rebrand

support converting from HilbertQuadkey to s2Cell.

README.md

@@ -1,10 +1,86 @@
 s2-geometry (JavaScript/ES5.1)
 ======================
 
+| Sponsored by [ppl](https://ppl.family)
+
 A pure JavaScript/ES5.1 port of Google/Niantic's S2 Geometry library (as used by **Ingress**, **Pokemon GO**)
 
 Currently contains basic support for S2Cell
 
+<table>
+<tr>
+<td></td>
+<td>
+Face 2
+<br>
+Orientation A
+
+<a href="http://i.imgur.com/SODO4bT.jpg" target="_face2"><img src="http://i.imgur.com/SODO4bTt.jpg" title="Face 2" alt="Face 2"></a>
+
+<br>
+The North Pole<br>(and Canada / Europe)
+</td>
+<td></td>
+</tr>
+<tr>
+<td>
+Face 0
+<br>
+Orientation A
+
+<a href="http://i.imgur.com/dLI5Zd1.jpg" target="_face0"><img src="http://i.imgur.com/dLI5Zd1t.jpg" title="Face 0" alt="Face 0"></a>
+
+<br>
+Africa
+</td>
+<td>
+Face 1
+<br>
+Orientation D
+
+<a href="http://i.imgur.com/duTLDTV.jpg" target="_face1"><img src="http://i.imgur.com/duTLDTVt.jpg" title="Face 1" alt="Face 1"></a>
+
+<br>
+Asia
+</td>
+<td>
+Face 3
+<br>
+Orientation D
+
+<a href="http://i.imgur.com/6Ho35Tc.jpg" target="_face3"><img src="http://i.imgur.com/6Ho35Tct.jpg" title="Face 3" alt="Face 3"></a>
+
+<br>
+Nothing<br>(and Australia)
+</td>
+<td>
+Face 4
+<br>
+Orientation A
+
+<a href="http://i.imgur.com/3IBAfqj.jpg" target="_face4"><img src="http://i.imgur.com/3IBAfqjt.jpg" title="Face 4" alt="Face 4"></a>
+
+<br>
+The Americas<br>(and Provo, UT)
+</td>
+</tr>
+<tr>
+<td></td>
+<td></td>
+<td></td>
+<td>
+Face 5
+<br>
+Orientation D
+
+<a href="http://i.imgur.com/HZCBvgy.jpg" target="_face5"><img src="http://i.imgur.com/HZCBvgyt.jpg" title="Face 5" alt="Face 5"></a>
+
+<br>
+Antarctica
+</td>
+</tr>
+</table>
+
 Where is this being used?
 ---------------------
 
@@ -16,15 +92,57 @@ Simple Examples
 ---------------
 
 ```javascript
+'use strict';
+
+var S2 = require('s2-geometry').S2;
+
+var lat = 40.2574448;
+var lng = -111.7089464;
 var level = 15;
-var latlng = { lat: 40.2574448, lng: -111.7089464 };
-var cell = S2.S2Cell.FromLatLng(latlng, level);
 
-cell.getNeighbors();  // [ cellLeft, cellDown, cellRight, cellUp ]
 
-cell.getLatLng();     // { lat: 40.2574448, lng: -111.7089464 }
 
-var key = cell.toHilbertQuadkey();
+//
+// Convert from Lat / Lng
+//
+var key = S2.latLngToKey(lat, lng, level);
+// '4/032212303102210'
+
+
+
+//
+// Convert between Hilbert Curve Quadtree Key and S2 Cell Id
+//
+var id = S2.keyToId(key);
+// '9749618446378729472'
+
+var key = S2.idToKey(id);
+// '9749618446378729472'
+
+
+//
+// Convert between Quadkey and Id
+//
+var latlng = S2.keyToLatLng(key);
+var latlng = S2.idToLatLng(id);
+
+
+
+//
+// Neighbors
+//
+var neighbors = S2.latLngToNeighborKeys(lat, lng, level);
+// [ keyLeft, keyDown, keyRight, keyUp ]
+
+
+
+//
+// Previous, Next, and Step
+//
+var nextKey = S2.nextKey(key);
+var prevKey = S2.prevKey(key);
+
+var backTenKeys = S2.stepKey(key, -10);
 ```
 
