add bezier smoothing to tracks

CHANGELOG.md

@@ -1,5 +1,6 @@
 ### Change Log for Node-RED Worldmap
 
+ - v2.11.0 - Add option to smooth tracks using bezier curves.
  - v2.10.0 - Save latest position to browser for refresh if in iframe/dashboard. Allow fractional Zoom levels.
  - v2.9.0 - Let weblinks be an array of links. Add more info to readme about Mapservers.
  - v2.8.9 - Only load cgi module if we have a local mapserv file

README.md

@@ -11,6 +11,7 @@ map web page for plotting "things" on.
 
 ### Updates
 
+- v2.11.0 - Add option to smooth tracks using bezier curves.
 - v2.10.0 - Save latest position to browser for refresh if in iframe/dashboard. Allow fractional Zoom levels.
 - v2.9.0 - Let weblinks be an array of links. Add more info to readme about Mapservers.
 - v2.8.9 - Only load cgi module if we have a local mapserv file.

package.json

@@ -1,12 +1,13 @@
 {
     "name": "node-red-contrib-web-worldmap",
-    "version": "2.10.0",
+    "version": "2.11.0",
     "description": "A Node-RED node to provide a web page of a world map for plotting things on.",
     "dependencies": {
         "cgi": "0.3.1",
         "compression": "^1.7.4",
         "express": "^4.16.4",
-        "sockjs": "~0.3.21"
+        "sockjs": "~0.3.21",
+        "@turf/bezier-spline": "*"
     },
     "bundledDependencies": [
         "cgi",

worldmap.html

@@ -528,6 +528,11 @@ then by default <code>⌘⇧m</code> - <code>ctrl-shift-m</code> will load the m
             <option value="single">single Track layer</option>
         </select>
     </div>
+    <div class="form-row">
+        <label>&nbsp;</label>
+        <input type="checkbox" id="node-input-smooth" style="display:inline-block; width:auto; vertical-align:top;">
+        <label for="node-input-smooth" style="width:70%;">Smooth tracks using bezier curves.</label>
+    </div>
     <div class="form-row">
         <label for="node-input-name"><i class="fa fa-file"></i> Name</label>
         <input type="text" id="node-input-name" placeholder="name">
@@ -553,7 +558,8 @@ then by default <code>⌘⇧m</code> - <code>ctrl-shift-m</code> will load the m
             defaults: {
                 name: {value:""},
                 depth: {value:20},
-                layer: {value:"combined"}
+                layer: {value:"combined"},
+                smooth: {value:false}
             },
             inputs:1,
             outputs:1,

worldmap.js

@@ -273,7 +273,9 @@ module.exports = function(RED) {
         this.depth = parseInt(Number(n.depth) || 20);
         this.pointsarray = {};
         this.layer = n.layer || "combined"; // separate, single
+        this.smooth = n.smooth || false;
         var node = this;
+        var bezierSpline = require("@turf/bezier-spline").default;
 
         var doTrack = function(msg) {
             if (msg.hasOwnProperty("payload") && msg.payload.hasOwnProperty("name")) {
@@ -335,7 +337,13 @@ module.exports = function(RED) {
                     }
                 }
                 if (line.length > 1) { // only send track if two points or more
+                    if (node.smooth) {
+                        var curved = bezierSpline({"type":"Feature", "properties":{}, "geometry":{"type":"LineString", "coordinates":line }});
+                        newmsg.payload.line = curved.geometry.coordinates;
+                    }
+                    else {
                         newmsg.payload.line = line;
+                    }
                     newmsg.payload.name = msg.payload.name + "_";
                     if (node.layer === "separate") {
                         newmsg.payload.layer = msg.payload.layer + " tracks";