Add a track feature.

The track feature is a set of lines each of which is composed of points
with position and strictly monotonically increasing time.  There are
utility functions for setting a start and end time.  Two points are
interpolated along the track line: one each for the start and end times.
A marker or text value can be rendered at the end time.

Internally, the track is rendered as three line features; one for all
the points before the start time, one for the start to the end time, and
one for the end time onward.  Additional a marker and/or text feature is
used to render the track heads.

CHANGELOG.md

@@ -6,6 +6,7 @@
 - Added a marker feature (#1035)
 - The mapInteractor cancelOnMove option can now take a movement threshold (#1058)
 - GCS can now be specified in pointSearch, boxSearch, and polygonSearch (#1051)
+- Added a track feature (#1040)
 
 ## Version 0.19.8
 

examples/flights/main.js

@@ -73,7 +73,6 @@ function draw(drawData) {
     }
     feature.data(data);
   }
-  // feature.draw();
   map.scheduleAnimationFrame(feature.draw);
 }
 
@@ -115,12 +114,12 @@ feature = layer.createFeature('line', {selectionAPI: canSelect})
   .style({
     strokeColor: function (d, i, l) {
       if (!hasScale) {
-        // d3 scales are slow
+        // d3 scales are slow; don't do:
         // return d3Scale(0);
         return scale[0];
       }
       var val = (l.v[i] - ranges.v.min) / ranges.v.range;
-      // d3 scales are slow
+      // d3 scales are slow, don't do:
       // return d3Scale(val);
       return val < 0 ? scale[0] : val > 1 ? scale[d3ScaleParts] : scale[Math.round(d3ScaleParts * val)];
     },
@@ -151,7 +150,7 @@ feature = layer.createFeature('line', {selectionAPI: canSelect})
       d.hover = false;
     });
     evt.data.hover = true;
-    console.log(evt.data.id);
+    console.log(evt.data.id, evt.data.callsign);
     this.modified();
     feature.draw();
   });

examples/flights/worker.js

@@ -104,7 +104,7 @@ onmessage = function (evt) {
       });
     }
     // Process each aircraft state.
-    var id, state = {}, last;
+    var id, callsign, state = {}, last;
     data.states.forEach(function (record, idx) {
       // Only process the data if passes some basic checks.
       if (!record.length) {
@@ -122,6 +122,7 @@ onmessage = function (evt) {
         return;
       }
       id = record[rr.icao24];
+      callsign = record[rr.callsign].trim();
       state.time = data.time;
       state.lon = record[rr.longitude];
       state.lat = record[rr.latitude];
@@ -149,7 +150,7 @@ onmessage = function (evt) {
       }
       // Store data in arrays to reduce memory use.
       if (!flights[id]) {
-        flights[id] = {time: [], lon: [], lat: [], z: [], v: [], dir: [], id: id};
+        flights[id] = {time: [], lon: [], lat: [], z: [], v: [], dir: [], id: id, callsign: callsign};
       }
       ['time', 'lon', 'lat', 'z', 'v', 'dir'].forEach(function (key) {
         flights[id][key].push(state[key]);
@@ -169,6 +170,7 @@ onmessage = function (evt) {
           z: [flights[id].z[0] - 1e-6, flights[id].z[0]],
           v: [flights[id].v[0] - 1e-6, flights[id].v[0]],
           dir: [flights[id].dir[0], flights[id].dir[0]],
+          callsign: flights[id].callsign,
           id: flights[id].id
         });
       }

src/canvas/index.js

@@ -9,5 +9,6 @@ module.exports = {
   pixelmapFeature: require('./pixelmapFeature'),
   quadFeature: require('./quadFeature'),
   textFeature: require('./textFeature'),
-  tileLayer: require('./tileLayer')
+  tileLayer: require('./tileLayer'),
+  trackFeature: require('./trackFeature')
 };

src/canvas/trackFeature.js

@@ -0,0 +1,34 @@
+var inherit = require('../inherit');
+var registerFeature = require('../registry').registerFeature;
+var trackFeature = require('../trackFeature');
+
+/**
+ * Create a new instance of class trackFeature.
+ *
+ * @class
+ * @alias geo.canvas.trackFeature
+ * @extends geo.trackFeature
+ * @param {geo.trackFeature.spec} arg
+ * @returns {geo.canvas.trackFeature}
+ */
+var canvas_trackFeature = function (arg) {
+  'use strict';
+  if (!(this instanceof canvas_trackFeature)) {
+    return new canvas_trackFeature(arg);
+  }
+
+  arg = arg || {};
+  trackFeature.call(this, arg);
+
+  var object = require('./object');
+  object.call(this);
+
+  this._init(arg);
+  return this;
+};
+
+inherit(canvas_trackFeature, trackFeature);
+
+// Now register it
+registerFeature('canvas', 'track', canvas_trackFeature);
+module.exports = canvas_trackFeature;

src/index.js

@@ -75,6 +75,7 @@ module.exports = $.extend({
   tileCache: require('./tileCache'),
   tileLayer: require('./tileLayer'),
   timestamp: require('./timestamp'),
+  trackFeature: require('./trackFeature'),
   transform: require('./transform'),
   typedef: require('./typedef'),
   vectorFeature: require('./vectorFeature'),

src/lineFeature.js

@@ -316,7 +316,8 @@ var lineFeature = function (arg) {
         i, j, record, u, v, r;
     for (i = 0; i < m_pointSearchInfo.length; i += 1) {
       record = m_pointSearchInfo[i];
-      if (record.max.x < min.x - record.max.r * scale ||
+      if (!record.max ||
+          record.max.x < min.x - record.max.r * scale ||
           record.min.x > max.x + record.max.r * scale ||
           record.max.y < min.y - record.max.r * scale ||
           record.min.y > max.y + record.max.r * scale) {

src/svg/index.js

@@ -15,6 +15,7 @@ module.exports = {
   quadFeature: require('./quadFeature'),
   renderer: require('./svgRenderer'),
   tileLayer: require('./tileLayer'),
+  trackFeature: require('./trackFeature'),
   uniqueID: require('./uniqueID'),
   vectorFeature: require('./vectorFeature')
 };

src/svg/trackFeature.js

@@ -0,0 +1,34 @@
+var inherit = require('../inherit');
+var registerFeature = require('../registry').registerFeature;
+var trackFeature = require('../trackFeature');
+
+/**
+ * Create a new instance of class trackFeature.
+ *
+ * @class
+ * @alias geo.svg.trackFeature
+ * @extends geo.trackFeature
+ * @param {geo.trackFeature.spec} arg
+ * @returns {geo.svg.trackFeature}
+ */
+var svg_trackFeature = function (arg) {
+  'use strict';
+  if (!(this instanceof svg_trackFeature)) {
+    return new svg_trackFeature(arg);
+  }
+
+  arg = arg || {};
+  trackFeature.call(this, arg);
+
+  var object = require('./object');
+  object.call(this);
+
+  this._init(arg);
+  return this;
+};
+
+inherit(svg_trackFeature, trackFeature);
+
+// Now register it
+registerFeature('svg', 'track', svg_trackFeature);
+module.exports = svg_trackFeature;