Merge pull request #608 from pelias/coordinate_wrapping

wrap coordinates at poles
8 years ago · 935ac4f1b7
7 changed files with 309 additions and 4 deletions
--- a/sanitiser/_geo_common.js
+++ b/sanitiser/_geo_common.js
@ -4,6 +4,7 @@
 var groups = require('./_groups'),
    util = require('util'),
    check = require('check-types'),
+    wrap = require('./wrap'),
    _ = require('lodash');

 /**
@ -68,6 +69,7 @@ function sanitize_circle( key_prefix, clean, raw, circle_is_required ) {
 * @param {bool} point_is_required
 */
 function sanitize_point( key_prefix, clean, raw, point_is_required ) {
+
  // calculate full property names from the key_prefix
  var properties = [ 'lat', 'lon'].map(function(prop) {
    return key_prefix + '.' + prop;
@ -91,6 +93,11 @@ function sanitize_point( key_prefix, clean, raw, point_is_required ) {
  properties.forEach(function(prop) {
    sanitize_coord(prop, clean, raw, true);
  });
+
+  // normalize co-ordinates by wrapping around the poles
+  var normalized = wrap(clean[properties[0]], clean[properties[1]]);
+  clean[properties[0]] = normalized.lat;
+  clean[properties[1]] = normalized.lon;
 }

 /**
@ -103,6 +110,7 @@ function sanitize_point( key_prefix, clean, raw, point_is_required ) {
 */
 function sanitize_coord( key, clean, raw, latlon_is_required ) {
  var parsedValue = parseFloat( raw[key] );
+
  if ( _.isFinite( parsedValue ) ) {
    clean[key] = parsedValue;
  }
--- a/sanitiser/wrap.js
+++ b/sanitiser/wrap.js
@ -0,0 +1,50 @@
+
+/**
+  normalize co-ordinates that lie outside of the normal ranges.
+
+  longitude wrapping simply requires adding +- 360 to the value until it comes
+  in to range.
+
+  for the latitude values we need to flip the longitude whenever the latitude
+  crosses a pole.
+**/
+
+
+function wrap( lat, lon ){
+
+  var point = { lat: lat, lon: lon };
+  var quadrant = Math.floor( Math.abs(lat) / 90) % 4;
+  var pole = ( lat > 0 ) ? 90 : -90;
+  var offset = lat % 90;
+
+  switch( quadrant ){
+    case 0:
+      point.lat = offset;
+      break;
+    case 1:
+      point.lat = pole - offset;
+      point.lon += 180;
+      break;
+    case 2:
+      point.lat = -offset;
+      point.lon += 180;
+      break;
+    case 3:
+      point.lat = -pole + offset;
+      break;
+  }
+
+  // reduce lon
+  while( point.lon > 180 ){
+    point.lon -= 360;
+  }
+
+  // increase lon
+  while( point.lon < -180 ){
+    point.lon += 360;
+  }
+
+  return point;
+}
+
+module.exports = wrap;
--- a/test/unit/run.js
+++ b/test/unit/run.js
@ -56,6 +56,7 @@ var tests = [
  require('./sanitiser/place'),
  require('./sanitiser/reverse'),
  require('./sanitiser/search'),
+  require('./sanitiser/wrap'),
  require('./service/mget'),
  require('./service/search'),
 ];
--- a/test/unit/sanitiser/_geo_common.js
+++ b/test/unit/sanitiser/_geo_common.js
@ -12,6 +12,65 @@ module.exports.tests.interface = function(test, common) {
  });
 };

+// @note: for better coverage see unit tests for 'wrap.js'.
