].time);
+    }
+  }
+  return Math.round(tDuration / 1000); // The timestamps are in ms but we return seconds.
+}
+
+function calcTrackLength() {
+  // Get the length of the track in km.
+  var tLength = 0;
+  if (gTrack.length > 1) {
+    for (var i = 1; i < gTrack.length; i++) {
+      tLength += getPointDistance(gTrack[i-1].coords, gTrack[i].coords);
+    }
+  }
+  return tLength;
+}
+
+function getPointDistance(aGPSPoint1, aGPSPoint2) {
+  // Get the distance in km between the two given GPS points.
+  // See http://stackoverflow.com/questions/365826/calculate-distance-between-2-gps-coordinates
+  // Earth is almost exactly a sphere and we calculate small distances on the surface, so we can do spherical great-circle math.
+  // Also see http://en.wikipedia.org/wiki/Great-circle_distance
+  var R = 6371; // km
+  var dLat = deg2rad(aGPSPoint2.latitude - aGPSPoint1.latitude);
+  var dLon = deg2rad(aGPSPoint2.longitude - aGPSPoint1.longitude);
+  var lat1 = deg2rad(aGPSPoint1.latitude);
+  var lat2 = deg2rad(aGPSPoint2.latitude);
+
+  var a = Math.sin(dLat/2) * Math.sin(dLat/2) +
+          Math.sin(dLon/2) * Math.sin(dLon/2) * Math.cos(lat1) * Math.cos(lat2);
+  var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
+  return R * c;
+}
+
+function deg2rad(aDegreeValue) {
+  // Convert an angle in degrees to radiants.
+  return aDegreeValue * (Math.PI / 180);
+}
+
 var mapEvHandler = {
   handleEvent: function(aEvent) {
     var touchEvent = aEvent.type.indexOf('touch') != -1;
@@ -960,6 +1015,15 @@ var mapEvHandler = {
   }
 };
 
+function visibilityEvHandler() {
+  // Immediately draw if we just got visible.
+  if (document.hidden != true) {
+    gMap.draw();
+  }
+  // No need to handle the event where we become invisible as we care only draw
+  // when we are visible anyhow.
+}
+
 var geofake = {
   tracking: false,
   lastPos: {x: undefined, y: undefined},
@@ -1103,8 +1167,8 @@ var gTileService = {
                   .replace("{x}", norm.x)
                   .replace("{y}", norm.y)
                   .replace("{z}", norm.z)
-                  .replace("[a-c]", String.fromCharCode(97 + Math.floor(Math.random() * 2)))
-                  .replace("[1-4]", 1 + Math.floor(Math.random() * 3)),
+                  .replace("[a-c]", String.fromCharCode(97 + Math.floor(Math.random() * 3)))
+                  .replace("[1-4]", 1 + Math.floor(Math.random() * 4)),
                 true);
       XHR.responseType = "blob";
       XHR.addEventListener("load", function () {