 Previous and Next
@@ -37,14 +155,16 @@ You can get the previous and next S2CellId from any given Key:
 3. Convert the Key to an Id (uint64 string)
 
 ```javascript
-var key = S2.latLngToKey(40.2574448, -111.7089464);   // '4/032212303102210'
-var id = S2.toId(key);                                // '9749618446378729472'
+var key = S2.latLngToKey(40.2574448, -111.7089464, 15);   // '4/032212303102210'
+var id = S2.keyToId(key);                                 // '9749618446378729472'
 
 var nextKey = S2.nextKey(key);
-var nextId = S2.toId(nextKey);
+var nextId = S2.keyToId(nextKey);
 
 var prevKey = S2.prevKey(key);
-var prevId = S2.toId(prevKey);
+var prevId = S2.keyToId(prevKey);
+
+var backTenKeys = S2.stepKey(key, -10);
 
 // See it
 console.log(prevKey);                                 // '4/032212303102203'
@@ -53,7 +173,7 @@ console.log(nextKey);                                 // '4/032212303102211'
 console.log(nextId);
 ```
 
-convert Cell Id to Quadkey
+convert Cell Id to Hilbert Curve Quad Tree
 ------------------
 
 Convert from base 10 (decimal) `S2 Cell Id` to base 4 `quadkey` (aka hilbert curve quadtree id)
@@ -69,7 +189,7 @@ var face = parts[0];                  // 4
 var position = parts[1];              // '032212303102210';
 var level = '032212303102210'.length; // 15
 
-var cellId = S2.fromFacePosLevel(face, position, level);
+var cellId = S2.facePosLevelToId(face, position, level);
 
 console.log(cellId);
 ```
@@ -83,7 +203,16 @@ Example '9749618446378729472' becomes '4/032212303102210'
 
 var cellId = '9749618446378729472';
 
-var hilbertQuadkey = S2.toHilbertQuadkey(cellId);
+var hilbertQuadkey = S2.idToKey(cellId);
 
 console.log(hilbertQuadkey);
 ```
+
+Convert Key and Id to LatLng
+---------------------
+
+```javascript
+var latlng = S2.keyToLatLng('4/032212303102210');
+
+var latlng = S2.idToLatLng('9749618446378729472');
+```

bower.json

@@ -34,5 +34,6 @@
     "bower_components",
     "test",
     "tests"
-  ]
+  ],
+  "version": "1.2.9"
 }

package.json

@@ -1,6 +1,6 @@
 {
   "name": "s2-geometry",
-  "version": "1.2.4",
+  "version": "1.2.10",
   "description": "A pure JavaScript/ES5.1 port of Google/Niantic's S2 Geometry library (used by Ingress, Pokemon GO)",
   "main": "src/s2geometry.js",
   "scripts": {
@@ -8,7 +8,7 @@
   },
   "repository": {
     "type": "git",
-    "url": "git+https://github.com/Daplie/s2-geometry.js.git"
+    "url": "git+https://git.coolaj86.com/coolaj86/s2-geometry.js.git"
   },
   "keywords": [
     "s2",
@@ -27,12 +27,12 @@
     "lat",
     "lng"
   ],
-  "author": "AJ ONeal <aj@daplie.com> (https://coolaj86.com/)",
-  "license": "ISC",
+  "author": "AJ ONeal <coolaj86@gmail.com> (https://coolaj86.com/)",
+  "license": "(MIT or Apache-2 or ISC)",
   "bugs": {
-    "url": "https://github.com/Daplie/s2-geometry.js/issues"
+    "url": "https://git.coolaj86.com/coolaj86/s2-geometry.js/issues"
   },
-  "homepage": "https://github.com/Daplie/s2-geometry.js#readme",
+  "homepage": "https://git.coolaj86.com/coolaj86/s2-geometry.js#readme",
   "dependencies": {
     "long": "^3.2.0"
   }

src/s2geometry.js

@@ -22,10 +22,29 @@
 // - i,j: they always use 30 bits, adjusting as needed. we use 0 to (1<<level)-1 instead
 //        (so GetSizeIJ for a cell is always 1)
 