+module.exports.tests.wrapping = function(test, common) {
+  test('control - no wrapping required', function (t) {
+    var clean = {};
+    var params = {
+      'point.lat': +1.1,
+      'point.lon': -1.1
+    };
+    sanitize.sanitize_point( 'point', clean, params, false );
+    t.equal(clean['point.lat'], +1.1, 'not changed');
+    t.equal(clean['point.lon'], -1.1, 'not changed');
+    t.end();
+  });
+  test('positive longitude wrapping', function (t) {
+    var clean = {};
+    var params = {
+      'point.lat': +1.1,
+      'point.lon': +181.1
+    };
+    sanitize.sanitize_point( 'point', clean, params, false );
+    t.equal(clean['point.lat'], +1.1, 'not changed');
+    t.equal(clean['point.lon'], -178.9, 'equal to (-180 + 1.1)');
+    t.end();
+  });
+  test('negative longitude wrapping', function (t) {
+    var clean = {};
+    var params = {
+      'point.lat': -1.1,
+      'point.lon': -181.1
+    };
+    sanitize.sanitize_point( 'point', clean, params, false );
+    t.equal(clean['point.lat'], -1.1, 'not changed');
+    t.equal(clean['point.lon'], +178.9, 'equal to (+180 - 1.1)');
+    t.end();
+  });
+  test('positive latitudinal wrapping', function (t) {
+    var clean = {};
+    var params = {
+      'point.lat': 91.1,
+      'point.lon': 1.1
+    };
+    sanitize.sanitize_point( 'point', clean, params, false );
+    t.equal(clean['point.lat'], +88.9, 'equal to (+90 - 1.1)');
+    t.equal(clean['point.lon'], -178.9, 'equal to (-180 + 1.1)'); // polar flip
+    t.end();
+  });
+  test('negative latitudinal wrapping', function (t) {
+    var clean = {};
+    var params = {
+      'point.lat': -91.1,
+      'point.lon': -1.1
+    };
+    sanitize.sanitize_point( 'point', clean, params, false );
+    t.equal(clean['point.lat'], -88.9, 'equal to (-90 + 1.1)');
+    t.equal(clean['point.lon'], +178.9, 'equal to (+180 - 1.1)'); // polar flip
+    t.end();
+  });
+};
+
 module.exports.tests.coord = function(test, common) {
  test('valid coord', function (t) {
    var clean = {};
--- a/test/unit/sanitiser/reverse.js
+++ b/test/unit/sanitiser/reverse.js
@ -65,7 +65,6 @@ module.exports.tests.sanitize_lat = function(test, common) {
      sanitize(req, function(){
        var expected_lat = parseFloat( lat );
        t.deepEqual(req.errors, [], 'no errors');
-        t.equal(req.clean['point.lat'], expected_lat, 'clean set correctly (' + lat + ')');
      });
    });
    t.end();
@ -93,7 +92,6 @@ module.exports.tests.sanitize_lon = function(test, common) {
      sanitize(req, function(){
        var expected_lon = parseFloat( lon );
        t.deepEqual(req.errors, [], 'no errors');
-        t.equal(req.clean['point.lon'], expected_lon, 'clean set correctly (' + lon + ')');
      });
    });
    t.end();
--- a/test/unit/sanitiser/search.js
+++ b/test/unit/sanitiser/search.js
@ -129,7 +129,6 @@ module.exports.tests.sanitize_lat = function(test, common) {
      sanitize(req, function(){
        var expected_lat = parseFloat( lat );
        t.equal(req.errors[0], undefined, 'no error');
-        t.equal(req.clean['focus.point.lat'], expected_lat, 'clean lat set correctly (' + lat + ')');
      });
    });
    t.end();
@ -146,7 +145,6 @@ module.exports.tests.sanitize_lon = function(test, common) {
      sanitize( req, function(){
        var expected_lon = parseFloat( lon );
        t.equal(req.errors[0], undefined, 'no error');
-        t.deepEqual(req.clean['focus.point.lon'], expected_lon, 'clean set correctly (' + lon + ')');
      });
    });
    t.end();
--- a/test/unit/sanitiser/wrap.js
+++ b/test/unit/sanitiser/wrap.js
@ -0,0 +1,191 @@
+
+var wrap = require('../../../sanitiser/wrap');
+
+module.exports.tests = {};
+
+module.exports.tests.control = function(test, common) {
+  test('control - no wrapping required', function (t) {
+    var norm = wrap(55.555, 22.222);
+    t.equal(norm.lat, 55.555);
+    t.equal(norm.lon, 22.222);
+    t.end();
+  });
+};
+
+module.exports.tests.latitude_positive = function(test, common) {
+  test('positive latitude wrapping - 1 degree', function (t) {
+    var norm = wrap(1, 0);
+    t.equal(norm.lat, 1);
+    t.equal(norm.lon, 0);
+    t.end();
+  });
+  test('positive latitude wrapping - 91 degrees', function (t) {
+    var norm = wrap(91, 0);
+    t.equal(norm.lat, 89);
+    t.equal(norm.lon, 180);
+    t.end();
+  });
+  test('positive latitude wrapping - 181 degrees', function (t) {
+    var norm = wrap(181, 0);
+    t.equal(norm.lat, -1);
+    t.equal(norm.lon, 180);
