Example of rendering geometries to an arbitrary canvas.
This example shows how to render geometries to an arbitrary canvas.
import 'ol/ol.css';
import {Circle as CircleStyle, Fill, Stroke, Style} from 'ol/style';
import {LineString, Point, Polygon} from 'ol/geom';
import {toContext} from 'ol/render';
const canvas = document.getElementById('canvas');
const vectorContext = toContext(canvas.getContext('2d'), {size: [100, 100]});
const fill = new Fill({color: 'blue'});
const stroke = new Stroke({color: 'black'});
const style = new Style({
fill: fill,
stroke: stroke,
image: new CircleStyle({
radius: 10,
fill: fill,
stroke: stroke,
}),
});
vectorContext.setStyle(style);
vectorContext.drawGeometry(
new LineString([
[10, 10],
[90, 90],
])
);
vectorContext.drawGeometry(
new Polygon([
[
[2, 2],
[98, 2],
[2, 98],
[2, 2],
],
])
);
vectorContext.drawGeometry(new Point([88, 88]));
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Render geometries to a canvas</title>
<!-- Pointer events polyfill for old browsers, see https://caniuse.com/#feat=pointer -->
<script src="https://unpkg.com/elm-pep"></script>
<!-- The line below is 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,URL,TextDecoder,Number.isInteger"></script>
<style>
.map {
width: 100%;
height:400px;
}
</style>
</head>
<body>
<canvas id="canvas"></canvas>
<script src="main.js"></script>
</body>
</html>
{
"name": "render-geometry",
"dependencies": {
"ol": "6.6.1"
},
"devDependencies": {
"parcel": "^2.0.0-beta.1"
},
"scripts": {
"start": "parcel index.html",
"build": "parcel build --public-url . index.html"
}
}