79c8afdba8
To have the same path (starting with `ol/`, without `.js`) as in the documentation. The support was added in the webpack config in #8928
94 lines
2.9 KiB
JavaScript
94 lines
2.9 KiB
JavaScript
import Map from 'ol/Map';
|
|
import View from 'ol/View';
|
|
import TileLayer from 'ol/layer/Tile';
|
|
import {fromLonLat} from 'ol/proj';
|
|
import BingMaps from 'ol/source/BingMaps';
|
|
import {getRenderPixel} from 'ol/render';
|
|
|
|
const key = 'As1HiMj1PvLPlqc_gtM7AqZfBL8ZL3VrjaS3zIb22Uvb9WKhuJObROC-qUpa81U5';
|
|
|
|
const imagery = new TileLayer({
|
|
source: new BingMaps({key: key, imagerySet: 'Aerial'})
|
|
});
|
|
|
|
const container = document.getElementById('map');
|
|
|
|
const map = new Map({
|
|
layers: [imagery],
|
|
target: container,
|
|
view: new View({
|
|
center: fromLonLat([-109, 46.5]),
|
|
zoom: 6
|
|
})
|
|
});
|
|
|
|
let radius = 75;
|
|
document.addEventListener('keydown', function(evt) {
|
|
if (evt.which === 38) {
|
|
radius = Math.min(radius + 5, 150);
|
|
map.render();
|
|
evt.preventDefault();
|
|
} else if (evt.which === 40) {
|
|
radius = Math.max(radius - 5, 25);
|
|
map.render();
|
|
evt.preventDefault();
|
|
}
|
|
});
|
|
|
|
// get the pixel position with every move
|
|
let mousePosition = null;
|
|
|
|
container.addEventListener('mousemove', function(event) {
|
|
mousePosition = map.getEventPixel(event);
|
|
map.render();
|
|
});
|
|
|
|
container.addEventListener('mouseout', function() {
|
|
mousePosition = null;
|
|
map.render();
|
|
});
|
|
|
|
// after rendering the layer, show an oversampled version around the pointer
|
|
imagery.on('postrender', function(event) {
|
|
if (mousePosition) {
|
|
const pixel = getRenderPixel(event, mousePosition);
|
|
const offset = getRenderPixel(event, [mousePosition[0] + radius, mousePosition[1]]);
|
|
const half = Math.sqrt(Math.pow(offset[0] - pixel[0], 2) + Math.pow(offset[1] - pixel[1], 2));
|
|
const context = event.context;
|
|
const centerX = pixel[0];
|
|
const centerY = pixel[1];
|
|
const originX = centerX - half;
|
|
const originY = centerY - half;
|
|
const size = Math.round(2 * half + 1);
|
|
const sourceData = context.getImageData(originX, originY, size, size).data;
|
|
const dest = context.createImageData(size, size);
|
|
const destData = dest.data;
|
|
for (let j = 0; j < size; ++j) {
|
|
for (let i = 0; i < size; ++i) {
|
|
const dI = i - half;
|
|
const dJ = j - half;
|
|
const dist = Math.sqrt(dI * dI + dJ * dJ);
|
|
let sourceI = i;
|
|
let sourceJ = j;
|
|
if (dist < half) {
|
|
sourceI = Math.round(half + dI / 2);
|
|
sourceJ = Math.round(half + dJ / 2);
|
|
}
|
|
const destOffset = (j * size + i) * 4;
|
|
const sourceOffset = (sourceJ * size + sourceI) * 4;
|
|
destData[destOffset] = sourceData[sourceOffset];
|
|
destData[destOffset + 1] = sourceData[sourceOffset + 1];
|
|
destData[destOffset + 2] = sourceData[sourceOffset + 2];
|
|
destData[destOffset + 3] = sourceData[sourceOffset + 3];
|
|
}
|
|
}
|
|
context.beginPath();
|
|
context.arc(centerX, centerY, half, 0, 2 * Math.PI);
|
|
context.lineWidth = 3 * half / radius;
|
|
context.strokeStyle = 'rgba(255,255,255,0.5)';
|
|
context.putImageData(dest, originX, originY);
|
|
context.stroke();
|
|
context.restore();
|
|
}
|
|
});
|