javascript - 合并高级视图定位和视图动画功能
问题描述
前段时间我在 gis.stackexchange 中发布了一个问题,但并没有为我解决太多问题。我现在要在这里试试。
我正在尝试合并显示为 OL 示例的两个函数,即Advanced View Positioning和View Animation。我可以使用动画方法成功更改视图,但无法像高级视图定位方法中那样修复缩放。我正在使用这些方法来更改 OL 中加载的一些栅格的视图。我的问题仅与缩放级别有关,如何使其适合我正在使用的栅格?我相信我需要获取栅格范围(已经这样做了)并以某种方式计算并链接到 flyTo() 函数中的缩放部分。
OL版本:5.3
我用于动画的功能:
//This is one of the locations I using with the View Animation method
var randomLocation = transform(getCenter([565280.904542, 6924581.621580, 565319.267400, 6924554.342636]), 'EPSG:31982', 'EPSG:3857');
function flyTo(location, done) {
var duration = 3000;
var zoom = view.getZoom();
var parts = 2;
var called = false;
function callback(complete) {
--parts;
if (called) {
return;
}
if (parts === 0 || !complete) {
called = true;
done(complete);
}
}
view.animate({
center: location,
duration: duration
}, callback);
view.animate({
zoom: zoom - 2,
duration: duration / 2
}, {
zoom: zoom,
duration: duration / 2
}, callback);
}
一些相关但对我没有帮助的链接(其中大多数使用该fit(extent)
功能。我尝试使用它但它取消了该animate()
功能。在我链接用户@Mike 的 gis.stackexchange 问题中能够合并这些功能,但是它不适用于栅格范围):
解决方案
基于 2 月 15 日对原始问题的回答的第二次编辑的工作片段
proj4.defs("EPSG:31982","+proj=utm +zone=22 +south +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs");
if (ol.proj.proj4 && ol.proj.proj4.register) { ol.proj.proj4.register(proj4); }
var view = new ol.View({
center: [0, 0],
zoom: 1
});
var map = new ol.Map({
layers: [
new ol.layer.Tile({
source: new ol.source.OSM()
})
],
target: 'map',
controls: ol.control.defaults({
attributionOptions: {
collapsible: false
}
}),
view: view
});
var flytoparqueorion = document.getElementById('flytoparqueorion');
flytoparqueorion.addEventListener('click', function() {
var oldCenter = view.getCenter();
var oldZoom = view.getZoom();
var extent = ol.proj.transformExtent([565280.904542, 6924581.621580, 565319.267400, 6924554.342636], 'EPSG:31982', 'EPSG:3857');
view.fit(extent, {padding: [170, 50, 30, 150], constrainResolution: false});
var newCenter = view.getCenter();
var newZoom = view.getZoom();
view.setCenter(oldCenter);
view.setZoom(oldZoom);
flightZoom = Math.min(oldZoom, newZoom) - 2;
zoomUp = oldZoom - flightZoom;
zoomDown = newZoom - flightZoom;
var duration = 2000;
var parts = 2;
var called = false;
function callback(complete) {
--parts;
if (called) {
return;
}
if (parts === 0 || !complete) {
called = true;
//done(complete);
}
}
view.animate({
center: newCenter,
duration: duration
}, callback);
view.animate({
zoom: flightZoom,
duration: duration * zoomUp / (zoomUp + zoomDown)
}, {
zoom: newZoom,
duration: duration * zoomDown / (zoomUp + zoomDown)
}, callback);
}, false);
.mapcontainer {
position: relative;
margin-bottom: 20px;
}
.map {
width: 1000px;
height: 600px;
}
div.ol-zoom {
top: 178px;
left: 158px;
}
div.ol-rotate {
top: 178px;
right: 58px;
}
.map div.ol-attribution {
bottom: 30px;
right: 50px;
}
.padding-top {
position: absolute;
top: 0;
left: 0px;
width: 1000px;
height: 170px;
background: rgba(255, 255, 255, 0.5);
}
.padding-left {
position: absolute;
top: 170px;
left: 0;
width: 150px;
height: 400px;
background: rgba(255, 255, 255, 0.5);
}
.padding-right {
position: absolute;
top: 170px;
left: 950px;
width: 50px;
height: 400px;
background: rgba(255, 255, 255, 0.5);
}
.padding-bottom {
position: absolute;
top: 570px;
left: 0px;
width: 1000px;
height: 30px;
background: rgba(255, 255, 255, 0.5);
}
.center {
position: absolute;
border: solid 1px black;
top: 490px;
left: 560px;
width: 20px;
height: 20px;
}
<link rel="stylesheet" href="https://cdn.rawgit.com/openlayers/openlayers.github.io/master/en/v5.3.0/css/ol.css" type="text/css">
<script src="https://cdn.polyfill.io/v2/polyfill.min.js?features=requestAnimationFrame,Element.prototype.classList,URL"></script>
<script src="https://cdn.rawgit.com/openlayers/openlayers.github.io/master/en/v5.3.0/build/ol.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/proj4js/2.5.0/proj4.js"></script>
<div class="mapcontainer">
<div id="map" class="map"></div>
<div class="padding-top"></div>
<div class="padding-left"></div>
<div class="padding-right"></div>
<div class="padding-bottom"></div>
<div class="center"></div>
</div>
<button id="flytoparqueorion">Fly to Parque Orion</button>