Synthetic Lines

Synthetic lines example.

main.js

import 'ol/ol.css';
import Feature from 'ol/Feature';
import LineString from 'ol/geom/LineString';
import Map from 'ol/Map';
import VectorLayer from 'ol/layer/Vector';
import VectorSource from 'ol/source/Vector';
import View from 'ol/View';
import {Stroke, Style} from 'ol/style';

const count = 10000;
const features = new Array(count);

let startPoint = [0, 0];
let endPoint;

let delta, deltaX, deltaY;
let signX = 1;
let signY = -1;

// Create a square spiral.
let i;
for (i = 0; i < count; ++i) {
  delta = (i + 1) * 2500;
  if (i % 2 === 0) {
    signY *= -1;
  } else {
    signX *= -1;
  }
  deltaX = delta * signX;
  deltaY = delta * signY;
  endPoint = [startPoint[0] + deltaX, startPoint[1] + deltaY];
  features[i] = new Feature({
    'geometry': new LineString([startPoint, endPoint]),
  });
  startPoint = endPoint;
}

const vector = new VectorLayer({
  source: new VectorSource({
    features: features,
    wrapX: false,
  }),
  style: new Style({
    stroke: new Stroke({
      color: '#666666',
      width: 1,
    }),
  }),
});

const view = new View({
  center: [0, 0],
  zoom: 0,
});

const map = new Map({
  layers: [vector],
  target: 'map',
  view: view,
});

index.html

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8">
    <title>Synthetic Lines</title>
    <!-- Pointer events polyfill for old browsers, see https://caniuse.com/#feat=pointer -->
    <script src="https://unpkg.com/elm-pep@1.0.6/dist/elm-pep.js"></script>
    <!-- The lines below are only needed for old environments like Internet Explorer and Android 4.x -->
    <script src="https://cdn.polyfill.io/v3/polyfill.min.js?features=fetch,requestAnimationFrame,Element.prototype.classList,TextDecoder"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/core-js/3.18.3/minified.js"></script>
    <style>
      .map {
        width: 100%;
        height:400px;
      }
    </style>
  </head>
  <body>
    <div id="map" class="map"></div>
    <script src="main.js"></script>
  </body>
</html>

package.json

{
  "name": "synthetic-lines",
  "dependencies": {
    "ol": "6.13.1-dev"
  },
  "devDependencies": {
    "parcel": "^2.0.0"
  },
  "scripts": {
    "start": "parcel index.html",
    "build": "parcel build --public-url . index.html"
  }
}