geojson-vt/test/test-simplify.js

Slice GeoJSON data into vector tiles efficiently

'use strict';

var simplify = require('../src/simplify'),
    t = require('tape');

var points = [
    [0.22455,0.25015],[0.22691,0.24419],[0.23331,0.24145],[0.23498,0.23606],
    [0.24421,0.23276],[0.26259,0.21531],[0.26776,0.21381],[0.27357,0.20184],
    [0.27312,0.19216],[0.27762,0.18903],[0.28036,0.18141],[0.28651,0.17774],
    [0.29241,0.15937],[0.29691,0.15564],[0.31495,0.15137],[0.31975,0.14516],
    [0.33033,0.13757],[0.34148,0.13996],[0.36998,0.13789],[0.38739,0.14251],
    [0.39128,0.13939],[0.40952,0.14114],[0.41482,0.13975],[0.42772,0.12730],
    [0.43960,0.11974],[0.47493,0.10787],[0.48651,0.10675],[0.48920,0.10945],
    [0.49379,0.10863],[0.50474,0.11966],[0.51296,0.12235],[0.51863,0.12089],
    [0.52409,0.12688],[0.52957,0.12786],[0.53421,0.14093],[0.53927,0.14724],
    [0.56769,0.14891],[0.57525,0.15726],[0.58062,0.15815],[0.60153,0.15685],
    [0.61774,0.15986],[0.62200,0.16704],[0.62955,0.19460],[0.63890,0.19561],
    [0.64126,0.20081],[0.65177,0.20456],[0.67155,0.22255],[0.68368,0.21745],
    [0.69525,0.21915],[0.70064,0.21798],[0.70312,0.21436],[0.71226,0.21587],
    [0.72149,0.21281],[0.72781,0.21336],[0.72998,0.20873],[0.73532,0.20820],
    [0.73994,0.20477],[0.76998,0.20842],[0.77960,0.21687],[0.78420,0.21816],
    [0.80024,0.21462],[0.81053,0.21973],[0.81719,0.22682],[0.82077,0.23617],
    [0.82723,0.23616],[0.82989,0.23989],[0.85100,0.24894],[0.85988,0.25549],
    [0.86521,0.26853],[0.85795,0.28030],[0.86548,0.29145],[0.86681,0.29866],
    [0.86468,0.30271],[0.86779,0.30617],[0.85987,0.31137],[0.86008,0.31435],
    [0.85829,0.31494],[0.85810,0.32760],[0.85454,0.33540],[0.86092,0.34300],
    [0.85643,0.35015],[0.85142,0.35296],[0.84984,0.35959],[0.85456,0.36553],
    [0.84974,0.37038],[0.84409,0.37189],[0.84475,0.38044],[0.84152,0.38367],
    [0.83957,0.39040],[0.84559,0.39905],[0.84840,0.40755],[0.84371,0.41130],
    [0.84409,0.41988],[0.83951,0.43276],[0.84133,0.44104],[0.84762,0.44922],
    [0.84716,0.45844],[0.85138,0.46279],[0.85397,0.47115],[0.86636,0.48077]
];

var simplified = [
    [0.22455,0.25015],[0.26776,0.21381],[0.29691,0.15564],[0.33033,0.13757],
    [0.40952,0.14114],[0.4396,0.11974],[0.48651,0.10675],[0.52957,0.12786],
    [0.53927,0.14724],[0.56769,0.14891],[0.61774,0.15986],[0.62955,0.1946],
    [0.67155,0.22255],[0.72781,0.21336],[0.73994,0.20477],[0.76998,0.20842],
    [0.7842,0.21816],[0.80024,0.21462],[0.82077,0.23617],[0.85988,0.25549],
    [0.86521,0.26853],[0.85795,0.2803],[0.86779,0.30617],[0.85829,0.31494],
    [0.85454,0.3354],[0.86092,0.343],[0.84984,0.35959],[0.85456,0.36553],
    [0.84409,0.37189],[0.83957,0.3904],[0.8484,0.40755],[0.83951,0.43276],
    [0.85397,0.47115],[0.86636,0.48077]
];

t('simplifies points correctly with the given tolerance', function (t) {
    simplify(points, 0.001);

    var result = [];
    for (var i = 0; i < points.length; i++) {
        if (points[i][2] > 0.005 * 0.005) {
            result.push([points[i][0], points[i][1]]);
        }
    }
    t.same(result, simplified);
    t.end();
});