-(function(exports) {
+(function (exports) {
 'use strict';
 
-var S2 = exports.S2 = {};
+var S2 = exports.S2 = { L: {} };
+
+S2.L.LatLng = function (/*Number*/ rawLat, /*Number*/ rawLng, /*Boolean*/ noWrap) {
+  var lat = parseFloat(rawLat, 10);
+  var lng = parseFloat(rawLng, 10);
+
+  if (isNaN(lat) || isNaN(lng)) {
+    throw new Error('Invalid LatLng object: (' + rawLat + ', ' + rawLng + ')');
+  }
+
+  if (noWrap !== true) {
+    lat = Math.max(Math.min(lat, 90), -90);                 // clamp latitude into -90..90
+    lng = (lng + 180) % 360 + ((lng < -180 || lng === 180) ? 180 : -180);   // wrap longtitude into -180..180
+  }
+
+  return { lat: lat, lng: lng };
+};
+
+S2.L.LatLng.DEG_TO_RAD = Math.PI / 180;
+S2.L.LatLng.RAD_TO_DEG = 180 / Math.PI;
 
 /*
 S2.LatLngToXYZ = function(latLng) {
@@ -181,12 +200,36 @@ S2.IJToST = function(ij,order,offsets) {
   ];
 };
 
+
+
+var rotateAndFlipQuadrant = function(n, point, rx, ry)
+{
+	var newX, newY;
+	if(ry == 0)
+	{
+		if(rx == 1){
+			point.x = n - 1 - point.x;
+			point.y = n - 1 - point.y
+
+		}
+
+    var x = point.x;
+		point.x = point.y
+		point.y = x;
+	}
+
+}
+
+
+
+
+
 // hilbert space-filling curve
 // based on http://blog.notdot.net/2009/11/Damn-Cool-Algorithms-Spatial-indexing-with-Quadtrees-and-Hilbert-Curves
 // note: rather then calculating the final integer hilbert position, we just return the list of quads
 // this ensures no precision issues whth large orders (S3 cell IDs use up to 30), and is more
 // convenient for pulling out the individual bits as needed later
-var pointToHilbertQuadList = function(x,y,order) {
+var pointToHilbertQuadList = function(x,y,order,face) {
   var hilbertMap = {
     'a': [ [0,'d'], [1,'a'], [3,'b'], [2,'a'] ],
     'b': [ [2,'b'], [1,'b'], [3,'a'], [0,'c'] ],
@@ -194,7 +237,10 @@ var pointToHilbertQuadList = function(x,y,order) {
     'd': [ [0,'a'], [3,'c'], [1,'d'], [2,'d'] ]
   };
 
-  var currentSquare='a';
+  if ('number' !== typeof face) {
+    console.warn(new Error("called pointToHilbertQuadList without face value, defaulting to '0'").stack);
+  }
+  var currentSquare = (face % 2) ? 'd' : 'a';
   var positions = [];
 
   for (var i=order-1; i>=0; i--) {
@@ -218,9 +264,59 @@ var pointToHilbertQuadList = function(x,y,order) {
 
 S2.S2Cell = function(){};
 
