Files
openlayers/examples/canvas-gradient-pattern.js
2022-07-30 09:48:10 -06:00

46 lines
1.3 KiB
JavaScript

import KML from '../src/ol/format/KML.js';
import Map from '../src/ol/Map.js';
import VectorLayer from '../src/ol/layer/Vector.js';
import VectorSource from '../src/ol/source/Vector.js';
import View from '../src/ol/View.js';
import {DEVICE_PIXEL_RATIO} from '../src/ol/has.js';
import {fromLonLat} from '../src/ol/proj.js';
// Gradient and pattern are in canvas pixel space, so we adjust for the
// renderer's pixel ratio
const pixelRatio = DEVICE_PIXEL_RATIO;
// Generate a rainbow gradient
const canvas = document.createElement('canvas');
const context = canvas.getContext('2d');
const gradient = context.createLinearGradient(0, 0, 1024 * pixelRatio, 0);
gradient.addColorStop(0, 'red');
gradient.addColorStop(1 / 6, 'orange');
gradient.addColorStop(2 / 6, 'yellow');
gradient.addColorStop(3 / 6, 'green');
gradient.addColorStop(4 / 6, 'aqua');
gradient.addColorStop(5 / 6, 'blue');
gradient.addColorStop(1, 'purple');
const vectorLayer = new VectorLayer({
background: 'white',
source: new VectorSource({
url: 'data/kml/states.kml',
format: new KML({extractStyles: false}),
}),
style: {
'fill-color': gradient,
'stroke-width': 1,
'stroke-color': '#333',
},
});
const map = new Map({
layers: [vectorLayer],
target: 'map',
view: new View({
center: fromLonLat([-100, 38.5]),
zoom: 4,
}),
});