add geodesy plugin and area block

3 files changed, 200 insertions, 1 deletions

diff --git a/leaflet-geodesy.js b/leaflet-geodesy.js
new file mode 100644
index 0000000..359b4ab
--- /dev/null
+++ b/leaflet-geodesy.js
@@ -0,0 +1,198 @@
+!function(e){"object"==typeof exports?module.exports=e():"function"==typeof define&&define.amd?define(e):"undefined"!=typeof window?window.LGeo=e():"undefined"!=typeof global?global.LGeo=e():"undefined"!=typeof self&&(self.LGeo=e())}(function(){var define,module,exports;return (function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);throw new Error("Cannot find module '"+o+"'")}var f=n[o]={exports:{}};t[o][0].call(f.exports,function(e){var n=t[o][1][e];return s(n?n:e)},f,f.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(require,module,exports){
+var spherical = require('spherical'),
+    geojsonArea = require('geojson-area'),
+    wgs84 = require('wgs84');
+
+module.exports.circle = function(center, radius, opt) {
+    center = L.latLng(center);
+    opt = opt || {};
+    var parts = opt.parts || 20;
+
+    function generate(center) {
+        var lls = [];
+        var angularRadius = radius / wgs84.RADIUS * 180 / Math.PI;
+
+        for (var i = 0; i < parts + 1; i++) {
+            lls.push(spherical.radial(
+                [center.lng, center.lat],
+                (i / parts) * 360, radius).reverse());
+        }
+
+        if (angularRadius > (90 - center.lat)) {
+            lls.push([lls[0][0], center.lng + 180],
+                [90, center.lng + 180],
+                [90, center.lng - 180],
+                [lls[0][0], center.lng - 180]);
+        }
+
+        if (angularRadius > (90 + center.lat)) {
+            lls.splice((parts >> 1) + 1, 0,
+                [lls[(parts>>1)][0], center.lng-180 ],
+                [-90, center.lng-180],
+                [-90, center.lng+180],
+                [lls[(parts >> 1)][0], center.lng+180 ]);
+        }
+
+        return lls;
+    }
+
+    var poly = L.polygon(generate(center), opt);
+
+    poly.setLatLng = function(_) {
+        center = _;
+        poly.setLatLngs(generate(center));
+        return poly;
+    };
+
+    poly.getRadius = function(_) {
+        return radius;
+    };
+
+    poly.setRadius = function(_) {
+        radius = _;
+        poly.setLatLngs(generate(center));
+        return poly;
+    };
+
+    return poly;
+};
+
+module.exports.area = function(layer) {
+    var gj = layer.toGeoJSON();
+    return geojsonArea(gj.geometry);
+};
+
+},{"geojson-area":2,"spherical":4,"wgs84":6}],2:[function(require,module,exports){
+var wgs84 = require('wgs84');
+
+module.exports = function(_) {
+    if (_.type === 'Polygon') return polygonArea(_.coordinates);
+    else if (_.type === 'MultiPolygon') {
+        var area = 0;
+        for (var i = 0; i < _.coordinates.length; i++) {
+            area += polygonArea(_.coordinates[i]);
+        }
+        return area;
+    } else {
+        return null;
+    }
+};
+
+function polygonArea(coords) {
+    var area = 0;
+    if (coords && coords.length > 0) {
+        area += Math.abs(ringArea(coords[0]));
+        for (var i = 1; i < coords.length; i++) {
+            area -= Math.abs(ringArea(coords[i]));
+        }
+    }
+    return area;
+}
+
+/**
+ * Calculate the approximate area of the polygon were it projected onto
+ *     the earth.  Note that this area will be positive if ring is oriented
+ *     clockwise, otherwise it will be negative.
+ *
+ * Reference:
+ * Robert. G. Chamberlain and William H. Duquette, "Some Algorithms for
+ *     Polygons on a Sphere", JPL Publication 07-03, Jet Propulsion
+ *     Laboratory, Pasadena, CA, June 2007 http://trs-new.jpl.nasa.gov/dspace/handle/2014/40409
+ *
+ * Returns:
+ * {float} The approximate signed geodesic area of the polygon in square
+ *     meters.