+S2.S2Cell.FromHilbertQuadKey = function(hilbertQuadkey) {
+  var parts = hilbertQuadkey.split('/');
+  var face = parseInt(parts[0]);
+  var position = parts[1];
+  var maxLevel = position.length;
+  var point = {
+    x : 0,
+    y: 0
+  };
+  var i;
+  var level;
+  var bit;
+  var rx, ry;
+  var val;
+
+	for(i = maxLevel - 1; i >= 0; i--) {
+
+		level = maxLevel - i;
+		bit = position[i];
+		rx = 0;
+    ry = 0;
+		if (bit === '1') {
+			ry = 1;
+		}
+		else if (bit === '2') {
+			rx = 1;
+			ry = 1;
+		}
+		else if (bit === '3') {
+			rx = 1;
+		}
+
+		val = Math.pow(2, level - 1);
+		rotateAndFlipQuadrant(val, point, rx, ry);
+
+		point.x += val * rx;
+		point.y += val * ry;
+
+	}
+
+  if (face % 2 === 1) {
+    var t = point.x;
+    point.x = point.y;
+    point.y = t;
+  }
+
+
+  return S2.S2Cell.FromFaceIJ(parseInt(face), [point.x, point.y], level);
+};
+
 //static method to construct
 S2.S2Cell.FromLatLng = function(latLng, level) {
-  if (!latLng.lat || !latLng.lng) {
+  if ((!latLng.lat && latLng.lat !== 0) || (!latLng.lng && latLng.lng !== 0)) {
     throw new Error("Pass { lat: lat, lng: lng } to S2.S2Cell.FromLatLng");
   }
   var xyz = S2.LatLngToXYZ(latLng);
@@ -232,6 +328,7 @@ S2.S2Cell.FromLatLng = function(latLng, level) {
 
   return S2.S2Cell.FromFaceIJ (faceuv[0], ij, level);
 };
+
 /*
 S2.faceIjLevelToXyz = function (face, ij, level) {
   var st = S2.IJToST(ij, level, [0.5, 0.5]);
@@ -286,16 +383,21 @@ S2.S2Cell.prototype.getCornerLatLngs = function() {
 
 
 S2.S2Cell.prototype.getFaceAndQuads = function () {
-  var quads = pointToHilbertQuadList(this.ij[0], this.ij[1], this.level);
+  var quads = pointToHilbertQuadList(this.ij[0], this.ij[1], this.level, this.face);
 
   return [this.face,quads];
 };
 S2.S2Cell.prototype.toHilbertQuadkey = function () {
-  var quads = pointToHilbertQuadList(this.ij[0], this.ij[1], this.level);
+  var quads = pointToHilbertQuadList(this.ij[0], this.ij[1], this.level, this.face);
 
   return this.face.toString(10) + '/' + quads.join('');
 };
 
+S2.latLngToNeighborKeys = S2.S2Cell.latLngToNeighborKeys = function (lat, lng, level) {
+  return S2.S2Cell.FromLatLng({ lat: lat, lng: lng }, level).getNeighbors().map(function (cell) {
+    return cell.toHilbertQuadkey();
+  });
+};
 S2.S2Cell.prototype.getNeighbors = function() {
 
   var fromFaceIJWrap = function(face,ij,level) {
@@ -342,7 +444,7 @@ S2.FACE_BITS = 3;
 S2.MAX_LEVEL = 30;
 S2.POS_BITS = (2 * S2.MAX_LEVEL) + 1; // 61 (60 bits of data, 1 bit lsb marker)
 
-S2.fromFacePosLevel = function (faceN, posS, levelN) {
+S2.facePosLevelToId = S2.S2Cell.facePosLevelToId = S2.fromFacePosLevel = function (faceN, posS, levelN) {
   var Long = exports.dcodeIO && exports.dcodeIO.Long || require('long');
   var faceB;
   var posB;
@@ -378,13 +480,19 @@ S2.fromFacePosLevel = function (faceN, posS, levelN) {
   return Long.fromString(bin, true, 2).toString(10);
 };
 
-S2.toId = S2.toCellId = S2.fromKey = function (key) {
+S2.keyToId = S2.S2Cell.keyToId
+= S2.toId = S2.toCellId = S2.fromKey
+= function (key) {
   var parts = key.split('/');
 
   return S2.fromFacePosLevel(parts[0], parts[1], parts[1].length);
 };
 
