概述

借用上篇文章中二阶贝塞尔曲线的生成，本文实现mapboxGL中的航线动画。

效果

实现

1. 初始化地图

const from = [101.797439042302, 36.5937248286007];
const to = [106.9733, 35.217];
const points = new ArcLine(from, to);
const line = new Geometry(points, "LineString")const style = {version: 8,sources: {XYZTile: {type: "raster",tiles: ["http://webrd01.is.autonavi.com/appmaptile?x={x}&y={y}&z={z}&lang=zh_cn&size=1&scale=1&style=8","http://webrd02.is.autonavi.com/appmaptile?x={x}&y={y}&z={z}&lang=zh_cn&size=1&scale=1&style=8","http://webrd03.is.autonavi.com/appmaptile?x={x}&y={y}&z={z}&lang=zh_cn&size=1&scale=1&style=8","http://webrd04.is.autonavi.com/appmaptile?x={x}&y={y}&z={z}&lang=zh_cn&size=1&scale=1&style=8",],tileSize: 256,},LineVector: {type: "geojson",data: line,},},layers: [{id: "XYZTile",type: "raster",source: "XYZTile",minzoom: 0,maxzoom: 22,},{id: "LineVector",type: "line",source: "LineVector",paint: {"line-color": "#f00","line-width": 3,},},],
};const map = new mapboxgl.Map({container: "map",style,attributionControl: false,center: [104.74329766269716, 35.80025022526921],zoom: 8,pitch: 60,bearing: getAngle(from, to)
});

2. 添加飞机

map.on('load', () => {// 添加动态图标map.loadImage('../css/icon.png', function(error, image) {if (error) throw errormap.addImage('flyline-icon', image)map.addSource('flyline-point', {'type': 'geojson','data': new Geometry(from, 'Point')})map.addLayer({'id': 'flyline-point','source': 'flyline-point','type': 'symbol','layout': {'icon-image': 'flyline-icon','icon-size': 0.4,'icon-allow-overlap': true,'icon-rotation-alignment': 'map','icon-pitch-alignment': 'map','icon-rotate': 0}})
})

3. 开始动画

const count = 500
const length = turf.length(line)
const interval = length / count
let index = 0
let playFunction = () => {if(index > count) {clearInterval(playFlag)} else {const point = turf.along(line, index * interval)const pointP = turf.along(line, index * interval * 0.8)map.getSource('flyline-point').setData(point)const rotate = getAngle(pointP.geometry.coordinates, point.geometry.coordinates)map.setLayoutProperty('flyline-point', 'icon-rotate', rotate)setView(pointP.geometry.coordinates, rotate + 90)index++}
}
let playFlag = setInterval(playFunction)
playFunction()/ / 设置视图
function setView(center, angle) {map.setBearing(angle);map.setCenter(center);
}// 计算角度
function getAngle(coords1, coords2) {return turf.bearing(turf.point(coords1),turf.point(coords2)) - 90
}