+ */
+function ringArea(coords) {
+    var area = 0;
+
+    if (coords.length > 2) {
+        var p1, p2;
+        for (var i = 0; i < coords.length - 1; i++) {
+            p1 = coords[i];
+            p2 = coords[i + 1];
+            area += rad(p2[0] - p1[0]) * (2 + Math.sin(rad(p1[1])) + Math.sin(rad(p2[1])));
+        }
+
+        area = area * wgs84.RADIUS * wgs84.RADIUS / 2;
+    }
+
+    return area;
+}
+
+function rad(_) {
+    return _ * Math.PI / 180;
+}
+
+},{"wgs84":3}],3:[function(require,module,exports){
+module.exports.RADIUS = 6378137;
+module.exports.FLATTENING = 1/298.257223563;
+module.exports.POLAR_RADIUS = 6356752.3142;
+
+},{}],4:[function(require,module,exports){
+var wgs84 = require('wgs84');
+
+module.exports.heading = function(from, to) {
+    var y = Math.sin(Math.PI * (from[0] - to[0]) / 180) * Math.cos(Math.PI * to[1] / 180);
+    var x = Math.cos(Math.PI * from[1] / 180) * Math.sin(Math.PI * to[1] / 180) -
+        Math.sin(Math.PI * from[1] / 180) * Math.cos(Math.PI * to[1] / 180) * Math.cos(Math.PI * (from[0] - to[0]) / 180);
+    return 180 * Math.atan2(y, x) / Math.PI;
+};
+
+module.exports.distance = function(from, to) {
+    var sinHalfDeltaLon = Math.sin(Math.PI * (to[0] - from[0]) / 360);
+    var sinHalfDeltaLat = Math.sin(Math.PI * (to[1] - from[1]) / 360);
+    var a = sinHalfDeltaLat * sinHalfDeltaLat +
+        sinHalfDeltaLon * sinHalfDeltaLon * Math.cos(Math.PI * from[1] / 180) * Math.cos(Math.PI * to[1] / 180);
+    return 2 * wgs84.RADIUS * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
+};
+
+module.exports.radial = function(from, tc_deg, d_m, wrap) {
+    var tc = rad(tc_deg);
+    var d = d_m / wgs84.RADIUS;
+
+    var lon1 = rad(from[0]),
+        lat1 = rad(from[1]);
+
+    var lat = Math.asin(
+        Math.sin(lat1) *
+        Math.cos(d) +
+        Math.cos(lat1) *
+        Math.sin(d) *
+        Math.cos(tc));
+
+    var dlon = Math.atan2(
+        Math.sin(tc) *
+        Math.sin(d) *
+        Math.cos(lat1),
+        Math.cos(d) -
+        Math.sin(lat1) *
+        Math.sin(lat));
+
+    var lon;
+    if (wrap) {
+        lon = (lon1 - dlon + Math.PI) %
+            (2 * Math.PI) - Math.PI;
+    } else {
+        lon = (lon1 - dlon + Math.PI) - Math.PI;
+    }
+
+    return [deg(lon), deg(lat)];
+};
+
+function rad(_) {
+    return _ * (Math.PI / 180);
+}
+
+function deg(_) {
+    return _ * (180 / Math.PI);
+}
+
+},{"wgs84":5}],5:[function(require,module,exports){
+module.exports=require(3)
+},{}],6:[function(require,module,exports){
+module.exports=require(3)
+},{}]},{},[1])
+(1)
+});
+;
\ No newline at end of file
diff --git a/overpass.xml b/overpass.xml
index 3960a51..9299943 100644
--- a/overpass.xml
+++ b/overpass.xml
@@ -1 +1 @@
-<blocks app="Snap! 4.0, http://snap.berkeley.edu" version="1"><block-definition s="ist eine Straße nahe Längengrad: %&apos;lon&apos; Breitengrad: %&apos;lat&apos;" type="predicate" category="sensing"><header></header><code></code><inputs><input type="%n"></input><input type="%n"></input></inputs><script><block s="doReport"><block s="reportGreaterThan"><block s="reportListLength"><block s="overpassQuery"><block s="reportJoinWords"><list><l>way(around:7,</l><block var="lat"/><l>,</l><block