-S2.toKey = S2.fromId = S2.fromCellId = S2.toHilbertQuadkey = function (idS) {
+S2.idToKey = S2.S2Cell.idToKey
+= S2.S2Cell.toKey = S2.toKey
+= S2.fromId = S2.fromCellId
+= S2.S2Cell.toHilbertQuadkey  = S2.toHilbertQuadkey
+= function (idS) {
   var Long = exports.dcodeIO && exports.dcodeIO.Long || require('long');
   var bin = Long.fromString(idS, true, 10).toString(2);
 
@@ -411,7 +519,21 @@ S2.toKey = S2.fromId = S2.fromCellId = S2.toHilbertQuadkey = function (idS) {
   return faceS + '/' + posS;
 };
 
-S2.latLngToKey = S2.latLngToQuadkey = function (lat, lng, level) {
+S2.keyToLatLng = S2.S2Cell.keyToLatLng = function (key) {
+  var cell2 = S2.S2Cell.FromHilbertQuadKey(key);
+  return cell2.getLatLng();
+};
+
+S2.idToLatLng = S2.S2Cell.idToLatLng = function (id) {
+  var key = S2.idToKey(id);
+  return S2.keyToLatLng(key);
+};
+
+S2.S2Cell.latLngToKey = S2.latLngToKey
+= S2.latLngToQuadkey = function (lat, lng, level) {
+  if (isNaN(level) || level < 1 || level > 30) {
+    throw new Error("'level' is not a number between 1 and 30 (but it should be)");
+  }
   // TODO
   //
   // S2.idToLatLng(id)
@@ -461,45 +583,12 @@ S2.stepKey = function (key, num) {
   return faceS + '/' + otherS;
 };
 
-S2.prevKey = function (key) {
+S2.S2Cell.prevKey = S2.prevKey = function (key) {
   return S2.stepKey(key, -1);
 };
 
-S2.nextKey = function (key) {
+S2.S2Cell.nextKey = S2.nextKey = function (key) {
   return S2.stepKey(key, 1);
 };
 
-})('undefined' !== typeof window ? window : module.exports);
-
-(function (exports) {
-'use strict';
-
-  // Adapted from Leafletjs https://searchcode.com/codesearch/view/42525008/
-
-  var L = {};
-  var S2 = exports.S2;
-
-  if (!exports.L) {
-    exports.L = L;
-  }
-  S2.L = L;
-
-  L.LatLng = function (/*Number*/ rawLat, /*Number*/ rawLng, /*Boolean*/ noWrap) {
-    var lat = parseFloat(rawLat, 10);
-    var lng = parseFloat(rawLng, 10);
-
-    if (isNaN(lat) || isNaN(lng)) {
-      throw new Error('Invalid LatLng object: (' + rawLat + ', ' + rawLng + ')');
-    }
-
-    if (noWrap !== true) {
-      lat = Math.max(Math.min(lat, 90), -90);                 // clamp latitude into -90..90
-      lng = (lng + 180) % 360 + ((lng < -180 || lng === 180) ? 180 : -180);   // wrap longtitude into -180..180
-    }
-
-    return { lat: lat, lng: lng };
-  };
-
-  L.LatLng.DEG_TO_RAD = Math.PI / 180;
-  L.LatLng.RAD_TO_DEG = 180 / Math.PI;
-})('undefined' !== typeof window ? window : module.exports);
+})('undefined' !== typeof module ? module.exports : window);

tests/debug.js

@@ -8,43 +8,72 @@ var lat = -43.525166;
 var lng = 172.655096;
 //var id = '8678661352471920640';
 
-console.log('');
-console.log('Lat/Lng');
-console.log('=', lat + ',' + lng);
+var tests = [
+  [ -13.846153846153854, -41.53846153846155 ]   // face 0
+, [ -13.846153846153854, 96.92307692307692 ]    // face 1
+, [ 41.53846153846153, -124.61538461538463 ]    // face 2
+, [ -152.30769230769232, 41.53846153846153 ]    // face 3
+, [ -152.30769230769232, 69.23076923076923 ]    // face 4
+, [ -124.61538461538463, -69.23076923076924 ]   // face 5
+];
 
