1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
| import Feature from 'ol/Feature.js';
import Map from 'ol/Map.js';
import View from 'ol/View.js';
import {Circle} from 'ol/geom.js';
import {OSM, Vector as VectorSource} from 'ol/source.js';
import {Style} from 'ol/style.js';
import {Tile as TileLayer, Vector as VectorLayer} from 'ol/layer.js';
import {fromLonLat} from 'ol/proj.js';
const columbusCircleCoords = fromLonLat([-73.98189, 40.76805]);
const labelTextStroke = 'rgba(120, 120, 120, 1)';
const labelText = 'Columbus Circle';
let pointerOverFeature = null;
const renderLabelText = (ctx, x, y, stroke) => {
ctx.fillStyle = 'rgba(255,0,0,1)';
ctx.strokeStyle = stroke;
ctx.lineWidth = 1;
ctx.textAlign = 'center';
ctx.textBaseline = 'middle';
ctx.font = `bold 30px verdana`;
ctx.filter = 'drop-shadow(7px 7px 2px #e81)';
ctx.fillText(labelText, x, y);
ctx.strokeText(labelText, x, y);
};
const circleFeature = new Feature({
geometry: new Circle(columbusCircleCoords, 50),
});
circleFeature.set('label-color', labelTextStroke);
circleFeature.setStyle(
new Style({
renderer(coordinates, state) {
const [[x, y], [x1, y1]] = coordinates;
const ctx = state.context;
const dx = x1 - x;
const dy = y1 - y;
const radius = Math.sqrt(dx * dx + dy * dy);
const innerRadius = 0;
const outerRadius = radius * 1.4;
const gradient = ctx.createRadialGradient(
x,
y,
innerRadius,
x,
y,
outerRadius
);
gradient.addColorStop(0, 'rgba(255,0,0,0)');
gradient.addColorStop(0.6, 'rgba(255,0,0,0.2)');
gradient.addColorStop(1, 'rgba(255,0,0,0.8)');
ctx.beginPath();
ctx.arc(x, y, radius, 0, 2 * Math.PI, true);
ctx.fillStyle = gradient;
ctx.fill();
ctx.strokeStyle = 'rgba(255,0,0,1)';
ctx.stroke();
renderLabelText(ctx, x, y, circleFeature.get('label-color'));
},
hitDetectionRenderer(coordinates, state) {
const [x, y] = coordinates[0];
const ctx = state.context;
renderLabelText(ctx, x, y, circleFeature.get('label-color'));
},
})
);
const map = new Map({
layers: [
new TileLayer({
source: new OSM(),
visible: true,
}),
new VectorLayer({
source: new VectorSource({
features: [circleFeature],
}),
}),
],
target: 'map',
view: new View({
center: columbusCircleCoords,
zoom: 19,
}),
});
map.on('pointermove', (evt) => {
const featureOver = map.forEachFeatureAtPixel(evt.pixel, (feature) => {
feature.set('label-color', 'rgba(255,255,255,1)');
return feature;
});
if (pointerOverFeature && pointerOverFeature != featureOver) {
pointerOverFeature.set('label-color', labelTextStroke);
}
pointerOverFeature = featureOver;
});
|
)
