Added GPX exporter

css/main.css

@@ -1224,7 +1224,8 @@ html:not(.has-log) #status-bar {
 }
 
 html:not(.has-gps) .view-map,
-html:not(.has-gps) .map-container {
+html:not(.has-gps) .map-container,
+html:not(.has-gps) .btn-gpx-export {
 	display: none !important;
 }
 

index.html

@@ -186,6 +186,7 @@ <h1>Welcome to the Enhanced Blackbox Explorer!</h1>
                         <a class="btn btn-primary btn-workspaces-export" data-toggle="tooltip" title="Export your workspace configurations to file">
                             Export Workspaces...</a>
                         <a class="btn btn-primary btn-csv-export" data-toggle="tooltip" title="Export your current graphs to CSV file"> Export CSV...</a>
+                        <a class="btn btn-primary btn-gpx-export" data-toggle="tooltip" title="Export your flight to GPX file"> Export GPX...</a>
                         <span class="btn btn-primary btn-file" data-toggle="tooltip" title="Open another log file, video file, exported workspace file or configuration dump file">
                             Open log file/video
                             <input type="file" class="file-open" accept=".bbl,.txt,.cfl,.bfl,.log,.avi,.mov,.mp4,.mpeg,.json" multiple />
@@ -3152,6 +3153,7 @@ <h4 class="modal-title">Advanced User Settings</h4>
     <script src="js/graph_spectrum.js"></script>
     <script src="js/sticks.js"></script>
     <script src="js/csv-exporter.js"></script>
+    <script src="js/gpx-exporter.js"></script>
     <script src="js/gui.js"></script>
     <script src="js/header_dialog.js"></script>
     <script src="js/keys_dialog.js"></script>

js/csv-exporter.js

@@ -44,4 +44,4 @@ let CsvExporter = function(flightLog, opts={}) {
     return {
         dump: dump,
     };
-};
+};

js/gpx-exporter.js

@@ -0,0 +1,32 @@
+"use strict";
+
+/**
+ * @constructor
+ * @param {FlightLog} flightLog 
+ */
+let GpxExporter = function(flightLog) {
+
+    /** 
+     * @param {function} success is a callback triggered when export is done
+     */
+    function dump(success) {
+        let frames = _(flightLog.getChunksInTimeRange(flightLog.getMinTime(), flightLog.getMaxTime()))
+                .map(chunk => chunk.frames).value(),
+            worker = new Worker("/js/webworkers/gpx-export-worker.js");
+
+        worker.onmessage = event => {
+            success(event.data);
+            worker.terminate();
+        };
+        worker.postMessage({
+            sysConfig: flightLog.getSysConfig(),
+            fieldNames: flightLog.getMainFieldNames(),
+            frames: frames,
+        });
+    }
+
+    // exposed functions
+    return {
+        dump: dump,
+    };
+};

js/main.js

@@ -111,12 +111,12 @@ function BlackboxLogViewer() {
         animationFrameIsQueued = false,
 
         playbackRate = PLAYBACK_DEFAULT_RATE,
-        
+
         graphZoom = GRAPH_DEFAULT_ZOOM,
         lastGraphZoom = GRAPH_DEFAULT_ZOOM, // QuickZoom function.
-        
+
         mapGrapher = new MapGrapher();
-        
+
 
         function createNewBlackboxWindow(fileToOpen) {
 
@@ -309,7 +309,7 @@ function BlackboxLogViewer() {
             if(flightLog.hasGpsData()) {
                 mapGrapher.resize(width, height);
             }
-            
+
             invalidateGraph();
         }
     }
@@ -918,28 +918,35 @@ function BlackboxLogViewer() {
         reader.readAsText(file);
     }
 
-    function exportCsv(file, options={}) {
-
-        function onSuccess(data) {
-            console.debug("CSV export finished in", (performance.now() - startTime) / 1000, "secs");
+    function createExportCallback(fileExtension, fileType, file, startTime) {
+        const callback = function(data) {
+            console.debug(`${fileExtension.toUpperCase()} export finished in ${(performance.now() - startTime) / 1000} secs`);
             if (!data) {
                 console.debug("Empty data, nothing to save");
                 return;
             }
-            let blob = new Blob([data], {type: 'text/csv'}),
+            let blob = new Blob([data], {type: fileType}),
                 e    = document.createEvent('MouseEvents'),
                 a    = document.createElement('a');
-            a.download = file || $(".log-filename").text() + ".csv";
+            a.download = file || $(".log-filename").text() + "." + fileExtension;
             a.href = window.URL.createObjectURL(blob);
-            a.dataset.downloadurl =  ['text/csv', a.download, a.href].join(':');
+            a.dataset.downloadurl =  [fileType, a.download, a.href].join(':');
             e.initMouseEvent('click', true, false, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
             a.dispatchEvent(e);
-        }
+          };
+          return callback;
+    }
 