-//
-// Lat / Lng to XYZ
-//
-var nS2LatLng = new nS2.S2LatLng(lat, lng).toPoint();
-var nXyz = [ nS2LatLng.x(), nS2LatLng.y(), nS2LatLng.z() ];
-//var oXyz = oS2.LatLngToXYZ({ lat: lat, lng: lng });
-var jXyz = jS2.LatLngToXYZ({ lat: lat, lng: lng });
-console.log('');
-console.log('XYZ');
-console.log('=', nXyz);
-//console.log('o', oXyz);
-console.log('j', jXyz);
+var tests = [
+  [ -3.9832738, 12.6825449,   'The Congo          (Africa)' ]
+, [ 19.0827696, 72.7407752,   'Mumbai, India      (Asia)' ]
+, [ 68.5207533, -74.9563282,  'Greenland          (North Pole)' ]
+, [ -1.573289, -158.957890,   'The Pacific Ocean  (nowhere)' ]
+, [ 40.2573137, -111.7091177, 'Provo, UT, USA     (Americas)' ]
+, [ -46.362972,-73.7431064,   'Antarctica         (South Pole)' ]
+];
+
+var bugReports = [
+  // https://github.com/jonatkins/s2-geometry-javascript/issues/12
+  [ -6.120097, 106.846511, '@Skeec' ]
+  // https://github.com/coolaj86/s2-geometry-javascript/issues/8#issuecomment-237204759
+, [ -33.87347601637759, 151.1954084522501 ]
+  // https://github.com/Daplie/s2-geometry.js/issues/1
+, [ 45.74528835847731, 12.5516625, '@vekexasia' ]
+];
+
+tests.concat(bugReports).forEach(function (pair, i) {
+  var lat = pair[0];
+  var lng = pair[1];
+  var comment = pair[2] && ('(' + pair[2] + ')') || '';
+
+  console.log('');
+  console.log('');
+
+  if (i < 6) {
+    console.log('FACE', i);
+  }
+  console.log('Lat/Lng', '=', lat + ',' + lng, comment);
+
+  //
+  // Lat / Lng to XYZ
+  //
+  var nS2LatLng = new nS2.S2LatLng(lat, lng).toPoint();
+  //var nXyz = [ nS2LatLng.x(), nS2LatLng.y(), nS2LatLng.z() ];
+  //var jXyz = jS2.LatLngToXYZ({ lat: lat, lng: lng });
+  /*
+  console.log('');
+  console.log('XYZ');
+  console.log('=', nXyz);
+  console.log('j', jXyz);
+  */
 
 
-var nCell = new nS2.S2CellId(nS2LatLng).parent(15);
-//var oCell = oS2.S2Cell.FromLatLng({ lat: lat, lng: lng }, 15);
-var jCell = jS2.S2Cell.FromLatLng({ lat: lat, lng: lng }, 15);
-console.log('');
-console.log('F,IJ,L');
-//console.log('=', cellN);
-//console.log('o', oCell.toString());
-console.log('j', jCell.toString());
+  var nCell = new nS2.S2CellId(nS2LatLng).parent(15);
+  var jCell = jS2.S2Cell.FromLatLng({ lat: lat, lng: lng }, 15);
+  /*
+  console.log('');
+  console.log('F,IJ,L');
+  console.log('j', jCell.toString());
+  */
 
-var nKey = nCell.toString();
-//var oQuad = oCell.getFaceAndQuads();
-//var oKey = oQuad[0] + '/' + oQuad[1].join('');
-var jQuad = jCell.getFaceAndQuads();
-var jKey = jQuad[0] + '/' + jQuad[1].join('');
-console.log('');
-console.log('Quadkey');
-console.log('=', nKey);
-//console.log('o', oKey);
-console.log('j', jKey);
-
-//var nCellId = new nS2.S2CellId(id);
-//console.log(nCellId.toLatLng().toString());
+  var nKey = nCell.toString();
+  var jQuad = jCell.getFaceAndQuads();
+  var jKey = jQuad[0] + '/' + jQuad[1].join('');
+  console.log('Quadkey');
+  console.log('=', nKey);
+  console.log('j', jKey, "(" + jS2.toId(jKey) + ")");
+});

