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s2-geometry.js
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update docs and aliases

This commit is contained in:
AJ ONeal 2016-08-03 17:43:35 -06:00
parent bb664af25b
commit f96e16c6bf
4 changed files with 110 additions and 42 deletions
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61
README.md
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@ -16,15 +16,50 @@ 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'
//
// 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 +72,16 @@ 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 +90,7 @@ 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 +106,7 @@ 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 +120,7 @@ Example '9749618446378729472' becomes '4/032212303102210'
var cellId = '9749618446378729472';
var hilbertQuadkey = S2.toHilbertQuadkey(cellId);
var hilbertQuadkey = S2.idToKey(cellId);
console.log(hilbertQuadkey);
```

55
src/s2geometry.js
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@ -186,7 +186,7 @@ S2.IJToST = function(ij,order,offsets) {
// 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,sq) {
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 +194,10 @@ var pointToHilbertQuadList = function(x,y,order,sq) {
'd': [ [0,'a'], [3,'c'], [1,'d'], [2,'d'] ]
};
var currentSquare=sq||'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--) {
@ -286,36 +289,21 @@ S2.S2Cell.prototype.getCornerLatLngs = function() {
S2.S2Cell.prototype.getFaceAndQuads = function () {
var sq;
switch(this.face) {
case 0:
/* fallthru */
case 2:
/* fallthru */
case 4:
sq = 'a';
break;
case 1:
/* fallthru */
case 3:
/* fallthru */
case 5:
sq = 'd';
break;
}
var quads = pointToHilbertQuadList(this.ij[0], this.ij[1], this.level, sq);
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) {
@ -362,7 +350,7 @@ 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;
@ -398,13 +386,19 @@ 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);
@ -431,7 +425,8 @@ S2.toKey = S2.fromId = S2.fromCellId = S2.toHilbertQuadkey = function (idS) {
return faceS + '/' + posS;
};
S2.latLngToKey = S2.latLngToQuadkey = function (lat, lng, level) {
S2.S2Cell.latLngToKey = S2.latLngToKey
= S2.latLngToQuadkey = function (lat, lng, level) {
// TODO
//
// S2.idToLatLng(id)
@ -481,11 +476,11 @@ 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);
};

12
tests/js-vs-go.js
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@ -9,6 +9,18 @@ function checkReal(loc) {
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);

24
tests/simple.js Normal file
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@ -0,0 +1,24 @@
'use strict';
var S2 = require('../src/s2geometry.js').S2;
var lat = 40.2574448;
var lng = -111.7089464;
var level = 15;
var key = S2.latLngToKey(lat, lng, level);
// '4/032212303102210'
console.log(key);
var id = S2.keyToId(key);
// '9749618446378729472'
console.log(id);
var neighbors = S2.latLngToNeighborKeys(lat, lng, level);
// [ keyLeft, keyDown, keyRight, keyUp ]
console.log(neighbors);
var nextKey = S2.nextKey(key);
console.log(nextKey);
var prevKey = S2.prevKey(key);
console.log(prevKey);