+    t.end();
+  });
+  test('positive latitude wrapping - 271 degrees', function (t) {
+    var norm = wrap(271, 0);
+    t.equal(norm.lat, -89);
+    t.equal(norm.lon, 0);
+    t.end();
+  });
+  test('positive latitude wrapping - 361 degrees', function (t) {
+    var norm = wrap(361, 0);
+    t.equal(norm.lat, 1);
+    t.equal(norm.lon, 0);
+    t.end();
+  });
+  test('positive latitude wrapping - 631 degrees', function (t) {
+    var norm = wrap(631, 0);
+    t.equal(norm.lat, -89);
+    t.equal(norm.lon, 0);
+    t.end();
+  });
+  test('positive latitude wrapping - 721 degrees', function (t) {
+    var norm = wrap(721, 0);
+    t.equal(norm.lat, 1);
+    t.equal(norm.lon, 0);
+    t.end();
+  });
+};
+
+module.exports.tests.latitude_negative = function(test, common) {
+  test('negative latitude wrapping - 1 degree', function (t) {
+    var norm = wrap(-1, 0);
+    t.equal(norm.lat, -1);
+    t.equal(norm.lon, 0);
+    t.end();
+  });
+  test('negative latitude wrapping - 91 degrees', function (t) {
+    var norm = wrap(-91, 0);
+    t.equal(norm.lat, -89);
+    t.equal(norm.lon, 180);
+    t.end();
+  });
+  test('negative latitude wrapping - 181 degrees', function (t) {
+    var norm = wrap(-181, 0);
+    t.equal(norm.lat, 1);
+    t.equal(norm.lon, 180);
+    t.end();
+  });
+  test('negative latitude wrapping - 271 degrees', function (t) {
+    var norm = wrap(-271, 0);
+    t.equal(norm.lat, 89);
+    t.equal(norm.lon, 0);
+    t.end();
+  });
+  test('negative latitude wrapping - 361 degrees', function (t) {
+    var norm = wrap(-361, 0);
+    t.equal(norm.lat, -1);
+    t.equal(norm.lon, 0);
+    t.end();
+  });
+  test('negative latitude wrapping - 631 degrees', function (t) {
+    var norm = wrap(-631, 0);
+    t.equal(norm.lat, 89);
+    t.equal(norm.lon, 0);
+    t.end();
+  });
+  test('positive latitude wrapping - 721 degrees', function (t) {
+    var norm = wrap(721, 0);
+    t.equal(norm.lat, 1);
+    t.equal(norm.lon, 0);
+    t.end();
+  });
+};
+
+module.exports.tests.longitude_positive = function(test, common) {
+  test('positive longitude wrapping - 1 degree', function (t) {
+    var norm = wrap(0, 1);
+    t.equal(norm.lat, 0);
+    t.equal(norm.lon, 1);
+    t.end();
+  });
+  test('positive longitude wrapping - 181 degrees', function (t) {
+    var norm = wrap(0, 181);
+    t.equal(norm.lat, 0);
+    t.equal(norm.lon, -179);
+    t.end();
+  });
+  test('positive longitude wrapping - 271 degrees', function (t) {
+    var norm = wrap(0, 271);
+    t.equal(norm.lat, 0);
+    t.equal(norm.lon, -89);
+    t.end();
+  });
+  test('positive longitude wrapping - 361 degrees', function (t) {
+    var norm = wrap(0, 361);
+    t.equal(norm.lat, 0);
+    t.equal(norm.lon, 1);
+    t.end();
+  });
+  test('positive longitude wrapping - 631 degrees', function (t) {
+    var norm = wrap(0, 631);
+    t.equal(norm.lat, 0);
+    t.equal(norm.lon, -89);
+    t.end();
+  });
+  test('positive longitude wrapping - 721 degrees', function (t) {
+    var norm = wrap(0, 721);
+    t.equal(norm.lat, 0);
+    t.equal(norm.lon, 1);
+    t.end();
+  });
+};
+
+module.exports.tests.longitude_negative = function(test, common) {
+  test('negative longitude wrapping - 1 degree', function (t) {
+    var norm = wrap(0, -1);
+    t.equal(norm.lat, 0);
+    t.equal(norm.lon, -1);
+    t.end();
+  });
+  test('negative longitude wrapping - 181 degrees', function (t) {
+    var norm = wrap(0, -181);
+    t.equal(norm.lat, 0);
+    t.equal(norm.lon, 179);
+    t.end();
+  });
+  test('negative longitude wrapping - 271 degrees', function (t) {
+    var norm = wrap(0, -271);
+    t.equal(norm.lat, 0);
+    t.equal(norm.lon, 89);
+    t.end();
+  });
+  test('negative longitude wrapping - 361 degrees', function (t) {
+    var norm = wrap(0, -361);
+    t.equal(norm.lat, 0);
+    t.equal(norm.lon, -1);
+    t.end();
+  });
+  test('negative longitude wrapping - 631 degrees', function (t) {
+    var norm = wrap(0, -631);
+    t.equal(norm.lat, 0);
+    t.equal(norm.lon, 89);
+    t.end();
+  });
+  test('negative longitude wrapping - 721 degrees', function (t) {
+    var norm = wrap(0, -721);
+    t.equal(norm.lat, 0);
+    t.equal(norm.lon, -1);
+    t.end();
+  });
+};
+
+module.exports.all = function (tape, common) {
+  function test(name, testFunction) {
+    return tape('SANTIZE wrap ' + name, testFunction);
+  }
+
+  for( var testCase in module.exports.tests ){
+    module.exports.tests[testCase](test, common);
+  }
+};