tests/exhaustive.js

@@ -0,0 +1,32 @@
+'use strict';
+
+var jS2 = require('../src/s2geometry.js').S2;
+var nS2 = require('s2geometry-node');
+
+var x, y;
+
+function checkReal(lat, lng) {
+  var nS2LatLng = new nS2.S2LatLng(lat, lng).toPoint();
+  var nCell = new nS2.S2CellId(nS2LatLng).parent(15);
+  var jCell = jS2.S2Cell.FromLatLng({ lat: lat, lng: lng }, 15);
+  var nKey = nCell.toString();
+  var jQuad = jCell.getFaceAndQuads();
+  var jKey = jQuad[0] + '/' + jQuad[1].join('');
+
+  if (nKey !== jKey) {
+    console.log('');
+    console.log('Quadkey');
+    console.log('=', nKey);
+    console.log('j', jKey);
+    throw new Error("values didn't match expected");
+  }
+}
+
+console.log('Exhaustive check of about 518,400 random lat,lng coordinates of the earth (about every 0.5°)');
+console.log('(this will take several seconds)');
+for (x = -180; x <= 180; x += (0 + Math.random())) {
+  for (y = -180; y <= 180; y += (0 + Math.random())) {
+    checkReal(x, y);
+  }
+}
+console.log('PASS');

tests/hilbert-to-cell.js

@@ -0,0 +1,36 @@
+'use strict';
+
+var S2 = require('../src/s2geometry.js').S2;
+
+for(var level = 1; level <= 20; level++) {
+	var success = 0;
+	var total = 0;
+	for (var x = -180.0; x < 180; x += 0.5) {
+		for (var y = -180.0; y < 180; y += 0.5) {
+
+				var latlng = { lat: x, lng: y };
+				var cell = S2.S2Cell.FromLatLng(latlng, level);
+				var quadKey = cell.toHilbertQuadkey();
+				var cell2 = S2.S2Cell.FromHilbertQuadKey(quadKey);
+
+				if(cell.face != cell2.face ||
+					cell.ij[0] != cell2.ij[0] ||
+					cell.ij[1] != cell2.ij[1] ||
+					cell.level != cell2.level)
+					{
+						/*console.log({
+							cell: cell,
+							cell2: cell2})*/
+
+					}
+					else
+					{
+						success++;
+					}
+					total++;
+				// check equal
+		}
+	}
+
+	console.log("level:" + level + "\t total:" + total + "\t success:" + success);
+}

tests/js-vs-go.js

@@ -0,0 +1,33 @@
+'use strict';
+
+var tests = require('./generated-locations.json');
+var jS2 = require('../src/s2geometry.js').S2;
+
+function checkReal(loc) {
+  var jCell = jS2.S2Cell.FromLatLng({ lat: loc.lat, lng: loc.lng }, 15);
+  var jQuad = jCell.getFaceAndQuads();
+  var jKey = jQuad[0] + '/' + jQuad[1].join('');
+
+  if (loc.quadkey !== jKey) {
+    loc.badFace = jCell.face;
+    loc.badI = jCell.ij[0];
+    loc.badJ = jCell.ij[1];
+    loc.badQuad = jKey;
+    loc.badId = jS2.toId(jKey);
+    console.log(JSON.stringify(loc, null, '  ') + ',');
+    console.log('');
+    console.log('Lat/Lng:', loc.lat, loc.lng);
+    console.log('');
+    console.log('I, J:');
+    console.log('=', loc.i, loc.j);
+    console.log('j', jCell.ij.join(', '));
+    console.log('');
+    console.log('Quadkey');
+    console.log('=', loc.quadkey);
+    console.log('j', jKey);
+    throw new Error("values didn't match expected");
+  }
+}
+
+tests.forEach(checkReal);
+console.log('PASS');