-        let startTime = performance.now();
+    function exportCsv(file, options={}) {
+        const onSuccess = createExportCallback('csv', 'text/csv', file, performance.now());
         CsvExporter(flightLog, options).dump(onSuccess);
     }
 
+    function exportGpx(file) {
+        const onSuccess = createExportCallback('gpx', 'GPX File', file, performance.now());
+        GpxExporter(flightLog).dump(onSuccess);
+    }
+
     function newGraphConfig(newConfig) {
         lastGraphConfig = graphConfig; // Remember the last configuration.
         graphConfig = newConfig;
@@ -1129,7 +1136,7 @@ function BlackboxLogViewer() {
 
         $(".view-map").click(function() {
             hasMap = !hasMap;
-            html.toggleClass("has-map", hasMap);       
+            html.toggleClass("has-map", hasMap);
             prefs.set('hasMap', hasMap);
             if(flightLog.hasGpsData()) {
                 mapGrapher.initialize(userSettings);
@@ -1470,6 +1477,11 @@ function BlackboxLogViewer() {
             exportCsv();
             e.preventDefault();
         });
+        $(".btn-gpx-export").click(function(e) {
+            setGraphState(GRAPH_STATE_PAUSED);
+            exportGpx();
+            e.preventDefault();
+        });
 
         if (FlightLogVideoRenderer.isSupported()) {
             $(".btn-video-export").click(function(e) {

js/webworkers/csv-export-worker.js

@@ -42,4 +42,4 @@ onmessage = function(event) {
 
     postMessage(result);
 
-};
+};

js/webworkers/gpx-export-worker.js

@@ -0,0 +1,52 @@
+importScripts("/node_modules/lodash/lodash.min.js");
+
+onmessage = function (event) {
+  const header = `<?xml version="1.0" encoding="UTF-8"?>
+<gpx xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.topografix.com/GPX/1/1" xsi:schemaLocation="http://www.topografix.com/GPX/1/1 http://www.topografix.com/GPX/1/1/gpx.xsd http://www.topografix.com/GPX/gpx_style/0/2 http://www.topografix.com/GPX/gpx_style/0/2/gpx_style.xsd" xmlns:gpx_style="http://www.topografix.com/GPX/gpx_style/0/2" 
+  version="1.1" 
+  creator="https://github.com/betaflight/blackbox-log-viewer">
+  <metadata>
+    <author>
+      <name>Betaflight Blackbox Explorer</name>
+      <link href="https://github.com/betaflight/blackbox-log-viewer"></link>
+    </author>
+  </metadata>`;
+
+  const footer = `</gpx>`;
+
+  const timeIndex = event.data.fieldNames.indexOf("time");
+  const latIndex = event.data.fieldNames.indexOf("GPS_coord[0]");
+  const lngIndex = event.data.fieldNames.indexOf("GPS_coord[1]");
+  const altitudeIndex = event.data.fieldNames.indexOf("GPS_altitude");
+
+  let trkpts = "";
+  for (const chunk of event.data.frames) {
+    for (const frame of chunk) {
+      if (!frame[latIndex] || !frame[lngIndex]) {
+        continue;
+      }
+      const timeMillis = Math.floor(frame[timeIndex] / 1000);
+      const lat = frame[latIndex] / 10000000;
+      const lng = frame[lngIndex] / 10000000;
+      const altitude = frame[altitudeIndex] / 10;
+
+      let date = new Date(event.data.sysConfig["Log start datetime"]);
+      date.setTime(date.getTime() + timeMillis);
+
+      let trkpt = `<trkpt lat="${lat}" lon="${lng}">`;
+      trkpt += `<ele>${altitude}</ele>`;
+      trkpt += `<time>${date.toISOString()}</time>`;
+      trkpt += `</trkpt>\n`;
+
+      trkpts += trkpt;
+    }
+  }
+
+  let trk = `  <trk>
+    <trkseg>
+      ${trkpts}
+    </trkseg>
+  </trk>`;
+
+  postMessage(header + "\n" + trk + "\n" + footer);
+};