var="lon"/><l>)[highway];out;</l></list></block></block></block><l>0</l></block></block></script></block-definition><block-definition s="ist ein Gebäude nahe Längengrad: %&apos;lon&apos; Breitengrad: %&apos;lat&apos;" type="predicate" category="sensing"><header></header><code></code><inputs><input type="%n"></input><input type="%n"></input></inputs><script><block s="doReport"><block s="reportGreaterThan"><block s="reportListLength"><block s="overpassQuery"><block s="reportJoinWords"><list><l>way(around:5,</l><block var="lat"/><l>,</l><block var="lon"/><l>)[building];out;</l></list></block></block></block><l>0</l></block></block></script></block-definition></blocks>
\ No newline at end of file
+<blocks app="Snap! 4.0, http://snap.berkeley.edu" version="1"><block-definition s="ist eine Straße nahe Längengrad: %&apos;lon&apos; Breitengrad: %&apos;lat&apos;" type="predicate" category="sensing"><header></header><code></code><inputs><input type="%n"></input><input type="%n"></input></inputs><script><block s="doReport"><block s="reportGreaterThan"><block s="reportListLength"><block s="overpassQuery"><block s="reportJoinWords"><list><l>way(around:7,</l><block var="lat"/><l>,</l><block var="lon"/><l>)[highway];out;</l></list></block></block></block><l>0</l></block></block></script></block-definition><block-definition s="ist ein Gebäude nahe Längengrad: %&apos;lon&apos; Breitengrad: %&apos;lat&apos;" type="predicate" category="sensing"><header></header><code></code><inputs><input type="%n"></input><input type="%n"></input></inputs><script><block s="doReport"><block s="reportGreaterThan"><block s="reportListLength"><block s="overpassQuery"><block s="reportJoinWords"><list><l>way(around:5,</l><block var="lat"/><l>,</l><block var="lon"/><l>)[building];out;</l></list></block></block></block><l>0</l></block></block></script></block-definition><block-definition s="Größe des von mit %&apos;SpriteName&apos; s Farbe markierten Feldes" type="reporter" category="sensing"><header></header><code></code><inputs><input type="%txt">Sprite</input></inputs><script><block s="doReport"><block s="evaluate"><block s="reportJSFunction"><list><l>spriteName</l></list><l>var size = 0, layers = window.penShapes.getLayers(), sprites = world.children[0].sprites.asArray(), sprite;&#xD;for (j = 0; j &lt; sprites.length; j++) {&#xD; if (sprites[j].name == spriteName) {&#xD; sprite = sprites[j];&#xD; break;&#xD; }&#xD;}&#xD;if (!sprite) {&#xD; return 0;&#xD;}&#xD;for (j = 0; j &lt; layers.length; j++) {&#xD; if (layers[j].options.color == sprite.color) {&#xD; size += LGeo.area(layers[j]);&#xD; }&#xD;}&#xD;return size;</l></block><list><block var="SpriteName"/></list></block></block></script></block-definition></blocks>
\ No newline at end of file
diff --git a/snap.html b/snap.html
index 4542c92..58ebd70 100755
--- a/snap.html
+++ b/snap.html
@@ -9,6 +9,7 @@
         <script type="text/javascript" src="leaflet.js"></script>
         <script type="text/javascript" src="OSMBuildings-Leaflet.js"></script>
         <script type="text/javascript" src="Leaflet.Coordinates-0.1.4.min.js"></script>
+        <script type="text/javascript" src="leaflet-geodesy.js"></script>
         <script type="text/javascript" src="peer.js"></script>
         <script type="text/javascript" src="morphic.js"></script>
         <script type="text/javascript" src="widgets.js"></script>