tests/key-id-to-latlng.js

@@ -0,0 +1,48 @@
+'use strict';
+
+var S2 = require('../src/s2geometry.js').S2;
+var x, y;
+var count = 0;
+
+function refCheck() {
+  var refKey = '4/032212303102210';
+  var latlng = {
+    'lat': 40.2574448
+  , 'lng': -111.7089464
+  };
+
+  var key = S2.latLngToKey(latlng.lat, latlng.lng, 15);
+  if (key !== refKey) {
+    throw new Error("reference doesn't match");
+  }
+
+  var latlng1 = S2.keyToLatLng('4/032212303102210');
+  var key1 = S2.latLngToKey(latlng1.lat, latlng1.lng, 15);
+  if (key1 !== refKey) {
+    throw new Error("reference 1 doesn't match");
+  }
+
+  var latlng2 = S2.idToLatLng('9749618446378729472');
+  var key2 = S2.latLngToKey(latlng2.lat, latlng2.lng, 15);
+  if (key2 !== refKey) {
+    throw new Error("reference 2 doesn't match");
+  }
+}
+
+function checkReal(lat, lng) {
+  var key = S2.latLngToKey(lat, lng, 15);
+  var latlng = S2.keyToLatLng(key);
+  var key2 = S2.latLngToKey(latlng.lat, latlng.lng, 15);
+  if (key !== key2) {
+    throw new Error("keys do not match", latlng, key, key2);
+  }
+}
+
+for (x = -180; x <= 180; x += (0 + Math.random())) {
+  for (y = -180; y <= 180; y += (0 + Math.random())) {
+    count += 1;
+    checkReal(x, y);
+  }
+}
+
+console.log('PASS:', count, 'random locations without any key mismatches');

tests/s2-node-hilbert.js

@@ -1,4 +1,4 @@
-var S2 = require('s2geometry-node');
+var s2n = require('s2geometry-node');
 
 // Provo, UT (Center St)
 //var lat = 40.2574448;
@@ -16,8 +16,8 @@ var S2 = require('s2geometry-node');
 var lat = -43.5261282;
 var lng = 172.6561085;
 
-var s2latlng = new S2.S2LatLng(lat, lng);
-var cellId = new S2.S2CellId(s2latlng).parent(15);
+var s2nlatlng = new s2n.S2LatLng(lat, lng);
+var cellId = new s2n.S2CellId(s2nlatlng).parent(15);
 var cell;
 
 var walk = [];
@@ -47,6 +47,6 @@ walk.forEach(function (parts) {
   var i = parts[0];
   var cellId = parts[1];
 
-  cell = new S2.S2Cell(cellId);
+  cell = new s2n.S2Cell(cellId);
   console.log(i, cell.face(), cellId.id(), cellId.toString(), cellId.toLatLng().toString(), cellId.level());
 });

tests/simple.js

@@ -0,0 +1,51 @@
+'use strict';
+
+var S2 = require('../src/s2geometry.js').S2;
+
+var lat = 40.2574448;
+var lng = -111.7089464;
+var level = 15;
+
+
+
+//
+// Convert from Lat / Lng
+//
+var key = S2.latLngToKey(lat, lng, level);
+console.log(key);
+// '4/032212303102210'
+
+
+
+//
+// Convert between Hilbert Curve Quadtree Key and S2 Cell Id
+//
+var id = S2.keyToId(key);
+console.log(id);
+// '9749618446378729472'
+
+var key = S2.idToKey(id);
+console.log(key);
+// '9749618446378729472'
+
+
+
+//
+// Neighbors
+//
+var neighbors = S2.latLngToNeighborKeys(lat, lng, level);
+console.log(neighbors);
+// [ keyLeft, keyDown, keyRight, keyUp ]
+
+
+
+//
+// Previous, Next, and Step
+//
+var nextKey = S2.nextKey(key);
+console.log(nextKey);
+var prevKey = S2.prevKey(key);
+console.log(prevKey);
+
+var backTenKeys = S2.stepKey(key, -10);
+console.log(backTenKeys);